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Moses Ludel

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About Moses Ludel

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    Reno Area...Nevada
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    Family, destination four-wheeling and dual-sport motorcycling, photography, videography, fly-fishing, anthropology, automotive mechanics and welding/metallurgy.

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  1. Hi, Bill...Thanks for your interest in my book...Your engine year is right for the 60-way PCM (1991-95 YJ Wrangler 4.0L). The 1995 YJ Wrangler 4.0L two-rail EFI was the original prototype for Mopar's first generation Mopar EFI Conversion Kit. Second generation Mopar EFI Conversion kits use the 1997-99 single rail fuel injection/induction system with a modified pressure regulator (1997-up style mounted in a machined remote housing). The second generation kits still used a 60-way PCM (1991-1995 style). The Mopar wiring harness should fit a 60-way PCM like the one that came with your 1994 4.0L engine. If you got the PCM with the engine, you have the 60-way (60-pin) PCM. I did a quick search and found the Mopar parts listing at the link below. It shows a P5007148AB wiring harness that replaces both the P5007148 and P5007149 harnesses. The price seems competitive: https://www.moparamerica.com/oem-parts/mopar-harness-p5007148ab This image for a P5007148AB harness appears to be a 60-way. Note that this harness has the single 60-way/pin plug connector that you need for a 1994 donor PCM. The wide plug with a bolt through the center is 60-way: This Mopar Performance harness number should accommodate both the later single-rail or earlier two rail EFI kits. If the PCM connector is 60-way/pin, this should work with your 1994 engine and 1994 (1991-95 style) PCM. Your two-rail EFI system requires a return fuel line to the fuel tank, which is not an issue. Your '82 CJ-8 chassis has that provision. When you receive your copy of my Jeep CJ Rebuilder's Manual 1972-86 (Bentley Publishers, available at Bentley Publishers, Advance Adapters and other book outlets), you will find coverage and details about the two-rail Mopar EFI conversion kit installation. I did that conversion with an '84 CJ-7 Jeep, using a first generation, two-rail Mopar EFI Conversion Kit. The approach will be similar for your 1994 YJ 4.0L EFI engine if you have the original donor EFI/induction system, ignition distributor and PCM. Let us know how the wiring and overall conversion turn out. This should be a significant improvement whether the 4.0L remains stock or becomes a 4.6L stroker build. If you are considering a 4.6L stroker build with your 258/4.2L crankshaft, the fuel injectors should be upgraded to 302 Ford H.O. type for adequate flow rate. I cover this in detail at the magazine, including injector tuning. Do a key word search for "4.6L" at the magazine. Moses
  2. JP88YJ...Curious if the valves are sealing. Was the engine using oil? Good sign about the cross-hatch. "Wayne" and I had a constructive, sensible approach as he rebuilt his 2.5L, a later MPI type though much like what you would be doing. Since this appears the direction you've taken, I recommend going through our exchange on Wayne's engine rebuild, which turned out very well without an out-of-chassis boring. Wayne did meticulous micrometer reads and held honing to precisely the amount needed and nothing more...You may be able to do this if wear is similar to his 2.5L, your measurements will tell: The cylinder head work will be a sublet. Depending upon head decking, check the pushrod lengths with a CompCams gauge after the cylinder head work and installation—before selecting new pushrods. A new camshaft, lifters and timing set is always part of the build. You may need more machining and parts, depending upon the wear you find. That will determine whether the engine stays in the chassis or not. Moses
  3. JP88YJ...Did you run a compression test or, better yet, a leakdown test before pulling the cylinder head? What do the cylinder walls look like? Is there noticeable taper? A cylinder ridge above the top ring(s)? The fourth cylinder looks like low compression, which could be from valve leakage and/or worn piston rings. The wear I describe is part of diagnosis. Disassembly of the valves will reveal any valve seat, valve stem or valve face wear. However, before removing any valves or loosening springs, run a quick check of the valve sealing. With the intake/exhaust ports facing upward, carefully fill the ports with a solvent. Watch the valve seat-to-face areas for liquid leaking between the valve faces and seats. Some photos of the cylinder walls with the pistons lowered in each cylinder would be helpful. We can assess the condition of the block, which in turn indicates piston ring wear. (Without a leakdown test, this is the remaining means for assessing ring wear.) Also check the piston to cylinder wall clearances with the pistons lowered about 3/4-inch below the block deck. Moses
