I have a 92 Camaro RS 305 tbi. I have done many mods with the car running fine after each one. A while back I installed some Hedman Shorties on it and just unplugged the O2 and sat it to the side until I could get a bung welded on later. Of course it runs rich for this period of time because the ecm is getting a lean signal. So the time comes to weld a bung on and I go buy a new O2 and install it. So its running fine for a while and then I notice something when im at idle. It feels almost like a miss or a slight hesitation. Now, a month later, it is so bad that my car is dieing at lights and im running rich, really rich. Im going through tanks like crazy. BTW, I already rebuilt the TBI unit with new gasket and o ring kit, cleaned the IAC like everyone said to and checked my MAP, TPS and a number of other things. What is going on??!! Any help would be appreciated.

 

Have you checked for vacuum leaks or exhaust leaks before the 02 sensor?

 

Im almost positive all the vaaccuum lines are good from what ive inspected. and the only place there would be an exhaust leak would be the header gasket and its not leaking i would hear that. Also if it were a vacuum line wouldnt it constantly idle bad instead of up and down?

 

Not always. I had an internal vacuum leak that caused the car to surge all over the place. Took me weeks to find it.

Even with headers your car can still run a bit rich and have a slight surge. The stock tune is off now becuase of the massive VE change. Do you have access to a lap top to do some data logging?

 

Yeah Ive already done some datalogging but, to be honest Im not quite sure what it all means. MAYBE YOU CAN HELP.

 

Now you are on the right track Take a look at the DIY PROM board allong with some of the explanations and discussions in the TBI stickies. The DIY board should tell you what you are looking for after a bit of reading.

 

greg

I did a 89 TBI conversion in my older trans am and it did alot what yours is doing, mine started out as anything over 1/2 throttle it would fall on it's face and get beat by aerostars, then it got worse to where it would die and throw a lean 02 signal and at say 2000rpm in nuetral the entire exhuast from the cat back would glow, I tried everything and it turned out to be the rubber hose between the fuel pump and the metal line on the sending unit had a small slit in it, now after its been replaced it run very nice