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Everything posted by Lou

  1. Moses, thanks. Interesting suggestion regarding the battery. It has been in the Jeep for quite some time, but I try to keep a tender on it when it sits for a while. On a side note, I recently had a simlar situation with y motorcycle. I accidentally stalled it while getting ready to head out ion a ride. Then it wouldn't start and I had a bunch of fault codes. Though I feared bigger problems, it turned out to be a weak battery. I had a code for a 5 volt sensor. Not enough voltage to that and it inhibits starting and a chain reaction of other DTC's. I'll do a load test on my Jeep's battery and see what shape its in. If I remove the battery for a load test and re-install or replace it, will I need to drive for a week before I smog? Lou
  2. The great state of California and I once again disagree on how well my engine is running. Its an 82 CJ7 258ci with about 2500 miles since complete rebuild. Hesco MOPAR MPI kit added. And to me it seems to run great. But I failed smog due to high NO. All other tests (including HC and CO) passed. The strange thing is, the last time (two years ago) I passed no problem. Since then I have not made any changes. I did check faults and it was showing a code for the O2 sensor. Since I read that it is a common cause I thought I had my solution. Unfortunately when I went for a re-check it still did not pass. The smog guy asked if I drove the Jeep after replacing the O2 sensor to let the computer adjust operating parameters. But I had only driven it a few mile to the shop for a re-check. How far do I typically need to drive to get things to reset? The O2 sensor fault has not returned. Is there a way to know if the problem is gone without spending the money on another check? Lou
  3. A long overdue update to my situation... Pushrod replacement. Following the steps outlined in this forum, this is not a very difficult job. I purchased the CompCams tool and a set of 12" digital calipers. It takes some practice, and I went through all of my pushrods multiple times until my readings were very close and then took an average. In the end, there are only a few pushrod lengths available for any given engine. So I got as close as I could and ordered a lenght that would work best, bearing in mind there is the 0.020-0.060" pre-load range. There are kits available to make custom length rods if you really want the lengths perfect. However, it is a bit expensive, probably more geared to hot-rodders and racers looking for optimal performance. I did not see the need for my purposes. Though I consider this job a success, it did not solve my original problem of the engine misfiring or cutting out. Engine misfire/cut-out. Going back and re-thinking my symptoms, this continued to seem like a fuel flow issue. The engine just seemed like it was sputtering as though it was running out of gas. Having checked and/or replaced everything else in the fuel system (see previous sections of this post) I went back and looked at the basics of fuel/air induction. If the computer controls how much fuel (and its timing) to each injector, what gives the computer this information? Stepping on the throttle pedal only opens the butterfly valve to let in more air. Then it hit me that there must be a sensor which senses this flow change, sends a signal to the computer to cause the adjustment in fuel flow. Newer engines use a Mass Air Flow (MAF) sensor but this Mopar set up uses a Manifold Absolute Pressure (MAP) sensor. Now things made sense. I replaced it and my problem was solved. Always something new to learn. I hope this info helps someone else down the line. Lou
  4. Hi Moses. Thanks for the input. Based on my measurements, for most of the valves using a combination of the Melling MPR-301 and MPR-333 will give me a pre-load between 0.036" and 0.047". However four of them fall in between the two. See below preload for MPR-301/MPR-333: #1E (length 9.567) 0.027/0.055 #2I (length 9.571) 0.023/0.051 #2E (length 9.570) 0.024/0.052 #6I (length 9.565) 0.029/0.057 In your opinion, is it better to be too long or too short? Alternatively, should I consider adjustable length rods for these positions? Lou
  5. Hi Moses. I read and followed the information in your previous forum postings and bought the CompCams tool and removed the valve cover to check the pushrod lengths. Starting with #1 cylinder and working my way thru the firing order I carefully lined up each piston at TDC on its compression stroke making sure both valves were closed. Use of the CompCams tool is simple and straightforward. I went thru the measurement process several times since I had never done this before. Initially I tried using my old Vernier scale calipers, but it's only a 6" and I was struggling to measure the difference between my existing rods and the adjusted length of the CompCam tool. I ended up purchasing a 12" digital caliper resulting in faster, more accurate readings. Reviewing my notes and receipts from the engine build, .008 was removed off the block and .014 from the head. New intake and exhaust valves and new exhaust valve seats were installed; no mention of the intake seats so I assume they were ground. The pushrods were not replaced and all measured to be stock length of 9.7" plus or minus a couple of thousandths due to wear I suppose. Here are the results of my measurements in the order of intake/exhaust with the longest and shortest highlighted in red. The bigger variation between the intake and exhaust for #1 and #5 bothered me so I checked them again with the same result. 9.585/9.567 9.571/9.570 9.548/9.547 9.556/9.550 9.577/9.558 9.565/9.558 Looking at these measurements I feel my current pushrods are too long. Even taking the longest (9.585") and adding max preload of .060" gives 9.645" which is shorter than my existing 9.7" pushrods. So if I understand this process correctly, for a preload range of .030" to .060" would I be safe to shoot down the middle and add .045" to my measured length to acquire the required pushrod size and still have enough range on either end of the preload range to allow for the variation in length? Please let me know your thoughts. Lou
