304 EFI not running

[James]

I have set up the check engine light in the dash but don't know how to check codes...how do I check codes?? It was black smoke (yes fuel?).

Fairly happy I have checked the basics... I have the plugs out and have spark at each plug..

The silver box (if you mean the ignition module) has been replaced. I'm wondering how the other sensors effect idling and running i.e. maf, map, tps, and the other one at the throttle body???

[utevanwgn]

I run 2 of these in my Q and Z. The symptom you describe is a usually a coolant temp sensor problem.
Poor or open circuit cts signal will blow black smoke and make it run V poor and foul plugs .
Check the cts connector under the throttle body the one with 2 wires the other does not talk to the pcm.
Can you use a multi meter. If so check the resistance values of the sender both from the wires and from the pins (to find a connector problem ).
Hope this helps

[James]

Thanks heaps for pointing me in the right direction utevanwgn, I found the wires to this temp sensor were brittle and when I played with it a wire had actually broken, fixed it up and it's running sweet. As I said in the first post it would be something I have played with.
I had actually extend the ignition module harness to shift it out the way and thought I had crossed some wires but had checked that about twenty times so needed to check elsewhere.

Thanks again.

[utevanwgn]

Efi problems are 99.9% wiring issues.
Knowing what causes what can be paralleled with conventional systems.
The temp sender has a big role to play with cold start conditions just like a stuck choke therefore the same symptoms.
Glad I could help.