Getting fed up...bucking/bogging/popping

[Tbird232ci]

This section is getting all too familiar.

I can't figure this out. I'll do my best to describe the issues I'm having.

If I start the car up after it sitting for a few hours, and getting cool, I can go drive it, and it will make all sorts of power, blazing tires, and run decent. Once it gets up to operating temps, it starts to bog when I give throttle input, it'll pop through the throttle body, then take off.

Now the bogging and popping issue is much worse. The car will bog and pop all the way to work and back, and sometimes clear up. I went through and finally set my cam timing properly, since I set it to the best of my knowledge before. No change, if anything, it may be worse.

While I'm driving at any steady speed, I will lightly touch the gas, and it will bog, and actually slow down.

The car has a known-good DC computer and MAP, known good air charge sensor, a questionable HEP (once I get some time to hit the post office, I'll have an 86 LM and distributor on it's way, and a brand new HEP), all the vacuum lines are sound, cam and ignition timing are set by the book, and a few of the websites, new fuel pump and filter, most of the basics have been gone over.

Anything else I can check into? I'm getting completely frustrated, I can't even travel 15 miles without fear of breaking down or other issues.

[turbovanman²]

My first check would be fuel pressure using a guage taped to the windshield and going for a drive. What your describing is a lean issue. It could be bad map or computer but I would try that first.

[OmniLuvr]

are you only having problems at part throttle, or WOT too? sounds like maybe a tps, and you can check that using the book and a voltmeter. i would deff. CHECK that first, O2 sensors will affect part throttle, and hep sensor problems will make your head spin. i might have one for the 85 electronics, maybe you could try that one before you put 86 electronics in.

the 86 lm is designed for the swirl head, not the bath tub head, and you will have a timing curve issue. what head casting do you have on your head, i assumed it was 287 because you said it was an 85. if you have the 782, then you will need the 86 lm for your engine to function properly.

fuel pressure could be a big issue as turbovanman stated, and have you hooked up a boost gauge yet, very important for tuning and diagnosis.

[boboli]

Sorry about your continuing problems, seems to be contagious to omni's! Have you looked at the piece under the hep, the shutter piece that is attached to a plastic base with plastic rivets. Mine was very loose so the shutter part moved while it was rotating and made the car run like crap.

[butchsuppe]

My first check would be fuel pressure using a guage taped to the windshield and going for a drive. What your describing is a lean issue. It could be bad map or computer but I would try that first.

I agree, check fuel pres. before anything else.

[1984rampage]

Check the pins at the logic module connectors. Four of mine were corroded pretty badly and were causing me all sorts of problems. I soldered new ones on and it all seems to have cleared up! Also check your tps sensor, injector wiring, and your injectors to make sure its all functioning properly... I fought the same issue as you for a while and it was a -----!

[boboli]

I agree with 1984rampage, check your lm pins. I am going through my wiring harness and all the resistance I've found were not from bad or worn wiring like I thought but were caused by some pins in the lm. I had to change some as well to remove the resistance. Making sure they aren't corroded may solve your problem.

[Tbird232ci]

Sorry I haven't updated you guys. I've had a lot of BS going on.

Anyways, all of the LM pins were nice and tight, clean, and no issues. I checked those when I put the DC LM in it.

I swapped a spare map in it and the issue got a bit better. I swapped another map in, and it got a bit better, but didn't clear up. Since that didn't fix the issue completely, I decided to run the vacuum line from the map to the junction under the hood. I get to under the hood, and find the line was coming off of the baro solenoid. I put that on, zip tied it, and it fixed the bucking and popping issue.

As for the lagging, I'm a bit stumped. I did the 4 wire conversion but didn't solder the wires yet since I'm waiting until I get my a/f gauge wired in. I pulled codes and got a 52. 52 means that it runs rich, but cannot run lean. This points to my O2 sensor, or my fuel pressure being too high.

My next angle of attack is soldering the O2 wires, and if that doesn't help, I'll have to try to find a gauge. I had one a while back but have no idea where it is anymore.

[86turboz]

I am going through almost the same exact thing as you and still havent figured it out...it is making me insane