  6. Moses, thanks again for all of the input and advice and for directing me to the other forum exchange. That guy built a gorgeous Jeep! Yes, all components are installed exactly as outlined in the Hesco guideline. The pump and regulator are mounted along the frame rail just in front of the gas tank. The pre-filter is mounted aft of the cross over next to the floor pan, where the fuel lines converge, to get it farther away from the exhaust pipe. At least now I can eliminate fuel as a cause and move on. When I get a chance to get back out in the garage I'll definitely look into the electrical issues you suggest. I agree the CPS is far from perfect and its alignment has always been a concern for me. It doesn't sit square to the damper, so getting the right gap is difficult. I am going to check timing and get back to you. I find it interesting that the Hesco instructions specify timing should be 10-12 degrees, whereas my CJ shop manual (and sticker under the hood) specify 15deg +-1. Push rod length never occurred to me! I know the originals were re-used, the engine had a complete valve job and new valves installed and both block and head were resurfaced (-0.008 on the block and -0.014 on the head). Considering this was a stock rebuild and using the same head, I never gave the push rods a thought. I'm surprised the engine shop did not check this or advise me of the possibility. If nothing pans out on the electrical side I will pull the valve cover and check the push rod length (I like the tool from Comp Cams). To be continued next week... Lou
  7. Yes, I should have thought about the shrader valve. I was easily able to disconnect the fuel supply line from the rail. In addition, I was using an older battery I had in the garage with jumper wires connected to the pump. I realized that this battery was low on juice and not providing sufficient power to the pump. Once I changed to using the good battery in the Jeep and using the main fuel supply line I performed the test three times acquiring 300ml in 7 seconds. I should note that the engine is NOT a stroker. Its a stock rebuild; nothing fancy. However it is bored 0.040 over. I don't think this would result in a displacement or power increase that would require more pump flow/pressure? Yes, its the inline (external) pump. Orientation from the tank is filter, pump, regulator. With the flow and pressure in spec, where do I go from here? It is, of course, difficult to simulate in the garage a problem that occurs at speed under load. Lou
  8. Results from today's troubleshooting: I replaced the fuel filter and cut it open. The filter element is clean. The fuel flow produced a volume of 170ml in 7 seconds. I repeated this three times with identical results. This is low based on your information that it should put out 1/4 liter (250ml) in 7 seconds. This was with a new filter installed. I did not think to check the fuel flow with the old filter. Note: I checked the flow from the shrader valve port on the fuel rail. Is this correct? The fuel pressure reads 46psi at all operating RPM's and holds at least 30psi for more than 5 minutes. Do you suspect a bad pump? Or some other restriction? Lou
  9. Moses, Thanks for the reply. I have the single rail system. The pump and and regulator (both supplied with the kit) are mounted on the rear cross member as per the kit instructions and the stock mechanical fuel pump has been removed and the block off plate installed on the engine block. The fuel supply line runs from the pump and regulator up the passenger side (I used the existing stock line) and connects to EFI rated rubber fuel line which crosses under the radiator along the frame rail to the driver's side. So heat should not be an issue unless the injectors or fuel rail are getting excessive heat rising up from the exhaust manifold. I have a new gas tank installed, so I am doubtful of the clogged pick up sock. But I picked up a new fuel filter (located between the tank and pump) and will replace it precautionary. I'll cut it open and check for any debris. I will check the fuel flow and pressure later today or tomorrow and get back to you. Lou
  10. Hello. I'm new to the forum. I have an 82 CJ7 with a fresh rebuild 258 and the Hesco MPI installed by myself. At low power the engine runs fine. But under load, say going uphill or when giving a sudden throttle input in a higher gear, the engine begins to misfire or cut out as though one or more cylinders are not firing. If I ease up on the throttle it recovers. If not it shudders pretty bad until I do. If I go easy on the throttle the problem does not occur. Only under load. At cruise speed on the freeway it mostly runs good, but occasionally I do feel a slight power loss as though I am dragging a cylinder. The plugs are clean so I don't suspect an ignition issue. It acts like its running out of gas. Thoughts or suggestions much appreciated. Lou
  11. Hi. I'm new to this forum and have an 82 CJ7 with the 258 and the MPI set-up. I believe I am having the same issue with vapor lock. I'm wondering what fixed the issue for you? Thanks. Lou
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