Help, no spark or fuel pressure
Thread Starter
Instructor
Joined: Feb 2000
Posts: 246
Likes: 2
From: Philadelphia Pa.
Help, no spark or fuel pressure
I was racing my 86' coupe this weekend and at one point tried to start it and no start. The motor cranked but no start. I noticed it had no fuel pressure on the fuel line guage, and no spark at the wiresor coil. (not even current at the coil or fule pump. One thing I did notice is a blown fuel pump fuse. Replaced the fuse but still nothing. What would shut down both fuel and spark in a 86', VATS? I don't know were the VATS module is located? Any help is greatly appricated.
Thank you,
Joe
Thank you,
Joe
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
When you attempted to crank it again did the engine turn over at all...any noise? If not then I would suspect VATS. Do you have a spare key? You can wait 6 or so minutes and try again. If not VATS then I would think ECM.
Team Owner
Joined: Jan 2003
Posts: 20,332
Likes: 262
From: Summerland B.C. Canada
Vats would dissable the cranking. The blown pump fuse leads me to believe your pump is toast or almost toast. Here is a little help for diagnosing your problems. These are out of my 86 manual.
http://members.shaw.ca/corvette86/En...ButWontRun.pdf
http://members.shaw.ca/corvette86/Ig...System-EST.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/Fu...l%20System.pdf
http://members.shaw.ca/corvette86/En...ButWontRun.pdf
http://members.shaw.ca/corvette86/Ig...System-EST.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/Fu...l%20System.pdf
Thread Starter
Instructor
Joined: Feb 2000
Posts: 246
Likes: 2
From: Philadelphia Pa.
Thanks for the reply. I should mention that the car also has an ACCEL dfi computer piggybacked with the stock computer. The fuel pump is about 1 hour old and works when power is supplied to it. I'm leaning towards an ecm but thought I would get some other opions.
Thanks,
Joe
Thanks,
Joe
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
I reread the first post and it answered my cranking question.
If the engine turns over and just no spark or fuel pressure I would start by testing the wires that run to the distrubitor and fuel pump at the ECM. Perhaps the ECM has lost its ground and just needs to be tightened. It would suck to purchase a rebuilt ECM and install and the same problem. Troubleshoot.....follow Agent86 diagrams for the best advise.
If the engine turns over and just no spark or fuel pressure I would start by testing the wires that run to the distrubitor and fuel pump at the ECM. Perhaps the ECM has lost its ground and just needs to be tightened. It would suck to purchase a rebuilt ECM and install and the same problem. Troubleshoot.....follow Agent86 diagrams for the best advise.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
This is one I'd definetly have the ignition control module checked, as well as checking the resistance of the pickup coil, that you can do, the module can be tested at autozone, sounds like the ECM isn't recieving any signals.
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I'm worried that maybe the piggybacking is causing something, are you sure you have that wired correctly?
Thread Starter
Instructor
Joined: Feb 2000
Posts: 246
Likes: 2
From: Philadelphia Pa.
The piggybacking has been in the car for years, but what I just found out is the ACCEL computer does control the fuel pump and ignition. And the grand kids were jumping around in there (roll bar equals monkey bar) were that computor is located so tonight I'll have to check that wiring.
Joe
Joe