Hey there, I finally found out what makes my car quit idiling when its warmed up, its my hypertech thermomaster fuel chip, its part number 11182, made for the 82 Z28 5.0 litre crossfire, (EXACTLY WHAT I HAVE). I popped it in, and I LOVE the performance increase, it is unreal what diff on hesitation, etc. But I started driving it, and after about 25 min of driving, it wont idle and the car turns off, my temp NEVER goes past 140, and i have the Powerstat 160 degree thermo in it, this doesnt make sense, it works GREAT until you drive it for a while, then for no reason it will cut off, I know its the chip because i popped my stock one back in and it works great at hours of driving, but I cannot stand going back to this stock chip, not after seeing what this new one could do, so ANY ideas why that chip is causing it? That is the correct chip for my car, it just doesnt make sense, all of a sudden it changes the fuel pressure going in the TBI's and starves the engine of gas, let me know ANY info you can, this is really weird, but I would like to get this chip working, so please, even if a couple people posts, dont hesitate to put your word in, I will really appreciate it, and check couple times daily of new posts, thanks again guys!

nate
82 Z
Edelbrock TES headers
Flowmaster Exhaust
K&N AIR FILTERS
160 Degree powerstat
Hypertech Fuel Chip 11182
etc etc

 

Sounds like the fuel cut off oil presure sending unit is dirty or bad. If they had one in 82? Usually the only thing the comp controls with the fuel pump is the prime when you first start it.

[This message has been edited by 87Z-ya (edited February 19, 2001).]

 

here's my word

CARBURETOR

 

How do you know that the coolant never got above 140*F? Was this by a scan tool reading the CTS or was this by a temperature guage?

The effects of the CTS has a profound effect on the computer controlled EFI cars work. If you engine is indeed thinking that it is only operating at 140*F, then you engine will be thinking it is in "startup mode".

As for the Hypertech eprom, it sounds like you probably needed more fuel. Unfortunately, there is very limited information on the Cross-fire system and I can't offer any suggestions regarding a "custom eprom".

Sad to say, but many people with Cross-Fire do go to other induction systems (carb or tpi) just because of the very limited modifications (and eprom knowledge) of the CF system. Grumpy has done a fair amount of work on CF. He would be the person I would seek advice from if you wish to retain your CF system.