Looking for a little tech help from the locals....

[TTA579]

Hi guys, long time no see. TTA579 is running but I'm having a little trouble on startup. I wanted to ask you guys because I know so many of you are particularly knowledgable.

After what I still believe is a difficult start, the car will nearly stall about twice while bringing the idle down from 1500rpm or so. After the car settles on ~800rpm and it's warm it appears to have little to no issues. If I try to put the car in gear before the idle has come down it will stall, after that time however, all is well.

Following the idle adjust procedure, the car takes a long time to settle after adjusting the idle screw, almost to the point of not adjusting. I've settled on an IAC of ~45 for now.

O2 count shows leanish (300) at idle, but rich with any sort of throttle (800). Everything else on the scangauge looks normal (using buick numbers). All parts look stock except for the cat-back.

If you have any idea what's going on here, I'd appreciate the help! Thanks.
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[meanchicken]

Did you reset your TPS adjustment after messing with the IAC?

 

[TTA579]

Yes, I've readjusted the TPS after every IAC adjustment.

 

[BlackBandit]

What do your blm's look like? Could be a lazy IAC motor.

 

[TTA579]

IAC valve is new with a new angle boss. BLM is 121 or so? I'll have to write down some numbers next time.

 

[SPOOLFOOL2]

Start with the easy stuff first. I'd start with looking for vacume leaks. Check ALL the hoses, check valves, vacume block gasket, etc. Any codes on the scanmaster? Has the car been sitting for a while? How do the plugs look?

Mike Barnard

 

[BlackBandit]

vacuum leaks are good to lok for but normally they would result in a higher blm. A leaking injector is also a possibility and maybe a flakey maf.

 

[TTA579]

Thanks for the help, .

A little additional info: all the vacuum lines and check valves have been recently replaced, new billet vacuum block and gasket installed, no scanmaster codes. New MAP. Original and new (used) MAF exhibit the same issues. Fuel Pressure is good and does not drop immediately after shut down. Car was sitting for a couple years before my ownership, but I'm running it weekly trying to troubleshoot. Plugs looked fine when I checked them last, but that may have been a 6-mo to a year ago. New plug wires.

Off topic: Mike how do you get your car to pass CA emissions?

 

[turbolou]

It sounds like an IAC problem or the throttle body is gummed up & not allowing the air to bypass it correctly. is there a rebuilt MAF sensor that has been installed & possibly inferior, wrong or simply bad.

 

[TTA579]

Lou, as I mentioned above, the IAC valve and boss are new. When I installed it, I cleaned out the throttle body very well at the same time. Without a known good MAF to compare mine to, I don't know how to eliminate my MAF. I understand I can't just go buy one because remanufactured models don't work correctly. I suppose I could install a translator and LS1/LT1 MAF.

 

[TTA579]

I don't know if it's relevant or not, but after the car has warmed up some, it will restart flawlessly.

 

[daves87gn]

might want to check for leaking injector

 

[TTA579]

Thanks John, that's on my list of to-dos.

 

[SPOOLFOOL2]

Off topic: Mike how do you get your car to pass CA emissions?

Just got back in town. To answer your question. These cars don't need big cam shafts to run strong. It's all done with boost, timing and "Voodoo". They should burn as clean as butterfly farts, get good gas mileage and pass smog, if in good running order, with a good cat and all the stock stuff on.

That's my story and I'm sticking to it.

Happy spooling.
Mike B.

 

[Drewster]

i would look at the IAC Oring/gaskets or leak check there.

 

[TTA579]

I'm still looking at IAC causes. The IAC count dropped to 0.