  4. Glad you joined this exchange, CJChris. There should be a growing need for the information, as the 2000-up C-O-P engines and Grand Cherokee inline 4.0L engines through 2004 are increasingly available. I'm pleased that jordan89oak started this topic and brought late inline six features to light. Your follow-up details on the late Wrangler engines should be helpful, too. As for mating late chassis wiring to earlier vehicles, the bigger obstacles are anti-theft/security measures that involve the steering column and PCM. This came up years ago when the 2.8L CRD diesel from the 2005/06 KJ Liberty was a target for CJ and Wrangler swaps. The idea followed the export Wrangler concept. Installers quickly discovered that the key interlock security system in the Liberty created wiring and PCM issues. KJ steering columns, PCMs and wiring harnesses were allegedly needed for the swap. Perhaps there were simpler workarounds. If you're handy with FSM wiring schematics, there should be easier workarounds for your late TJ Wrangler 4.0L swap into a CJ7. The HESCO wiring harness seems an easier route, though the original HESCO harnesses worked with the 60-way PCM (1991-95 style). Please let us know whether that harness is worthwhile for your swap. Many use the donor engine's PCM and harnesses, working their way through splices and chassis hook-ups. For any splices involving PCM wiring circuits, I always use rosin core solder and twist splices as illustrated in the 4.0L era FSMs. Several layers or thicker heat shrink can be used for insulation. Any more, I avoid crimp connectors for electrical work beyond utility trailer lighting. (Even there, I use weather-tight, heat shrink end connectors.) You need moisture proof connections that do not create resistance issues. Crimp connectors are ohms resistance troubles in the making. Moses
  5. Tdu659...Very pleased that Bennie helped solve your problem. Interesting that the MAP, IAC and barometric feedback from the PCM does not compensate, but maybe those functions are curtailed or limited in the late conversion kit. I recall that the late kit still uses the 1991-95 60-way PCM with the later (OBD-II era, 1997 up) single rail EFI...If the hole solves the problem, Bennie has likely encountered this before on high altitude applications. Regarding the pressure drop, which EFI kit do you have? The later single rail type with the regulator/filter unit remotely mounted near the fuel tank? This regulator is essentially a 1997-up TJ Wrangler type tank/module regulator with the EFI conversion kit's machined adapter housing, which allows remote mounting of the filter/regulator...The earlier two-rail systems have the regulator at the fuel rail and a return fuel line to the fuel tank. The factory in-tank pumps do have a check valve that helps prevent fuel and pressure drainback. Remote "universal" pumps will often have a check valve as well. (You mention changing the fuel pump, so I'm unclear about its design or features.) If you have the single rail system with the remote mount pressure regulator, this regulator doubles as a check valve for easier restarts. If the system is bleeding down as quickly as you describe, the regulator could be at fault and not holding pressure for a restart. That sounds like the case from your description. Until you remedy the check valve (filter/regulator if the later kit) issue, try "priming" the system before cranking the engine. Turn the key just to the ON position and listen for the pump operation. The pump should run until the pressure is up. You may need to recycle the key more than once to reach full pressure. Once pressure is up, crank the engine over. It should start immediately. If there is an overall pressure issue at the fuel rail, even when the engine is running, that could be the regulator or pump. 52 PSI should be enough pump pressure, though, as long as there is sufficient volume flow at that pressure. (Actual fuel pressure at the fuel rail should be 49.2 PSI +/- 5 PSI on a single rail system, so 52 PSI would be right in there for pressure.) After confirming pump pressure and volume, I would troubleshoot the pressure regulator's check valve function. Moses
  6. sassylady...When you photograph (cell phone level works well in tight quarters), concentrate on the sheet metal body sills (rocker panels), the actual frame, the fuel and brake pipes and any rust that draws your attention. We'll take a close look and go from there. Moses
