Buick Repair Questions? Ask a Mechanic for Answers ASAP
Don't have a gauge to check with, but when I press the relief valve on the fuel rail it sprays pretty strongly.
Could this be a pressure regulator issue?
As I said, I don't have a fuel gauge to check pressure. When opening the pressure relief valve it seems to have pretty good pressure.
Have tried turning ignition on/off several times to build up pressure to try getting it to start with no luck.
Pressure is fine.
Got a noid light and found out there is NO signal to the injectors. Any suggestions??
All fuses are good.
Injectors are getting an intermittent signal. The noid light shows that the signal is not always there. (not a normal pulsing like I would expect)
Check engine comes on.
Could this be a bad ground somewhere?
Power is constant (although it does vary slightly - 0.04 volts change max )
Will check ground next.
Tried starting fluid again and now there is NO ignition as well as the intermittent injector signal.
Where is the PCM located?
Thanks, XXXXX XXXXX is the ECM located?
Just need to know so I can check the various connections.
So on this particular engine the ECM and PCM are the same unit. Is that correct?
And it is located underneath the air filter box, correct?
Got it out.
Check for a replacement at the auto parts store and found out none of them carry it anymore.
Found a possible used replacement at a salvage yard. The possible replacement is in a 1994 Checy Caprice with an LT1. Should the computer from the Chevy be compatible with the Roadmaster fom the same year (and with the same engine)??
Swapped the ECM still no luck.
Do you have a wiring diagram you could share?
Just checked the ignition system by pulling a plug to check for spark. No ignition spark was noted.
Any suggestions? (Checking grounds now.)
Checked for spark at coil and found no spark.
Igition control module problem???
Thanks Nate, I figured that was the case.
Funny thing is there was spark when the problem first appeared, but when I tried starting fluid again I got nothing. As I said, now there is nothing to the injectors and no coil response.
Based on the diagrams (and some research) I figured it was likely the OptiSpark system.
From my research I found that waterpump failure can cause failure in the optispark system (distributor behind the waterpump). I just bought this car 2 months ago and the guy I bought it from had had the water pump replaced a few months before due to it leaking.
Thanks again, will let you know how that goes. It is going to take a few days because no one carries that part locally anymore.
That's what confused me at first. There was spark but no fuel at fist. Now neithr works correctly.
Thanks again, will let you know how it goes.
Thank you very much. It was definitely the distributor.
She's running fine now. Excellent answers.