Re:
Thread Starter
Intermediate
Joined: May 2011
Posts: 49
Likes: 0
From: Kansas City Missouri
Re:
OK! I have a 1985 corvette bone stock 160,650 miles it runs good but I cant figure out whats going on. Last summer I noticed that my car would stall at a light when at operating temperature, and will stumble when I give it gas. I also noticed that the fuel pump doesnt run for the 2 seconds it suppose to when I turn the key to the on position.......I know it sounds crazy but the gauge is showing there is no fuel pressure when I turn the key to the on position but it still starts and the pump sounds strong(After 10secs of cranking). I checked the fuel pressure when the car was started and it read 37-38 psi. Could my pump be going bad or am I aiming at the wrong thing?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The ECM turns on the fuel pump relay for 2 seconds when you turn on the ignition. Sounds like that is not happening. Probably a bad relay. They are pretty cheap so it's probably easiest to just replace it. It could be a wiring issue.
If the fuel pump relay fails there is an oil pressure switch backup that turns on the fuel pump when oil pressure reaches 4 PSI.
For the stalling issue do a minimum idle adjustment:
http://forums.corvetteforum.com/1570563689-post1.html
If the fuel pump relay fails there is an oil pressure switch backup that turns on the fuel pump when oil pressure reaches 4 PSI.
For the stalling issue do a minimum idle adjustment:
http://forums.corvetteforum.com/1570563689-post1.html
Thread Starter
Intermediate
Joined: May 2011
Posts: 49
Likes: 0
From: Kansas City Missouri
Re
I just replaced the fuel pump relay and the pump still doesnt come on for two seconds but it still starts and runs. If I gas it from a dead stop or try to do a donut the car stumbles like its thirsty for fuel.???
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Pull out the fuel sender assembly and look inside the tank. There is a plastic tray in the bottom that holds fuel when cornering. The fuel pickup sits inside that tray. If the tray comes loose and moves out of position you can get the stumble when the fuel moves away from the pickup. The tray is glued to the bottom of the tank.
This excellent article by Frizlefrak will show you how to take the fuel sending unit out:
http://forums.corvetteforum.com/c4-t...h-article.html
This excellent article by Frizlefrak will show you how to take the fuel sending unit out:
http://forums.corvetteforum.com/c4-t...h-article.html
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Race Director
Joined: Aug 2007
Posts: 11,889
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From: Whitefish Falls Ontario
St. Jude Donor '08-'09
Here is the drawing for the fuel pump, this is for the start problem, for the stall problem you might want to connect a pressure gauge and tape it to the windshield to check pressure when the problem occurs..
Last edited by ccrazor; Oct 9, 2013 at 02:13 AM.
