1986 conv. with a no start problem
Thread Starter
Intermediate
Joined: Sep 2011
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From: Milford CT
1986 conv. with a no start problem
I am in the process of trying to evaluate what my problem is . At first I suspected the fuel pump. I did a continuity check and that checked ok, could the pump still be bad. I also learned that the oil pressure switch could be bad, but I cannot locate it.
Any help would be greatly appreciated.
THANKS
Rich
Any help would be greatly appreciated.
THANKS
Rich
Advanced
Joined: Apr 2015
Posts: 62
Likes: 6
I am in the process of trying to evaluate what my problem is . At first I suspected the fuel pump. I did a continuity check and that checked ok, could the pump still be bad. I also learned that the oil pressure switch could be bad, but I cannot locate it.
Any help would be greatly appreciated.
THANKS
Rich
Any help would be greatly appreciated.
THANKS
Rich
(my pump was bad, that was only one of my problems)
https://www.corvetteforum.com/forums...post1590201018
I recommend checking fuel pump pressure @ the rail. If it is 40# it is not the fuel pump.
If no fuel pressure install the jumper to turn the fuel pump on. and check.. and so on...
Good luck.. keep us posted.
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Race Director
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there you go check the fuse first then go for the pump very easy on the vette. change your fuel filter and flush the lines. easyer to pull the filter from the top. 
might want to check your relay too
I believe your oil pressure switch is by your distributer
might want to check your relay too
I believe your oil pressure switch is by your distributer
Last edited by antfarmer2; Sep 13, 2015 at 09:54 AM.
Thread Starter
Intermediate
Joined: Sep 2011
Posts: 34
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From: Milford CT
The fuse appears to be good. When I crank the motor over with the test light connected to the relay the light stays lit. Does this mean that the oil pressure switch is good. Also I did a continuity check on the pump, the check was ok, can the pump still be bad?
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Race Director
Joined: Apr 2002
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From: Anaheim CA
This diagram of a 1986 fuel pump system might help:
You should be able to get the fuel pump to run by unplugging the oil pressure switch and jumpering across the contact pins in the connector.
The oil pressure switch has orange and red wires coming out of the connector. It is located on the back of the engine behind the distributor:
You should be able to get the fuel pump to run by unplugging the oil pressure switch and jumpering across the contact pins in the connector.
The oil pressure switch has orange and red wires coming out of the connector. It is located on the back of the engine behind the distributor:
Thread Starter
Intermediate
Joined: Sep 2011
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From: Milford CT
I have taken the fuel pump unit out of the car, removed the pump from the unit hooked up dir to battery and it works. I then put the pump back in the unit plugged it in, still out of tank and turned on key, it works sometimes. I could try 3 or 4 times and it will not work, then it will work 3times then not work. Is my key bad ? Is my key switch bad? Or is the vats acting up.
Thanks for all the help.
Rich
Thanks for all the help.
Rich
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From: Anaheim CA
VATS has nothing to do with the fuel pump in your year. With your symptoms I would suspect a bad connection somewhere. Another possibility is a bad fuel pump relay.
See post #11 for a suggestion on how to force the fuel pump to run (short the oil pressure switch connector pins together). That should allow you to troubleshoot without having to turn the ignition on and off over and over.
See post #11 for a suggestion on how to force the fuel pump to run (short the oil pressure switch connector pins together). That should allow you to troubleshoot without having to turn the ignition on and off over and over.
Advanced
Joined: Apr 2015
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VATS has nothing to do with the fuel pump in your year. With your symptoms I would suspect a bad connection somewhere. Another possibility is a bad fuel pump relay.
See post #11 for a suggestion on how to force the fuel pump to run (short the oil pressure switch connector pins together). That should allow you to troubleshoot without having to turn the ignition on and off over and over.
See post #11 for a suggestion on how to force the fuel pump to run (short the oil pressure switch connector pins together). That should allow you to troubleshoot without having to turn the ignition on and off over and over.
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The connector at the top of the sending unit is known for poor connections. It's certainly very likely. Maybe a FP relay as just a matter of maintenance and the fact it's an intermittent issue (in the car) BUT I'd think it's NOT an issue and if after the issue at the tank was corrected when "key-on" the pump cycled as it should then that would confirm no issues. Intermittent in the sender when jumped from battery certainly indicates connector at top of sender, the short harness internal from connector at the top to the FP is possible and an easier find than the connector at the top.
Racetronix I believe used to do a connector but I can't find a link to it right now.
This is their complete package including the connector. You might try to call for just the connector OR there may be other sources. I've never looked or needed one.
http://www.racetronix.biz/itemdesc.a...%2DC43&eq=&Tp=
Racetronix I believe used to do a connector but I can't find a link to it right now.
This is their complete package including the connector. You might try to call for just the connector OR there may be other sources. I've never looked or needed one.
http://www.racetronix.biz/itemdesc.a...%2DC43&eq=&Tp=
Last edited by WVZR-1; Sep 15, 2015 at 08:01 AM.
Thread Starter
Intermediate
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From: Milford CT
I have the sending unit out of the tank. I have it plugged in as if it were in the tank. When I turn on the key the pump comes on for 2sec and test light lights for two sec. I can do this 2to3 times and it works then it will not work 2to3 times, and then work again. The connections appear to be ok at this point. I am going to try a new relay first. I will let you know how I make out. I will also install a new pump.
Thanks for the information
Rich
Thanks for the information
Rich
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From: Anaheim CA
Just for reference, the ECM is what turns on the fuel pump relay (and therefore the pump) for 2 seconds at ignition-on. It applies 12 volts to the fuel pump relay. Monitor that voltage to determine if the ECM or the fuel pump relay is at fault.
Thread Starter
Intermediate
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From: Milford CT
Do I have to wait a period of time after I turn the key off to turn back on to check if pump runs. Also I hear a beep 3 times when I turn the key off.What is the beep? Is it the system resetting it self.
Thanks
Rich
Thanks
Rich
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From: Anaheim CA
I don't know about beeps. I don't recall hearing any beeps on my '86 at shutdown.
I shut off the radio and turn off the HVAC so I can hear the fuel pump run. I usually open the rear hatch also.
Last edited by Cliff Harris; Sep 16, 2015 at 11:49 PM.