RedFirebird

Well i have been having a problem with my GTA getting BAD gas mileage (15 and under) and running poorly. The car has fresh tuneup parts and i converted it to a 3-wire heated O2 sensor. The injectors are also new. I originally thought that this was just due to age and the miles on the engine but i ran a compression check and all cylinders were at 170-180 psi so i don't think its that. I've tried using an Autoxray and all the sensors seem to be fine and the ecm is going into closed loop. Now the block learn and integrator values are all in an acceptable range EXCEPT for idle in which the BLMs are constantly at 150-155. The vacuum is fine (18 in Hg) so i don't think its a vacuum leak. Another thing is then when its idling the exhaust smells strongly of gas and there are black carbon deposits in my exhaust tips, which makes me think the computer is over compensating or something is causing a false lean condition. I do a lot of stop-and-go kind of driving but i wouldn't think a rich idle alone would cause me to get such crappy gas mileage. Someone suggested that i might have low fuel pressure. I don't really know how that would cause the aforementioned problems. I'm really puzzled and right now this is the only car i have to get around in (other car is getting a new motor) and i have to get it smogged soon. Any advice would be greatly appreciated *cough* Vader *cough*

Swapmaster

Pull the vacuum line off the fuel pressure regulator and have
someone turn the ignition to the start position but don't start it.
See if fuel comes out of the regulator vacuum nipple. If not, go
ahead and start the car and make sure you have vacuum on the
plastic vacuum line.

Check that first and post your results.

craiger

BLM.s above 128 are lean values & below 128 are rich.

Swapmaster

Opps. Forget my test. Momentary laps.
Do an injector leak test. Is it an MAF car or SD car?

RedFirebird

It is an '88 350 TPI motor so its MAF. I tried the test with the regulator but no gas came out. I pulled a plug and it had a lot of carbon on it for a new plug which definatley means its running very rich. The injectors are new so i wouldn't think they would be leaking already and i'd think that would bring the BLM's down if anything. Right now its on the verge of throwing a code 44 everytime i sit at a stoplight. I'm going to borrow a fuel pressure guage tomorrow and check the fuel pressure and so forth.

Swapmaster

Did you check to make sure you had vacuum at the regulator.
Also look at the TPS reading with the X-ray, with the throttle
closed it should be about 5.5 to 5.7 volts.