  7. There are areas where you should not use dielectric grease, RTV sealant or anti-seize paste. One worth mentioning is certain oxygen sensors (O2 devices). Some O2 sensors draw ambient air where the wires enter the sensor housing. Sometimes There is a port like the vent opening shown in the illustration below. These O2 sensors depend on ambient air for a baseline voltage reading. Deviations from that point trigger the PCM/ECM/ECU to adjust or "trim" fuel mixtures. Be certain that you know where the O2 sensor's ambient air port or ambient air entry point is located. If at the connector, do not put dielectric grease, RTV sealant or anti-seize paste where it could block this air source. Know the type of O2 sensor used and how or where it draws ambient air. This generic O2 sensor image shows the vent to atmosphere. Air is sometimes sourced through a padding where the wires enter the top of the sensor. Do not plug this port or the area where the wires enter the top of the sensor: For more information on O2 sensors, Walker Products has a training guide on O2 sensors that is helpful. The guide explains the functions, troubleshooting and service needs of O2 sensors. Proper use of anti-seize on threads of new sensors is illustrated: https://www.walkerproducts.com/wp-content/uploads/2020/06/Oxygen-Sensor-O2-Training-Guide.pdf Moses
  8. There are areas where you should not use dielectric grease, RTV sealant or anti-seize paste. One worth mentioning is certain oxygen sensors (O2 devices). Some O2 sensors draw ambient air where the wires enter the sensor housing. Sometimes There is a port like the vent opening shown in the illustration below. These O2 sensors depend on ambient air for a baseline voltage reading. Deviations from that point trigger the PCM/ECM/ECU to adjust or "trim" fuel mixtures. Be certain that you know where the O2 sensor's ambient air port or ambient air entry point is located. If at the connector, do not put dielectric grease, RTV sealant or anti-seize paste where it could block this air source. Know the type of O2 sensor used and how or where it draws ambient air. This generic O2 sensor image shows the vent to atmosphere. Air is sometimes sourced through a padding where the wires enter the top of the sensor. Do not plug this port or the area where the wires enter the top of the sensor: For more information on O2 sensors, Walker Products has a training guide on O2 sensors that is helpful. The guide explains the functions, troubleshooting and service needs of O2 sensors. Proper use of anti-seize on threads of new sensors is illustrated: https://www.walkerproducts.com/wp-content/uploads/2020/06/Oxygen-Sensor-O2-Training-Guide.pdf Moses
  9. WranglerFIN...Well, the silver lining to all of this is that each of these components wear over time. Their duty cycle will now be renewed uniformly. You've given the entire fuel system a renewal. Let us know how the new injector performs. You likely will need to fine adjust the pressure to 14-15 PSI on the new injector. Moses
  10. sassylady...Is this the rust scourge at work? There are several types and degrees of rust. For simpler non-perforating rust, you can find rust arresting products that transform surface rust into harmless oxides that can be primed and painted. POR-15 is one such product, popular for vehicle "frame-off" restoration projects. Prior to using POR-15, all paint, debris, wax and grease must be removed. POR-15 and similar products should not be used around intact, painted surfaces. There is also an insidious kind of rust—from the inside out. This rust reveals itself too late—as exfoliation. Exfoliation pushes paint away as it unfolds from rusted, underlying metal. The area is eroding and becomes unstable and weak. I give a repair example in my Jeep® Owner's Bible™ (Bentley Publishers). The CJ-5's body tub required a small sheet metal section to be cut out and replaced by fresh sheet metal. I bought the vehicle at San Diego, CA, but it came from Chicago, IL. That was my first exposure to road salt damage. Today, road salt rust is so prolific that one company makes replacement frame sections for TJ Wrangler Jeep® vehicles. Frames rust from the inside out, exfoliating as the section breaks or collapses. The frame, essentially useless, can be weld repaired and made functional. This company does a brisk business thanks to road salt, coastal salt air and drivers wending their way through the surf at Baja. Then there is today's epidemic of rusted fuel and brake lines. At the magazine, you can find my coverage of how to repair, reconstruct and form brake tubing. I cover brake and fuel line work thoroughly. In my research, I discovered an entire "industry" related to repairs and replacement of brake and fuel tubing, most often the result of road salt damage. Vehicle age is immaterial, the key factor is the amount of salt exposure. In some cases, coastal air or extreme humidity can erode brake and fuel tubing: https://www.4wdmechanix.com/video-series-how-to-flare-automotive-brake-tube-fuel-lines-and-cooler-tubing/ https://www.4wdmechanix.com/how-to-fabricating-restoring-and-repairing-hydraulic-brake-lines/ If you could post some photos of the rust you see, I can identify the risks posed and suggest an approach for eliminating the rust. Once the rust has been identified and eliminated, I'll suggest ways to prevent rust from forming. Moses
