KYL98

Ive had a re-occuring problem with my 91 Z in that in runs REALLY rich. I have checked all sensors and finally got my laptop online with Craig's ECM852 program. I checked the injectors with a meter at oper. temp, and only two of eight were in spec. The car seems to run ok when first started, but after closed loop, it idles rough and runs really rich. That theory was verified with the laptop....BLM's are stuck at 108(cell 4 mostly) and the INT bounces around....sometimes as low as 94?? I have noticed that the 02 readings bounce around alot also. The only time the BLM and INT achieve 128 is at 75% throttle. Are just my injectors causing something like this???? Ive heard that the Canister Purge can cause this also.....I tried blocking off where it goes into the TB, but the car still ran the same. I also disconnected the 02(thinking I got a bad one) and no change as well. All ignition parts are new, and check out fine. Anything else mechanically that could cause that?? maybe a stuck valve? Or should I just replace the injectors and go from there? My GM tech buddy said if the injectors are reading low resistance they are just spitting fuel not spraying it, causing fuel to just be sort of dumped into the cylinder......I guess that would explain the rich part, right? Sorry this is so long, just wanted to make sure the injectors are at fault before replacing......thanks in advance for any suggestions, comments, etc...

nape

iTrader: (1)

Sounds like you hit the nail on the head to me with the injector diagnosis. My buddy used to have the same problem in his '92 Corsica.

I don't know of a way to check it with software though, using a multimeter is the best way I know.

I'd say grab a set of LS1 take-offs from SLP [only $100], modify the injector constant in TunerPro, and then see how she runs.