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Showing results for tags '4.2l'.
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I have a question about an article I read on 4WDMechicx.com when researching converting a CJ to TBI. The article can be found here: https://www.4wdmechanix.com/MSD-Atomic-EFI-for-Jeep-4.2L-Inline-Six?r=1 I have a 1980 CJ-7 with the 258 I6 engine. It was sold to me non-op and is missing some emissions parts that are hard to find and expensive. Going in my plan was to convert it to fuel injection to increase reliability, economy and make emissions testing easy. I found the above article that was very informative and well written. I dug into the details and have some questions. The article points to emissions testing in California a few times and I was hopeful that I could also put a MSD Atomic system on my Jeep. This was appealing to me because I put a MSD billet distributor, 6A spark control and a Blaster 2 coil on the Jeep. The Atomic system would work hand-in-hand with my ignition system and allow me to program advance curves. When I dug into the details I found that the Atomic system that was installed was part number 2900. Here is a direct link: https://www.holley.com/products/fuel_systems/fuel_injection/atomic_efi/atomic_efi_tbi/parts/2900. This appears to be an older system than the Atomic 2 offerings but is the only fuel injection system sold by MSD or Holley that is California legal. Scroll down to the Emissions heading and you'll see that is is legal under C.A.R.B. EO #D-722. I Googled EO D-722 and found this page:. http://ww2.arb.ca.gov/sites/default/files/classic/msprog/aftermkt/devices/eo/d-722.pdf. In reading the EO I see that the vehicles that this system is authorized for road use in California are GM vehicles made in 1987 and earlier with a V8 engine. California Executive Orders call out the specific vehicles the subject part can be used on. For example I have a MSD 8516 billet distributor on my Jeep. This is the EO for that part:. https://arb.parts/Executive-Order/D-40-39. If you scroll down to Exhibit A it lists 1993 and older AMC inline 6 cylinder engines under the 8516 part number. The point is the EO lists applications for each EO and if a vehicle is not called out in the EO the part is not legal for use on that vehicle. Getting back to the Atomic conversion in the article:. How were you able to pass a visual inspection when the Atomic system in not called out in the EO? In the past some smog shops would accept a CARB stickered conversion without checking the EO. I'm not sure that is the case now. If so putting this system on a Jeep is somewhat of a gamble. If a smog tech reads the EO the vehicle will fail. In that case the TBI will need to be replaced with a compliant part. The cost of the Atomic system is high - too high for me to risk a failing visual inspection. It seems to me that the only option for a fuel injected conversion on a CJ in California is Howell TBI. Please let me know if I'm missing something with the Atomic system and CARB legality. I've researched this for weeks and don't see how it can be legally used on the streets of California when installed on a Jeep with a AMC 258. Thank you, Bob Elliott -
Depending upon the year and engine source, 4.2L AMC/Jeep®/I-H version timing covers can be different than a 4.0L cover. The TDC mark may be many degrees away from the 4.0L damper mark, which is typically the damper used in a Mopar EFI conversion. Determine the true TDC for #1 piston when referencing TDC; this is determined by measuring the piston's position in #1 cylinder with the spark plug removed. The piston must stand at its peak when determining TDC. Note: Inexpensive TDC tools are available at Summit, Amazon and elsewhere: https://www.summitracing.com/parts/sum-900189 or TDC tool at Amazon. I prefer the Amazon listed tool for its yielding contact with the piston and gauge. If your damper mark does not match up with #1 piston TDC, place the #1 piston at true TDC and scribe a timing mark on the damper to match the timing cover's TDC mark. You can add MSD or similar degree tape. For accuracy, make sure the tape matches your damper's diameter! This is one builder’s 4.0L/4.6L experience. He has a 4.0L long block from a ’98 TJ Wrangler and installed an OE 4.2L/258 crankshaft. The 4.2L crankshaft keyway did not match his OE 4.0L crankshaft keyway position: “I had stashed away parts from the 4.2 that I stole the crankshaft from to build my Stroker. Last night I dug out the timing cover and put it next to the one from my 4.0. Now I see why the notch in the harmonic balancer doesn’t line up with the tab on the 4.0 cover! The woodruff key slot on the 4.2 is cut in a different location than the key slot on the 4.0 course crank… This might be one for the forums- probably most people never even look since the timing marks won’t be used to set distributor timing but some people like me will be very confused if they do.”* *Footnote: The 258/4.2L timing cover and crankshaft source was an early seventies I-H 4.2L (AMC) inline six. The I-H/AMC 4.2L crankshaft with a unique key-way offset is the holy grail 12-counterweight type. When you're sourcing parts, know the origins of the crankshaft and the original timing cover's TDC and advance/retard tab location on the cover. 4.2L Crankshaft with 4.0L damper and timing cover. 4.2L timing cover (top) and 4.0L timing cover (bottom). Know which parts you have and always index the timing cover TDC mark with precise TDC of #1 piston. Moses -