  11. manderson72...Mike...I'm puzzling why the main gallery could be plugged after that kind of commercial vat cleaning unless debris was, literally, packed into that passage or brush cleaning did not back up the vat tanking. Bore brush cleaning is the only assurance of open passageways....Any solution with the engine still in the chassis is worth pursuing. Did you thoroughly clear out the oil passages in the tubular pushrods before installing them? If necessary, I like your idea of dropping the pan and looking for debris and bearing material before taking the step of removing the engine from the chassis. The Mahle head gasket at 0.040" is a slight bump in compression over the OEM head gasket (typically 0.052" +/-). This would make the head set slightly lower than with a Mopar gasket. A lower head height would increase the lifter preload. I would check pushrod lengths before disassembly. This will provide some insight; measure the pushrod lengths when removed...After the head is back in place and torque'd to spec, install the rockers and use the gauge to determine correct pushrod lengths at the right lifter preloads. Do not order pushrods until the engine is assembled and the final preload(s) can be checked. If you change head gasket sources, there will not be an issue. I agree with your latest approach and would rule out all other possibilities before removing the engine and disassembling it: oil pump, pickup, oil filter adapter and flow to main gallery, clogged (accessible) passageways that can be tested and reached with the block in place, etc., etc. Definitely remove the oil filter and open it up carefully to inspect for metal (especially bearing overlay, babbitt and debris) in the filter pleats. This can be very revealing. Do this before dropping the oil pan. You may have enough answers here. Fortunately, dropping the pan with a one-piece gasket is not major work. (Fel-Pro makes a great replacement gasket that comes with plastic threaded plugs that temporarily hold the gasket corners in place when working overhead.) Checking the oil screen, tube and pump, looking for debris in the pan and so forth makes sense before the bigger step of pulling the engine. Also, though I'm sure you have looked at this, be certain that the distributor drive gear (Camshaft Position Sensor/oil pump drive gear on later C-O-P engines) is intact and that the oil pump drive slot and the distributor tang engage properly. Moses
  12. manderson72...As much work as that seems, there's apparently either no flow or inadequate flow of oil into or through the main gallery. A remote possibility is oil pump cavitation from the screen tube not sealing at the pump, the pump gasket not sealing or an oil filter adapter somehow blocking flow. Though these are unlikely possibilities, you can read normal oil pressure without enough oil flow volume. Cavitation from oil pickup leakage can reduce oil flow. If you do need to change the screen, use an oil pump screen installation tool. They sell for as low as $20 and reduce risk of damaging the tube during installation. If there is bearing debris floating through the engine, the new oil pump pickup screen could be clogging. Pulling the engine down now may save the new crankshaft and cam bearings. When you have the cam out, inspect the cam bearings and their alignment holes with the galleys. Make sure there are no restrictions anywhere in the oil passageways. You mentioned block "vatted" cleaning. Was this done at a machine shop? They usually remove the gallery plugs before tanking a block. This step specifically addresses stubborn or impacted debris in passageways. There are bore brushes and flushing tools available from Goodson Tools (professional grade) and elsewhere that can scour and flush the main gallery and other critical oil passageways. Install new replacement block plugs when you open up the main oil gallery for flushing. Dorman, Pioneer and others offer these plugs, often as a "kit" with new freeze plugs. If you get the Goodson Tools, brushes or improvise with a similar brushing and pressure flushing approach, you can do this work at home. Some items related to gallery cleaning that you will find helpful: https://goodson.com/collections/oil-gallery-tools