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the other day my 91 died at a stop sign, would crank start then die. let sit for a bit started up got about 25 feet then died. after that it would still crank but never fired again. fuel pump can't be heard priming. is it my fuel pump? relay? pressure regulator?
the other day my 91 died at a stop sign, would crank start then die. let sit for a bit started up got about 25 feet then died. after that it would still crank but never fired again. fuel pump can't be heard priming. is it my fuel pump? relay? pressure regulator?
If you can't hear the pump, then it is usually the pump or the relay. Get a voltmeter, and take the gas lid assembly off. Carefully (use plastic putty knives) remove the rubber boot which will let you get to the fuel sender. Use the voltmeter to check if you have power at the connector. There should be three wires, one indicates fuel level, the other are power and ground. Measure volts from power to ground (you don't need to use the connector's ground, you can just measure to the top of the sender if that's easier. You should get ~12 volts after the key comes on (the prime). If you have power at the sender, the relay is good, the pump is suspect. If no power at the pump, relay is suspect.
Last edited by TheBlaster9001; Jun 25, 2018 at 03:29 PM.
The Blaster is correct in diagnosing the electrical, but you may first want to put a pressure tester on the schrader valve on the fuel rail. If there is no pressure then you know that your fuel pump is a problem. Then to be sure, double check the electrical as the Blaster suggest.
Just buy a stock replacement and keep it easy. There is no need to spend extra money (and possibility of a mis fit) on a hi performance unit.
Just went out and the dam thing fired right up ran a little rough. now what do I look for?
My '88 died coming out of Home Depot. Had it towed to a good shop, but it had to sit there over Memorial weekend. They didn't call, so i
called them. They said there wasn't anything wrong with it. Scanned it and highway test drive all checked out. That session cost a whole
$27.00. Lost confidence in the car because nothing checked bad. I scanned it at home also. The car computer doesn't check the fuel
pump operations and since it is 30 years old i replaced it. Pretty simple job. Got an AC Delco stock unit and gasket and strainer for about
$80.00 from Rock Auto.
Just did mine this weekend. Changed the fuel filter while I was at it. That was more of a pain than the pump. But neither is really hard.
I was most suprised by the tank seal prices. They run the gambit from 12 to 47 here. So shop a bit for price on that. I used the Delphi pump. Came with everything needed to replace it and eliminate the pulsator/dampner thing.
Mine wasn't showing any symptoms but getting noisy.
Last edited by belairbrian; Jun 25, 2018 at 08:32 PM.
My '88 died coming out of Home Depot. Had it towed to a good shop, but it had to sit there over Memorial weekend. They didn't call, so i
called them. They said there wasn't anything wrong with it. Scanned it and highway test drive all checked out. That session cost a whole
$27.00. Lost confidence in the car because nothing checked bad. I scanned it at home also. The car computer doesn't check the fuel
pump operations and since it is 30 years old i replaced it. Pretty simple job. Got an AC Delco stock unit and gasket and strainer for about
$80.00 from Rock Auto.
Something similar happened to me a while back. It turned out that I needed fuel. The gas gauge broke and was going down very slowly. Since I don't drive the car on a regular basis I never gave much thought to how much fuel was in the tank. The gauge had never given me a problem before. Now when I get to half a tank I fill up. I'm usually around a quarter tank.
Just did mine this weekend. Changed the fuel filter while I was at it. That was more of a pain than the pump. But neither is really hard.
I was most suprised by the tank seal prices. They run the gambit from 12 to 47 here. So shop a bit for price on that. I used the Delphi pump. Came with everything needed to replace it and eliminate the pulsator/dampner thing.
Mine wasn't showing any symptoms but getting noisy.
I'm glad GM did something we can replace. Did an antenna 2 months ago and that wasn't fun. At a car show someone told me that the pumps develop a
bad spot or a spec of dirt and just need to be jarred to clear up. These pumps were used in many GM cars. Corvette is the easiest to change.
First thing to check that you can is the fuel pressure. Check it at "key on engine off" and see what it does, turn key off and see if it holds. If that passes, see what it does at WOT. Next thing to check is the spark. Do it in cold and hot. See if there is a blue flame. If there is, are the plugs good? If not, replace. Also run the car in a dark garage when cold and spray a fine mist of water around the wires and see if they leak. If not, repeat test with hot motor. Till it happens again, there is nothing you can do except throw parts at it. Carry a spare spark plug and fuel pressure tester. For all we know, it might be the ignition module but you can't test that and bank on the answers. If the module tests bad, it is bad. If not, it may be good but fail in hot. Ask me how I know.
First thing to check that you can is the fuel pressure. Check it at "key on engine off" and see what it does, turn key off and see if it holds. If that passes, see what it does at WOT. Next thing to check is the spark. Do it in cold and hot. See if there is a blue flame. If there is, are the plugs good? If not, replace. Also run the car in a dark garage when cold and spray a fine mist of water around the wires and see if they leak. If not, repeat test with hot motor. Till it happens again, there is nothing you can do except throw parts at it. Carry a spare spark plug and fuel pressure tester. For all we know, it might be the ignition module but you can't test that and bank on the answers. If the module tests bad, it is bad. If not, it may be good but fail in hot. Ask me how I know.
Car runs fine. Can't get it to stumble or miss. Will leave it alone for now. Thanks for the info.
Replaced the fuel pump, and strainer. what pressure should i be getting?new pressure test gauge connected to schrader valve cold no start just key on I get 40 psi after start it drops to 36 and stays there. shut off it doesn't bleed down. fuel filter is next runs like **** but doesn't die on me
Replaced the fuel pump, and strainer. what pressure should i be getting?new pressure test gauge connected to schrader valve cold no start just key on I get 40 psi after start it drops to 36 and stays there. shut off it doesn't bleed down. fuel filter is next runs like **** but doesn't die on me
36 is a tad low, but it should run ok like that. Filter is a good next step.
Replaced the fuel pump, and strainer. what pressure should i be getting?new pressure test gauge connected to schrader valve cold no start just key on I get 40 psi after start it drops to 36 and stays there. shut off it doesn't bleed down. fuel filter is next runs like **** but doesn't die on me
Got to do filter along with pump, in case a clogged filter ruined it. Cheap insurance. I have seen the old sock go into the filter in a pic somewhere so if your sock was original and missing, it is probably in there. Here is mine, I bought new parts and pieced them,
fuel pump?
