Re: 92 Z NIGHTMARE
 

I don't get the Vacuum reading either maybe just an extra parameter that me scanner has for a sensor the car doesn't have. Ill try bumping the TPS up some and see if that helps It will run up till 7k. Just stumbles/hesitates when first getting on it and happens with every gear shift.

Re: 92 Z NIGHTMARE
 

No luck after bumping the tps up to .56

Re: 92 Z NIGHTMARE
 

Did you check to make sure the secondary map sensor under the ECM is hooked up?????

Re: 92 Z NIGHTMARE
 

The FSM shows that the sensor under the ECM is the secondary port throttle vacuum sensor. It monitors how much vacuum is applied to the secondary actuators. I don't think that would be an issue here unless it is a source of a vacuum leak. A failure of this sensor should set a code 56.

Re: 92 Z NIGHTMARE
 

Vettetech1, Have all the fuel injectors been replaced? Especially the primaries. As Paul says above, they need to be checked while hot. They will read between 12 and 13 ohms cold but lower than that when hot. My car had 4 bad injectors on the secondaries and 1 on the primaries. My symptoms were.. stable idle in open loop then miss fire and sag when in closed loop. Of course closed loop is when the engine temp is up and the O2's are providing feedback to the ECM. So when the injectors started to fail I could see this using TTS datamaster and laptop as the fuel trim went nuts. Something else I had was excessive clutch noise in neutral due to the slight missfire. That all cleared up when I replaced all 16 injectors.

Re: 92 Z NIGHTMARE
 

Over the past 3 years all 16 injectors have been replaced. It came in a few weeks ago running like crap after it was warmed up in power mode. Found 2 bad secondary injectors. After looking at his repair history i noticed there were only 2 more injectors after that were OE. So i suggested we do the last 4 injectors so we wouldn't go through this next year. After doing the injectors it ran great on the test drive. No hesitation or anything. Owner picked up the car a few weeks later and boom running like crap again. Tested injectors both hot and cold are around 12 ohms.

Re: 92 Z NIGHTMARE
 

Were the injectors new or rebuilt?

To my understanding rebuild will.bb fail again eventually.

Re: 92 Z NIGHTMARE
 

deleted for new thread

Re: 92 Z NIGHTMARE
 

Well just got a chance to take it out on the road. Even tho there is a stumble sitting in neutral, you cant notice it while driving it on the road. Maybe I'm just being to critical of it in the bay.

Re: 92 Z NIGHTMARE
 

they were new