Puffs black when cold

[torq455]

remember, only for about 30 seconds though.

[1988GTU]

The car is in open loop probably for that amount of time using default settings (Previous runtime/Factory specs) and when it goes closed the PCM tries to adjust/compensate for the extra fuel.

[Doubt_Incarnate]

if its just a warmup thing maybe the cold start enrichment value is putting to much gas in. if its something you can program maybe tune it down just a tad.

[torq455]

no, it's in open loop for about 2 mins. maybe a pinhole leak and it takes that long to clear the extra gas out. it didn't do this before at all. it is a 94 with 150k though. maybe it's time for a fuel psi diaphram.

[tractorman]

Sounds to me like your throttle position sensor is screwed up. They ain't too hard to check.

[torq455]

already checked that

[torq455]

-update- put the stock chip in, same problem. unpluged the vacuum to the fuel regulator, it worsened. i can hold rpm's to about 1400 right after starting for 30 secs or so,and it won't do the black puff chug deal--however, when i let off then it chugs again, like it still had to do it. so weird. any other ideas?

[torq455]

Yyyyyyeeeeaaaaahhhh!!!! fixed!!!!!

[PCGUY112887]

What was the issue?

[torq455]

TB was closed too much. I had to open it as far as the IAC step count would let me. Hot and without loads of any kind, and settled into an idle, the steps read 3-6. got rid of my off idle bog too. man, is that nice!!

[1988GTU]

So you just adjusted the "idle" set screw a little bit?

[torq455]

yep, that's all. believe it or not.

[torq455]

well that only worked for a few days. i've since taken the UIM off to do a WOT throttle stop adjustment, new water pump, and better intake snorkel. now it's much worse. started, chugged worse and longer than before. revved it up and held, cleared out and ran ok. got about 125 degs in it, shut it off. wouldn't start. had to put it to the floor to get it to run. then it was so rich it'd barely run. when it did start to smooth out finally, i couldn't rev it up or it'd just stumble and chug. once fully warm it was ok. also, restarting when warm is ok except it revs up like it's cold, you know, it'd go to about 1800rpm then slowly drop down to around 1200rpm. usually it'd just rev quickly and drop down close to it's normal idle. i'm beginning to think it's a bad computer getting worse.

[85_305]

Hey I have the same problem in my '91! Any ideas? I bought it like that, then I fixed it somehow, now since Ive been having a few problems that damn thing is back! It almost dies (or sometimes does) when I initially hit it from a stop. man it's frusterating! Though, a mechanic has told me the TPS is shot. I dunno if he's lying or what?

[z34phoenix]

eh.... the smake reminded me of what i just fixed on my monte.... i have a ported upper lower and TB the vac was enought to suck a considerable amount of oil thru the PCV valve and into the manifold. i just made and installed an oil catch can to collect and separate this oil. it hasnt even been a full day yet and i can see i no longer put out a big puff of smoke at startup.

in your case i think its something else... if it were a vac leak, you would run on the lean side. im assuming there arent any eninge codes. what year car is this? obd1 or 2? might be a long shot, but have you pulled the Idle air control valve out of the TB? it that TB was ported im wondering if the iac has a good seal?