Considering the amount of bearing material that circulated with the original oil pressure loss, the block passageways and even the crankshaft passageways would need cleaning. Observe what comes out during cleaning and flushing: You want a clear explanation for the current lack of oil circulation through the lifters. Take apart your new oil pump and inspect for debris or any damage. Clean the pump. Reverse flush the oil pump screen (still attached to the pump). Inspect the screen carefully with a magnifying glass. If debris is visible or suspected, replace the screen. The crankshaft passageways could have debris if the main gallery was not thoroughly clean during engine assembly. The main gallery is past the oil filter. If you plan to reuse the new bearings, inspect bearings for any signs of embedded debris. Cut the oil filter apart and inspect pleats for signs of metal debris...Install fresh oil and a new oil filter before start-up. Your new lifters should be set aside in their removed order. Install them in the same bores to match lifter/lobe contact patterns (even though the engine only ran briefly). I would carefully disassemble each lifter and clean out any debris. Make sure plungers move without restriction. Lube the lifter bases and sides with engine assembly/camshaft lube during installation but do not fill or "pump up" the lifters with oil. During valvetrain installation, the lifter plungers must be able to move. If filled with oil, the plungers will stay extended during initial cranking and can cause valves to hit the pistons on some engine types. Measure the pushrod lengths. If you did not machine the head or valves/seats, and if every pushrod is the same length, you likely have properly fitted pushrods from the original 505 build. (It's reasonable to assume that 505 checks lifter clearance and fits pushrod lengths. If you discover pushrods are different lengths, you need the CompCams gauge to determine where each pushrod should go.) You're not changing the heights of the valve stems or machining the head or block deck. If you either need or want to verify pushrod lengths and proper lifter clearance, you can invest in the CompCams gauge (a $20 item). Confirming lifter clearance is always a safe bet. When you reinstall the timing chain, make certain the valve timing is correct. Once the valvetrain (including pushrods and rocker arms) is fully assembled, you can prime the oiling system while hand rotating the crankshaft (battery disconnected!) to fill each of the lifters. This is easy to do with the spark plugs removed. Let us know what your find...You need to find something tangible that explains the lack of oil flow to the lifters. You can post photos if helpful. Moses
  13. Hi, ArkansasCrawler...Separating issues, it's worth mentioning that the EFI kit throttle linkage can be "jumpy" and hypersensitive. When Bill Burke and I taught Tread Lightly 4WD Clinics with off-pavement, low range driving, we would emphasize resting the right side of your accelerator foot against the transmission tunnel and rolling the throttle open by leaning your foot into the pedal. I bring this up to help determine whether the lurch at crawl speeds is EFI/MPI related or a hypersensitive throttle in bumpy crawl conditions. You indicate that the system has lurched at crawl speeds since the kit was installed. If the problem is not the pedal sensitivity, EFI system lurching is usually either a vacuum, Idle Air Control (IAC) or MAP issue. MAP issues can be vacuum related or loose electrical connections. Vacuum leaks should be chased down first, including the vacuum in the EVAP system and the check valve on the brake booster. If you have the earlier conversion system with the two-rail EFI and a fuel return to the fuel tank, the fuel return must be unrestricted and unaffected by fuel sloshing in the tank. The rollover check valves at the tank must be working properly to prevent fuel sloshing into the fuel filler system or affecting EVAP functions. A loose or poorly sealing fuel cap can create havoc, especially when jostling around off-pavement with fuel pressure changes and fuel sloshing around in the tank. Idle Air Control and MAP are possibilities. MAP is a perishable item over time. Before condemning the MAP sensor, I would check wiring, connectors and grounds, especially at the EFI splices into your chassis electrical. Grounds are critical...The MAP sensor is easy to replace if defective, but I'm not a fan of arbitrarily changing parts. The Idle Air Control Valve could be involved, though they are seldom defective. Check for vacuum leaks first, grounds and connections. The throttle position sensor might be involved here, a defective or out of voltage range TPS will create an unstable idle and tip-in