Help !!! Running Rich ???

[ams7]

My son and I have a 1978 280z with stock injection. The car has a rebuilt motor (4k miles) has been running great for last year or so but just started running poorly.

For 3 days it would run bad when cold and was running a little rough, then on the 4th day it would barely run at all, back fired, black smoke bucking, and would not idle.

I took it to my local shop (almost had to have it towed) they determined that it was running "pig" rich. They checked the temp sensor and airflow meter and all was working correctly, they are having trouble finding the gremlin (perfect compression too)

 

I told them if Hybrid Z guys cant figure it out no one can!

 

Any help would be great.

 

Thanks Jerry

[stravi757]

Have you looked for any vacuum leaks.

[rossman]

This is a pretty common problem with these cars. and I bet you could figure out the problem.

 

The EFI Bible ( http://www.atlanticz.ca/zclub/techtips/efisystem/280zfuelinjectionbook.pdf ) can help diagnose the problem.

 

Lots of information here too: http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm

 

A quick Google search came up with this: http://www.classiczcars.com/forums/archive/index.php/t-13077.html and this: http://forums.hybridz.org/showthread.php?t=128238

 

Clean all of your FI connectors with a good connector cleaner. Double check that your temp sensor and AFM. My experience is that most regular shops know nothing about these old FI systems.

[ams7]

Thanks I will chek out this info and give it to my machanic