Now won't start
Thread Starter
7th Gear
Joined: Jul 2010
Posts: 7
Likes: 0
Now won't start
86 automatic, ran good last week, died on road, had towed home, replaced ign. mod., coil, cap, rotor, fuel filter, fuel pump relay,has good fuel pressure and flow, adjusted TPS, if I hot wire fuel pressure relay, fuel pump will work, if I turn on ignition fuel pump works. Holds fuel pressure for an hour. Good spark. If I try to start it ,it will surge one time but not start, then will just crank and not start. It will run on starting fluid. What's left?
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
86 automatic, ran good last week, died on road, had towed home, replaced ign. mod., coil, cap, rotor, fuel filter, fuel pump relay,has good fuel pressure and flow, adjusted TPS, if I hot wire fuel pressure relay, fuel pump will work, if I turn on ignition fuel pump works. Holds fuel pressure for an hour. Good spark. If I try to start it ,it will surge one time but not start, then will just crank and not start. It will run on starting fluid. What's left?
Thread Starter
7th Gear
Joined: Jul 2010
Posts: 7
Likes: 0
Checked injector pulses
I checked for firing pulses on 4 injectors (the easiest ones to unplug) and got no pulses. Also checked the resistance of those same 4, and resistance is 16.5-16.7 ohms. What is the next step?
Corvette Enthusiast
Joined: Oct 2007
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From: So. Cal.
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Thread Starter
7th Gear
Joined: Jul 2010
Posts: 7
Likes: 0
OK, so if the injectors were to be plugged,that would be the next thing to fix, but how do I get them to pulse? I don't think it's a VATS thing because it will crank and has spark, and the fuel pump relay is working.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You have a fuel delivery problem, starts on starter fluid, no injector pulses. You need to find out why there aren't injector pulses. First check the two injector fuses with an ohmeter, it, "sees", better than you do! 
Injector pulses are triggered by reference pulses from the distributor to the ECM. You likely have reference pulses due to new spark module and good spark. You might have a defective ECM and the only way to find this out is to replace it with a known good one.
Injectors can be removed and tested, but first you have ensure that they are being pulsed before you can suspect them.
Injector pulses are triggered by reference pulses from the distributor to the ECM. You likely have reference pulses due to new spark module and good spark. You might have a defective ECM and the only way to find this out is to replace it with a known good one.Injectors can be removed and tested, but first you have ensure that they are being pulsed before you can suspect them.
Team Owner
Joined: Jan 2003
Posts: 20,297
Likes: 240
From: Summerland B.C. Canada
If both injector fuses test good, you might want to check to see if the 4 pin connector at base of distributor, is clean and tight. The ECM needs to see a reference signal from distributor, before it will fire the injectors. The reference signal wire, is one of those 4 wires.
http://members.shaw.ca/corvette86/En...ButWontRun.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/En...agram%2086.pdf
http://members.shaw.ca/corvette86/En...ButWontRun.pdf
http://members.shaw.ca/corvette86/Fu...mDiagnosis.pdf
http://members.shaw.ca/corvette86/En...agram%2086.pdf
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Thread Starter
7th Gear
Joined: Jul 2010
Posts: 7
Likes: 0
While checking for power to the injectors I found a pinched wire at the distributor 4 pin connection-that was it-it was shorted out preventing the signal from getting to the ECM. Thanks for the help guys. I'm back on the road!
Safety Car
Joined: Mar 2005
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From: Winnipeg Manitoba, Canada
