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79 cj7 Renegade engine issue

79 cj7 Renegade engine issue

WMarshburn

Jeeper
Posts
17
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Location
Fredericksburg, VA
Vehicle(s)
1979 Jeep CJ7 Renegade AMC304
I just purchased our first Jeep, and it a CJ7 Renegade with the AMC 304 v8 and wow, what an engine, that is if it is in neutral. I have a major issue with the engine right now in which i was looking for some direction. When in neutral i can throttle her all the way and she sounds so good, but as soon as we put her in gear i can not give it more than about a quarter throttle and that is if we feather it down or she will backfire and stall. We have put new plugs, wires, dist. cap, rotor, checked timing. I was going to replace the solonoid however someone said if its running already than its more likely a vacuum leak.

I apprectiate all the input and will keep everyone in the loop on the rebuild and restore project.

Thanks
 
i appreciate the input. I will be finishing the new vacuum lines today and in reguards to the intake, it was leaking a hair in the back and found the rear bolts were way loose, snuged em up and it stopped getting air. Hopefully i have enough time to check the timing when in gear just put her up on some stands and see what we got going on, thanks for the input so far!
 
I am going to follow this very closely, I have the exact same thing happening. My jeep is a 76 CJ7 with AMC 304 auto QuadraTrac . I have replaced coil, distributor , cap , rotor and module. Finally got mine cranked but it is running like yours. I just had my carb re-built last summer. Good Luck!!!
 
Sorry for the delayed follow up postings have been out of town the last few days, while redoing all the vacuum hoses i wanted to change the CTO vacuum ports since they are original and one of the nipple's was broken completely, anyone know where to pick some new ones up?

Any yes it has the automatic
 
Last edited:
One of you guys that is more into automatics than I am. Isn't there a modulater valve or something like that, that would affect the engine when the Transmission is in gear??
:cool:

Sorry for the delayed follow up postings have been out of town the last few days, while redoing all the vacuum hoses i wanted to change the CTO vacuum ports since they are original and one of the nipple's was broken completely, anyone know where to pick some new ones up?

Any yes it has the automatic
 
Ok, all the vacuum lines have been swapped withe new ones and same result,:mad:, You can rev it up all you want in park and neutral and she will not hesitate, but put it in gear you think she is pulling a house up a mountain, no throttle response and bogs down till it stalls. Timing seems to check out as well, running out of options, still praying it was something i am overlooking or simple . . . . . but those are starting to fizzle out.
 
YEA finally after 6 weeks of chasing problems, I got my CJ running today, purring like a kitten. A family member suggested I put the original ignition control module back on, I did and she stopped all that backfiring and advanced like a race car. The new module was obviously bad. Hope this helps with your problem, worth a shot.
 
Not an expert on automatics, but there is a linkage from the throttle to the Transmission related to shift points. Mine came off its roller/track and put a bind on the throttle linkage so that it either wouldn't accelerate or, if it did, wouldn't drop back to idle.
My ole AMC 258 i6 / 4.2l started acting up recently and I finally found a crack in the vacuum line to the brake booster.
 
I finally got it running 80-90% power. I wanted to thank everyone for all the help and tips, the problem was all of the above lol, after the vacuum lines, timing, coil, plugs, carb gasket, and many other things i found a simple vacuum line going from the rear of the engine to the Transmission had completely split and the previous owner stuck a bolt to plug it not letting vaccum get to the tranny was the main coprate, now i need to get a new diaphram that the vacuum attaches to on the tranny and i expect shell be rolling down the road at 80 again.

Thanks again everyone!
 
:d:d:d:d

one of you guys that is more into automatics than i am. Isn't there a modulater valve or something like that, that would affect the engine when the Transmission is in gear??
:cool:
 

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