Hi guys I need some help troubleshooting my project. 1996 Camaro 3.8l transplanted into a Porsche 944. Stock motor, Motor harness, ECU and BCU. Motor ran before the transplant. Fuel pressure at rail 45-50 psi during crank. Pulled a plug and verified spark during crank. ECU only says that cooling fan relays are missing which they are. No misfire codes. Voltage ok to injectors. Power at ICU to crank sensor. Crank sensor seems to generate a pulse. I only have a multimeter but I watched the voltage vary from 4 to 6 vdc while cranking so I think it is working. I’ve double checked that plug wires go to the correct cylinders. 2 years since motor ran. New fuel tank and lines but old rail and it had some skanky gas up in the rail so I bled the rail. Fresh gas coming out of pressure test port. I’ve tried tapping on the injector bodies. Could bad gas have glued all 6 injectors shut? I’m stumped.
Got any suggestions?
Did you bypass the VATS system?
A little knowledge is a dangerous thing. Or maybe just annoying. Anyhow, it's why I'm asking whether this is a setup which supplies 12V+ to the injectors to pulse them, or which supplies 12V+ all the time and then provides ground in order to fire them... In which case I wonder whether it could be a ground issue. Apologies if this was all really tested under "voltage ok to injectors."
Could you hook a test light up to an injector plug to see it cycle? Or pull a plug and see whether you've got any gas at all getting injected, manky or otherwise?
You've probably got air, you've got spark, you've got some aspects of fuel while some are questions. If you do have fuel, then I'd wonder about when you're getting spark...
In reply to Patrick :
The BCM is still active and talking to the ECU. The BCM is happy as far as I can tell. I have simulated the key resistor and the fuel pump runs so I know the fuel enable circuit is ok. No mods to ECU program. However I have bypassed the anti theft relay on the start solenoid circuit.
In reply to Ransom :
When I pulled the plug to check for coil spark I noticed that it seemed dry. I don’t know the answer to your question about the injectors are positive or negative switched. It’s a good question. I only know that the injectors are getting 12 to one contact when the key is in run.
I don’t have an led test light. Only an old fashioned bulb test light.
Injectors are hot and the pcm grounds them in a gm. You should grab a noid light to verify injector pulse
Patrick said:
Injectors are hot and the pcm grounds them in a gm. You should grab a noid light to verify injector pulse
Ok I will do that in the morning. Thanks so far.
Patrick said:
Injectors are hot and the pcm grounds them in a gm. You should grab a noid light to verify injector pulse
This, and injectors can stick shut from sitting. If you have an injector pulse then cleaning the injectors is probably a good next step.
Ethanol infused gas can cause weird issues of left to sit and get old.
I’d swap the injectors or build a test/clean rig to see if they can be cleaned and brought back to life again.
Good luck
Will it try to start on starting fluid/ carb cleaner?
stan_d
SuperDork
10/6/18 7:00 a.m.
I have made a test lead and put battery voltage to each injector till it clicked . Just tapping the ground on the negative terminal. I did have the noid light signal frm the computer.
I am out of starting fluid so I wasn’t able to do that test. This morning I will pick up a can along with a noid light. After sleeping on the problem I’m currently thinking that my donor Crammit probably had a combo of wrong passkey and aftermarket bypass so it ran ok. Then I came along and yanked it out, but chucked the bypass module. So the resistor I’m using isn’t what the BCM wants. I have the other values so it won’t be that hard to try swapping them. From what I read it takes the BCM 3 minutes to reset after each wrong value. So for an hour or less of swapage I can find out.
It lit up with starting fluid so we’re down to either stuck injectors or no squirt signal. Stay tuned.
Sparkydog said:
And the winner is.....
Stuck injectors.
That's an easy one to fix. Looking forward to burnout vids!
“On to the next, I’m on to the next one.”
I’ve replaced the injectors and now she runs for 3 seconds and stops. But that’s progress!
Next up is solving why fuel enable doesn’t stay on. Most likely I have anti-theft issues.
Thanks for the help everyone!
