(I know this is a second gen site and my car is 3rd gen, but i really need help-thanks!)

87 camaro iroc-z
305 tpi 5.0L


We rebuild the transmission (T5) and put it back in. Then, when we went to start the car it would turn over, fire maybe 4-8 times and would die. We've checked fuel pressure both at the "on" position and during cranking and according to the shop manual it is ok. We've done the test with a wire in the diagnostic connector and it keeps flashing 12. We then unplugged sensors to test the ECM and it still only flashed 12. So, we replaced the ECM and tried again. Nothing changed. We've checked the starter- working and properly grounded. We've also checked most of the circuits- all working properly. We checked the cold start valve- works (injector light stayed on when plugged into it during crank).
When we went to check the fuel injectors with a test light, it would not flash. This is (according to the shop manual) supposed to flash a code error, and it isn't. We also checked the circuits for the fuel injector system- they work properly and are grounded correctly. The spark plugs fire properly.

We think the ECM isn't sending a signal to the fuel injectors.

Here's what we have tried already per the shop manual:

Diagnostic circuit checked: ok
Tested power to pins in ECM connector and ground to ECM connector: ok
fuel injector circuit tested: ok
injector noid light doen't light during crank
"fuel diagnosis" tests fuel pressure: ok (pressure equals 46- drops to 43)
crank fuse: ok
cold start valve: ok (lights when noid is attached)

When we unplug sensors (MAF, cold start) the ECM doesn't generate error codes (according to the service engine light flash test)- we only get code 12 over and over. We just replaced the ECM, however, and the results didn't change. We think teh problem is with the ECM generating the signal to the fuel injectors, but we don't know how to check on this (manual just says replace ECM).
For the injectors to fire, certain checks are done by the ECM:

pulse from distributor
throttle position
coolant temperature

These are the only test that we know of. If anyone knows of the other checks done by the ECM, that knowledge would be helpful too.

Thanks for the time and help with my problem!

I had a similar sounding problem with my Berlinetta. It would'nt stay running at idle for very long, but would run ok while driving. The idle control valve had a layer of carbon on it. After I cleaned it with carb cleaner and reset/re-installed it the car ran perfect.



[This message has been edited by sikzdrivr (edited January 16, 2005).]

Thanks for the tip, but we can't get it to start at all. Will keep it in mind though.

<font face="Arial,Verdana" size="2">Originally posted by link7211:
Thanks for the tip, but we can't get it to start at all. Will keep it in mind though.</font>

An idle control valve can also prevent your car from starting if its in bad enough condition.



[This message has been edited by sikzdrivr (edited January 16, 2005).]

We don't have a tool (socket or wrench) on hand that is big enough to take the valve out, but we will try to get one soon.

We also changed all of the plugs and found a coolant sensor to the engine block unplugged, but it still won't fire correctly (same crank/firing problem, almost worse).

The plugs we took off of the car had a tiny nub on them that was in the gap (burns hotter, maybe?). The ones we used to replace them were flat there, like a generic spark plug.

Thanks again sikzdrivr for your advice. Hopefully I can try it within a few days.

This car ran fine prior to rebuilding the transmission? Are there any sensors under the car that may not have been connected correctly during transmission install? Just fishing here as I don't know how installing a transmission can make an engine puke?

So far all of the different sensors we have come across have been connected correctly. I keep checking for more sensors on the underside of the car, but I haven't found anymore. Thanks for the tip though.

Most likely your ignition gets power straight from the starter during starting and through the ignition switch after that. Sounds like you may be losing ignition through the switch when you go from START to ON.

------------------
74LT 350/4spd Midnight blue metallic w/black interior
Girlfriends are better than wives.

Is you're battery putting out enought juice to crank and start the car?? I know starting the Harley it will ignight when I lift my finger off the start switch.

We were getting enough juice, although at times it was questionable. we had to recharge it a couple of times. Thanks, though.

Thanks for all of the tips and support. As it turns out, when we took off the distributor cap we found the four-way connector unplugged. Sorry I didn't check for something that simple before, but I thought it wouldn't fire with any wires unplugged. Thanks again for the help though!

PS: Tranny runs sweet now!