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Discussion Starter · #1 ·
I just installed the mopar fuel injection kit it my 89 4.2 wrangler. For some reason, it still misses and everything was changed(plugs,wires). Does anyone know why? Also, it has a very rough idle at start up and sometimes stalls. If anyone can help me, I would appreciate it. Thanks

 
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Discussion Starter · #2 ·
I have the same Mopar EFI kit that you have, but I have not finished getting mine up on the road yet. If you can't get any help from
anyone here call HESCO Inc. 205-251-1472, or e-mail them at [email protected]. Their web site is www.hescosc.com. From what
I understand these are the people who actually put together this EFI kit. I have talked to them in the past and they are very
knowledgable about how to make it run right. I tried the Mopar Performance hotline and they did not have a clue about this kit. I
would love to hear how this turns out for you, as I will be following in your footsteps soon.
Good luck,
Ethan
 
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Discussion Starter · #3 ·
I have recently purchased the MPI kit and am also doing the 4.0 head swap on my 81 CJ-7. I haven't installed the MPI kit yet so If yall learn something on how to do it better or get it running right post it cause like Ethan said, I'll be following in yalls footsteps here very soon myself. Thanks, Joel

 

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Make sure you have power to computer at all times. If it loses power it has to relearn each time and will run like s#@t for first 15 minutes. I had same problem with mine, it was on a circuit that temporarily lost power when the key was being switched. Now I have it hooked directly to hot lead, and no problems.

Enjoying Montana's Big Sky (& rocks & rivers & mountians etc, You get the picture.)
 

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I just want to clear up one thing. You say it still misses. Do you mean it missed before the swap? If so , then it could be a burnt valve or collapsed lifter or something that didn't get changed during the swap. If you mean that it's just been doing it since the swap, than maybe check that you have good fuel pressure. You can buy a fuel injection pressure gauge tester at autozone for about 30 bucks. It is invaluable for diagnosing fuel problems. It screws into the fuel rail, where you will see a threaded connection sort of like a tire valve. Also check that the fuel return line to the fuel tank is not clogged. Making sure the computer memory has a constant 12 volts as mentioned earlier is good also.
Good luck


Greg
89 XJ, 83 CJ-7, 79 Blazer, 67 CJ-5
 
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