For a while now my car has been a nightmare. When it's cold, it acts as normal. You car smoke the tires from a stop, and smoke them from a break stand. However, when it gets warmed up it stumbles and is difficult to get off the line. The hotter the engine gets, the worse the car performs.

So far I have new wires, cap, rotor, ignition module, tested resistance accross injectors, new O2 sensor, checked fuel pressure, and am currently using another ECM to rule that one out.

I was out in the car tonight and with the engine temp at 185*, from a roll the acceleration wasn't that bad, not the best, but acceptable. When it heats up to 215* it gets noticably worse, and from a stop it's dire. What I didn notice was this. If I keep the rpm at around 3000 the O2 stays pretty close to 14.7. Below that, like if I'm just cruising in a high gear the O2 is reading more towards lean. I checked the voltage accross the fuel pump and it's good.

I'm running out of ideas and need to find what the problem is. I didn't get any use or fun out of this car all of last year and don't want this comming year to be the same. So, please, help me.

Thanks for the time


Robert

 

how's the cts? have you replaced it yet?

 

Yes, I've replaced that also. I'm stumped.

 

Check fo vacum leaks and did u replace your pcv valve ? my car was doin kinda the same thing it ended up being the hose going to the pcv valve had hole in it.

 

Haven't checked the pcv valve.

 

have you tried running it with the maf disconnected? how does it run in limp mode?

 

I just went out in the car for a short run. It was running crap the whole time. The other night when I went out I had just finished charging the battery. I went out tonight with the scanner and the battery volts was 14.0 and the voltage accross the fuel pump was 13.7. Does this look normal?

The car threw a code 33 on me tonight also. High voltage (low vacuum) at mass air flow sensor. Whatever thst means?? Next time I'm out I'll disconnect the MAF and reset the codes.

Any ideas?

I should add, it's an 87 LB9 IROC.