condition, though usually at all times, not just when crawling. It's more likely that the Idle Air Control (IAC) would cause a surge condition. The TPS affects the rpm stability at idle, while the IAC tries to stabilize the idle speed to the factory/PCM rpm preset. This can sometimes create a drivability issue. Consider this: The IAC wants to stabilize the idle while you're braking against the engine in low range. If the idle lurching is an effort to stabilize the idle speed, some of this is unavoidable. The rpm might surge while you try to drop the engine speed below the factory preset for idle. Axle gearing and load involve other sensors that create an IAC response. You're off the throttle, but the IAC is on it! Some issues are inherent drivability quirks of EFI and the IAC's effort to hold rpm at a steady, often faster than desired speed. I recall testing the EFI/MPI Jeep 4x4s (1991-up Mopar systems) when new and discovering that the downhill behavior ("deceleration") in low range crawls was unsettling. The engines would struggle to hold a higher rpm while the vehicle was under braking in gear. ABS automatic brake pumping on loose down slopes was a whole other story. Here is how the Idle Air Control system works. See whether this is what your driving issue could be: "IDLE AIR CONTROL MOTOR DESCRIPTION...The IAC stepper motor is mounted to the throttle body, and regulates the amount of air bypassing the control of the throttle plate. As engine loads and ambient temperatures change, engine rpm changes. A pintle on the IAC stepper motor protrudes into a passage in the throttle body, controlling air flow through the passage. The IAC is controlled by the Powertrain Control Module (PCM) to maintain the target engine idle speed. OPERATION...At idle, engine speed can be increased by retracting the IAC motor pintle and allowing more air to pass through the port, or it can be decreased by restricting the passage with the pintle and diminishing the amount of air bypassing the throttle plate. The IAC is called a stepper motor because it is moved (rotated) in steps, or increments. Opening the IAC opens an air passage around the throttle blade which increases RPM. "The PCM uses the IAC motor to control idle speed (along with timing) and to reach a desired MAP during decel (keep engine from stalling). The IAC motor has 4 wires with 4 circuits. Two of the wires are for 12 volts and ground to supply electrical current to the motor windings to operate the stepper motor in one direction. The other 2 wires are also for 12 volts and ground to supply electrical current to operate the stepper motor in the opposite direction. To make the IAC go in the opposite direction, the PCM just reverses polarity on both windings. If only 1 wire is open, the IAC can only be moved 1 step increment) in either direction. To keep the IAC motor in position when no movement is needed, the PCM will energize both windings at the same time. This locks the IAC motor in place. In the IAC motor system, the PCM will count every step that the motor is moved. This allows the PCM to determine the motor pintle position. If the memory is cleared, the PCM no longer knows the position of the pintle. So at the first key ON, the PCM drives the IAC motor closed, regardless of where it was before. This zeros the counter. From this point the PCM will back out the IAC motor and keep track of its position again. When engine rpm is above idle speed, the IAC is used for the following: 1) Off-idle dashpot (throttle blade will close quickly but idle speed will not stop quickly) 2) Deceleration air flow control 3) A/C compressor load control (also opens the passage slightly before the compressor is engaged so that the engine rpm does not dip down when the compressor engages) 4) Power steering load control The PCM can control polarity of the circuit to control direction of the stepper motor. IAC Stepper Motor Program: The PCM is also equipped with a memory program that records the number of steps the IAC stepper motor most recently advanced to during a certain set of parameters. For example: The PCM was attempting to maintain a 1000 rpm target during a cold start-up cycle. The last recorded number of steps for that may have been 125. That value would be recorded in the memory cell so that the next time the PCM recognizes the identical conditions, the PCM recalls that 125 steps were required to maintain the target. This program allows for greater customer satisfaction due to greater control of engine idle. Another function of the memory program, which occurs when the power steering switch (if equipped), or the A/C request circuit, requires that the IAC stepper motor control engine rpm, is the recording of the last targeted steps into the memory cell. The PCM can anticipate