The timing cover on a 4.2L is different than the 4.0L. TDC mark is many degrees away from the 4.0L damper mark, which is typically the damper used in a Mopar EFI conversion. Use true TDC for #1 piston when referencing TDC. If your damper mark does not match up with #1 piston TDC, place the #1 piston at true TDC and scribe a timing mark on the damper to match the timing cover TDC. This is one builder’s 4.0L/4.6L experience. He has a 4.0L in a ’98 TJ Wrangler and installed an OE 4.2L/258 crankshaft. The 4.2L crankshaft keyway did not match his OE 4.0L crankshaft keyway position: “I had stashed away parts from the 4.2 that I stole the crankshaft from to build my Stroker. Last night I dug out the timing cover and put it next to the one from my 4.0. Now I see why the notch in the harmonic balancer doesn’t line up with the tab on the 4.0 cover! The woodruff key slot on the 4.2 is cut in a different location than the key slot on the 4.0 course crank… This might be one for the forums- probably most people never even look since the timing marks won’t be used to set distributor timing but some people like me will be very confused if they do.” 4.2L Crankshaft with 4.0L damper and timing cover. 4.2L timing cover (top) and 4.0L timing cover (bottom). Know which parts you have and always index the timing cover TDC mark with precise TDC of #1 piston. Moses
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I recently became the owner of a 1982 CJ8 with a 4.2. I have installed a HEI distributor, Holley Sniper BBD fuel injection on the jeep. I have replaced oil pan, rear main seal and valve cover gaskets in an attempt to stop the oil leaks but the rear main leak has gotten the best of my patience. The body is rough but serviceable and the engine runs ok but leaves a lot to be desired in the get up and go department. I would like to build a stroker engine and stay with a Jeep six cylinder. I would like to know if I can use the HEI distributor and fuel injection that I already have on a 4.6 build. -
For finding TDC on the compression stroke without the starter functioning, a time-honored approach is a whistle that fits into the spark plug hole for #1 piston. Spark plugs removed to ease crankshaft rotation, this device allows rotating the crankshaft by hand in the normal direction of rotation while listening for the whistle as the piston rises on the compression stroke. Note: If you have brazing or soldering equipment, you can make this tool using an old spark plug shell with the porcelain, electrode and ground strap removed. Braze or solder a metal whistle to the metal plug shell. Remove any burrs or debris from the "tool", then thread it into the spark plug hole for #1 plug in this case. For a pre-made type, here's a popular and inexpensive example that uses a rubber stopper instead of a threaded base. You'll get the idea: https://www.amazon.com/Innovative-Products-7894-Flexible-Compression/dp/B000TQ16HG. An alternative is to use a compression gauge installed in #1 cylinder spark plug hole. Plugs removed, rotate the crankshaft and watch for the bump in compression as the piston rises on the #1 compression stroke. Simultaneously watch the crankshaft damper timing mark to make sure you're rising to #1 TDC. Once the piston is at TDC (look down the #1 spark plug opening and confirm that the piston is at its peak with the TDC mark aligned on the crank pulley/damper), you can decide where you want to place the #1 spark plug wire in the cap rotation. Allow enough room for the distributor's vacuum canister to rotate back and forth without interference when you set the spark timing. Lift the distributor away from the camshaft drive to align the distributor shaft and rotor with a selected distributor cap position for the #1 spark lead. Then you can hook up the remaining spark leads in clockwise rotation, following the firing order: 1-5-3-6-2-4. There is a preferred position for #1 wire in the cap, traditionally around the 5:30 to 6-o'clock position on a CJ Jeep inline six. Without EFI and using a conventional HEI/DUI distributor like you're doing, you can select whatever cap position you want for #1 wire lead. Just make sure the rotor points to that position at TDC for #1 piston on the compression stroke. Allow enough room for distributor movement to fine tune the spark timing. Install spark leads following the 1-5-3-6-2-4 Jeep inline six firing order. Moses
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Hi, I've been dealing with an overheating behavior in my YJ 1989 Wrangler (4.2L with all emissions control hooked up except pulse air system, Carter BBD, Auto Trans). Long time ago I've replaced cooling fluid, It was 100% tap water that is the worst choice due to corrosion; so I decided to replace it by an ethylene glycol mix as you can find them ready to pour into your cooling system. I don't know if the coolant was poor quality but immediately after replacing the fluid I was getting the engine overheated. Perhaps it was air trapped in the system as the guy replacing the coolant did all the procedure really quick with the engine still warm... Well I had to go back to water again and the issue was solved. No more overheating during next days. Then I went wheeling several months after, when stopped the vehicle heared something like a pressurized air leak, it was the hose from the thermostat housing to the intake manifold, was cracked and ended up blown after I pulled it. So I shortened the hose and reinstall it again. Got home with overheating issues again. Bought all new hoses, including upper and lower radiator hoses. Heater was disabled so former owner plug the nipple coming from the water pump and the one on the back of the intake manifold as well, I didn't enable the heater yet but I have connected a hose between those two points to keep coolant flow through the manifold and cylinder head. Found that there was no thermostat installed, so installed one. Inspected water pump, a little bit of corrosion but the rotor and impeller was good, no play at the shaft. Refilled all the system with 50/50 mix and have to add some distilled water as I got short of coolant to top up the radiator. Fan clutch was replaced as well. I've been having random overheating, it is worst when A/C is turned on, obviously because the condenser is in front of the radiator. But sometimes runs good and the needle does not go above 210. I do not know where the needle it is supposed to be when the cooling system is working as it should. There are sometimes that random misfiring is happening, not too critical but I'm sure I'm not getting a perfect tuned engine. I've replaced the radiator cap just to discard this is the troublemaker. (13lb new one installed) Does the water to coolant swap have something to do with making debris and metal corrosion to become loose and start building a sediment inside the engine's block?
