Some of you may have read my previous post conserning my injectors not firing. I was thinking it was a pcm issue, but after further research, I'm beginning to think sensors. The question I have is which sensors will cause the pcm to not fire the injectors and how do I check them?

93 Formula LT1 a4

 

Anyone?

 

How have you determined that the injectors aren't firing?

 

The only "sensor" that will cause the PCM not to fire ALL the injectors is the optical module in the OptiSpark. If the PCM does not see the low res pulse pattern from the Opti, it shuts down the injectors and the fuel pump. But that's ALL of them, not just a few.

Many of the other sensors affect the pulse width of the injectors, but none of them prevent them from firing. The PCM will shut the injectors down on deceleration, in certain RPM ranges.

If you are referencing a problem you have discussed in another thread, its generally a good idea to include a link to that thread so people can review your problem. With 58,000 members, its not likely that people will remember past posts.

 

Sorry about that Fred. Here's the link to the other thread - http://web.camaross.com/forums/showt...starting+issue
I pulled the rail with everything still hooked up and had a friend turn the engine over. I didn't get any fuel out of any of the injectors.

If the opti is the only thing that will shut them all down, I don't think thats it. I can here the pump come on and I am getting 44 lbs of pressure.

Correct me if I am wrong. If it's not the opti, then next thing to check would be harness and injectors (can't see all 8 going at the same time but you never know). If they check out, the only thing left is pcm right?