A/C compressor loads. This is accomplished by delaying compressor operation for approximately 0.5 seconds until the PCM moves the IAC stepper motor to the recorded steps that were loaded into the memory cell. Using this program helps eliminate idle-quality changes as loads change. Finally, the PCM incorporates a 'No-Load' engine speed limiter of approximately 1800 - 2000 rpm, when it recognizes that the TPS is indicating an idle signal and IAC motor cannot maintain engine idle. A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the IAC motor through the PCM." There is a wire hook-up for checking stored PCM engine trouble codes with your EFI Conversion. On the earlier Mopar EFI Conversion system, I always hooked these wires to a dash LED lamp. There is a key-cycle check for codes. The key-cycling method and an LED lamp will work in the field. There is a scan tool/diagnostics connector built into the later Mopar EFI Conversion wiring harnesses. If your system has wiring with a diagnostics plug connector, it will likely take a Chrysler type scan tool adapter. This should provide some ideas. Separate the issues: driving challenges like the throttle jumpiness versus a mechanical issue. Take into account what the system is designed to do, including the IAC's functions and overrides when you're trying to maintain a slow idle. If this prompts questions, let me know... Moses
  14. manderson72...Focusing on the initial tear down condition and how the oil pressure stumbled down to zero, it sounds like the most likely culprit was oil starvation at some point, which damaged the bearings, and they gradually wore out. I would guess that with all bearings failed, the engine either ran dry of oil or experienced an extensive, extremely steep climb or descent that starved the engine for oil. The bearings scored badly, and bearing clearance increased at the damaged bearings. Oil pressure dropped from the camshaft, rod and main bearing oil bleed-off. Excessive bearing clearance or scoring will cause the damage you describe at the cam bearings. Rods and mains worn into the copper is a clear sign of rapid bearing wear, which usually originates with an oil starvation issue...As bearing clearance gets extreme, the oil pump volume is meaningless. Oil simply runs off the bearings without resistance, and therefore the oil pressure drops. At this point, unless you ran the engine for a while, priming would be a first step. Your priming method will work, use care not to damage the oil pump tangs. If the engine has already run considerably, priming will not make a big difference. Here is the explanation for oil flow/routing within your engine. Note that the oil goes from the full-flow oil filter directly into the block and to the main oil gallery. This gallery is the direct feed for the hydraulic lifters. No oil at the lifters, likely no oil to the camshaft bearings, crankshaft bearings, valvetrain or other critical areas in the engine. Read this through carefully: "OPERATION The pump draws oil through the screen and inlet tube from the sump at the rear of the oil pan. The oil is driven between the drive and idler gears and pump body, then forced through the outlet to the block. An oil gallery in the block channels the oil to the inlet side of the full flow oil filter. After passing through the filter element, the oil passes from the center outlet of the filter through an oil gallery that channels the oil up to the main gallery which extends the entire length of the block. Galleries extend downward from the main oil gallery to the upper shell of each main bearing. The crankshaft is drilled internally to pass oil from the main bearing journals (except number 4 main bearing journal) to the connecting rod journals. Each connecting rod bearing cap has a small squirt hole, oil passes through the squirt hole and is thrown off as the rod rotates. This oil throwoff lubricates the camshaft lobes, distributor drive gear, cylinder walls, and piston pins. The hydraulic valve tappets receive oil directly from the main oil gallery. Oil is provided to the camshaft bearing through galleries. The front camshaft bearing journal passes oil through the camshaft sprocket to the timing chain. Oil drains back to the oil pan under the number one main bearing cap. The oil supply for the rocker arms and bridged pivot assemblies is provided by the hydraulic valve tappets which pass oil through hollow push rods to a hole in the corresponding rocker arm. Oil from the rocker arm lubricates the valve train components, then passes down through the push rod guide holes in the cylinder head past the valve tappet area, and returns to the oil pan." If you follow the above description, you can see the possible trouble spots. There must be full volume and pressure of oil at the "main gallery". This feeds to virtually everything else except the rocker arms, which receive oil up through the pushrod tubes from the lifters. The lifters, of course, depend upon good oil pressure and oil flow volume at the main gallery. The key is getting good oil flow into the main gallery. Below are illustrations of lubrication flow for AMC/Jeep inline 232/258 engines. (Couldn't find these illustration in later Mopar FSMs.) In any case, this is similar to your 4.0L/4.6L: Trust this is helpful...Here if you need further assistance... Moses
