I have been fighting this for a week now.
94 z28
6 speed
LT headers
60# injectors
6# vortech
52mm TB
The problem is that at idle the car runs like crap, the BLMs stay at 128 and won't move even though the O2s are showing extremely rich on one side and lean on the other, installed a F.A.S.T dual sensor WB, yesterday and using the analog outputs it still does the same thing. On bank 1 i am running an AFR of 15. roughly, on bank 2 i am running an AFR of 12.2.

I can't find an exhaust leak, i have a miss i can't find, have also checked for an intake leak, is it possible for it to leak on the bottom of the intake only and cause this much problems? The only thing i haven't tried is using a temp gun on the headers to find the missing cylinder.

Any suggestions would be appreciated, especially on why the computer is not even trying to compensate through the BLMs.

 

Does your aftermarket TB have the "bypass" hole like the stock TB to assist the IAC to provide air at idle?

 

More info on split BLMs: http://para.noid.org/~lj/PCM%20Tutor...litBLMinfo.htm

 

But i have a stock cam and the BLMs are not split they won't move from 128 the computer will not even try to move the integrators

 

As for the TB it has been on there a long time even with the vortech and no problems up till about 2 weeks ago, I wouldn't think that would have anything to do with it my IAC is functioning normal and nowhere near pegged.

 

Unplug your injectors on that bank one at a time and if ya don't hear a difference in the running,that's the one.

The O2's can't read raw fuel and if ya got a cyl out are likely to do the lean thing and richen it up.

 

If the BLMs aren't moving from 128 it sounds like you're not going into closed loop mode.

 

Yeah i know but the it is going closed loop and learn is enabled, i already know which cylinder it is, its #7 found it real easy with a temp gun its about 70 degrees colder than the rest, also moved that fuel injector to the passenger side to see if my problem moved and nothing, done a compression check and all of the drivers side has 165. Also changed just that plug wire and nothing has changed, i have come to the conclusion its mechanical so i'm going to pull the intake and see.

 

Before pulling the intake, pull the valve cover and check valve lash on #7 valves.

 

I already took off the intake, well it almost fell off car has never been apart since i've owned it but the drivers side intake bolts where almost loose enough to take off with my fingers. The passenger side was stuck really well it actually ripped the gasket, the drivers side the gasket fell off when i picked it up, and the gasket surfaces where completely soaked it oil. I'm guessing if oil could get that far in so could air.