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Showing results for tags '4.0l'.
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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 -
I'm trying to nail this down but unfortunately without any success. Jeep has around 27-9 psi pressure at rail at idle and vacuum connected. With disconnected vacuum it is around 36psi. I think this is main issue why my fuel trim numbers are 5-8%. Things done so far: Fuel filter has some 3k miles on it. Bypassed fuel filter and pressure is still the same. Cleaned and tested fuel injectors. All tested good. Checked vacuum lines Fuel tank had to be dropped for skid replacement, so I replaced fuel pump at the same time /w new strainer Replaced fuel pressure regulator with both o-rings Biggest difference happened when I replaced fuel pressure regulator. Vehicle would start around 30psi and will slowly drop down after warm up. I can't see any fuel dripping from regulator but I can smell fuel odor in vacuum line elbow. Smell was there even with the old regulator, I thought that it had shot diaphragm and replaced it. I really don't know where to look next, as I can't really see any fuel leaks and fuel consumption seems to be around normal... -
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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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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Well Moses I took your advice. I found a Cherokee Sport. It's a 2001 with little rust and 39,168 original miles on it. The information I have basically points to it last being registered in Vermont in 2007. Of course with every good thing comes a problem. I find a "barn find" in a manner of speaking, but I have yet to get it to start and run. I will post the pictures I took this evening after it got into my driveway. Yes, it was raining here this evening. To tell you what I'm thinking, I think it is a problem with ignition or the NPS. It turns over just fine, but there is no hint of firing. I've tried to start it in Park and Neutral without success. What do you think? $1500.00 was what I paid for it. The rust is at the very rear of the quarter panels and the drivers side rear wheel well, but I don't know just how extensive it is.