  15. manderson72...So if I follow the sequence, it sounds like this 505 4.6L stroker long engine had an oiling issue that starved the main, rod and cam bearings for oil. The original problem may still be plaguing the rebuild that you just completed...Let's start with basics. You need to clarify why the engine lost oil pressure or had restricted flow in the first place. A functioning oil pump ("pressure okay") is not enough. Oil also needs to flow with proper volume through the lubrication system. First, some questions regarding how the original bearings failed: 1) Did you have what seemed like normal oil pressure when the original bearings failed? 2) Did you run the engine either without oil, low on oil or on a very steep incline that could have dry-sump'd the oil pump and starved the bearings of oil? 3) Was the oil pump screen in the correct position within the oil pan, submerged properly in oil and not creating a dry sump issue or failure to pick up oil? I am unclear about all the work you and your uncle have currently done. My concern is whether the camshaft bearings were changed and whether you are you using a new oil pump and pump gasket. Questions regarding the current light rebuild: 1) Did the machine shop install new camshaft bearings? (Bearings not installed in proper alignment will prevent oil flow through the lifters and to the crank bearings.) Was there any mention of a "spun cam bearing(s)"? Were the original cam bearing oil holes aligned with the block feed holes? 2) Is the oil pump pickup screen attached properly to the oil pump? With a new gasket? Is the gasket properly installed between the oil pump and block? 3) The debris from the original bearing failures would clog an oil pump pickup screen. Is the oil pump pickup screen new and tightly fitted into the pump body? 4) Did you prime the engine oiling system before start-up? 6) Is the oil filter stand the correct type for the engine and chassis? You have a YJ or TJ Wrangler? The issue with backfiring would not be surprising if the valves are not opening properly or reaching adequate opening height due to no prime. Of course, the valve timing (chain and sprockets) could be off mark. Before considering valve timing, however, if you did not prime the oiling system or there is no oil pressure registering on the gauge, prime the oiling system before trying to start the engine again. Note: Another cause of valves not seating is wrong pushrod length. You will find several discussions about the use of a CompCams pushrod gauge to check each pushrod's length. If pushrods were reused and installed in their original valve positions, this may not be an issue. Otherwise, if backfire persists after resolving the oil flow problem, check the pushrod lengths. This can be done with the cylinder head in position and rockers loosened. Follow these guidelines that we have discussed: Oil priming can be done by removing the distributor and using a priming tool to spin the oil pump with a stout (1/2-inch) variable speed drill motor. (I use a pressurized Goodson Tool oil canister, but for one-time use, that's way too costly.) I pull the coil wire or disconnect the battery to prevent engine firing and rotate the crankshaft with a ratchet and socket while priming the engine. This allows each lifter to prime without the pressure of valve opening on the lifter plunger. Valve springs should not be an issue. If the 505 build springs were for a performance camshaft, the springs should have enough seating force and spring height to work with the new camshaft you describe. Though not a likely problem from the work described, make sure the springs are not coil binding: compressing completely at full lobe lift and not allowing the rocker arms to move. Beyond that, 1,800 rpm should not create valve floating. Begin with separating issues. Until the lifters have oil (through priming with the pushrods and rocker arms installed and rockers torqued in place), there's no way to judge the lifter or valve opening heights. Begin by priming the oiling system unless something else in my questions or comments sparks a solution. Let us know what you find...I'll watch for your reply. Moses
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