New member - strange rich condition

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XakEp
Posts: 2
Joined: Mon Nov 04, 2019 9:38 pm

New member - strange rich condition

Post by XakEp » Mon Nov 04, 2019 9:44 pm

Well, glad to be a new member here, I managed to get my hands on a rather modified 1980 CJ7 with an AMC 360 and what appears to be a DIY TBI setup. When I start this thing up, it leaves a nice black blast of soot on the wall of my garage, and I can't figure out why. When I pull the plugs on each bank, I would expect one or both to be black, but they're not. They're slightly brown and not black at all. I noticed it idles high, around 1200 RPMs, but with this DIY TBI I'm not entirely sure of how to lower it and if it'll help me stop leaving Jackson Pollack paintings on the wall of my garage before my wife kills me.

Can someone point me in the right direction? I've been around modern cars, and this old school Jeep thing is awesome but I'm definitely on a learning curve going from EFI/standalone systems to 40 year old tech with TBI.

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Stuka
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Re: New member - strange rich condition

Post by Stuka » Mon Nov 04, 2019 9:52 pm

Well, welcome to the forum. Although this forum is dedicated for Full Size Jeeps (Wagoneers, 74-83 Cherokees, J-Trucks).

But, you do have a 360, which our rigs came with, so we should be able to help you out. I am going to move this to Fuel Injection tech, as I feel your issue lies with that.

The rich condition is most likely only on cold start if your plugs look ok. I am not sure which TBI you have, but many have a secondary cold start injector, and I am going to guess that your current tune has this set too high. You may need to put a new tune on it, and there are people here familiar with that.
1981 J10 AMC 258 with HEI and Weber 32/36 DGEV Carb, T176, NP208, D44/M23 with 4.56 gears and Detroit Locker, 6" lift, 33x12.50 Cooper STT's, BJ's Offroad Rear Dozer Bumper.
2017 JKU Rubicon Lifted and stuff
Pevious Jeeps: 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ


Topic author
XakEp
Posts: 2
Joined: Mon Nov 04, 2019 9:38 pm

Re: New member - strange rich condition

Post by XakEp » Thu Jan 02, 2020 1:14 pm

I'm still around - sorry if it looked like I abandoned the thread! Had to move and working on the Jeep had to take a backseat.

I've been pulling stuff apart, and it looks like this thing has a GM 7747 ECM in it. I have found the various sensors on the car (it runs, thankfully) but I'm trying to figure out how to get into the ECM to adjust the programming. I'll also be pulling the sensors (O2 etc) and testing with a multimeter to make sure they're good but that's secondary at the moment.

Any hints on how to at least datalog this beast?

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