fuel pump question
Thread Starter
4th Gear
Joined: Jul 2005
Posts: 4
Likes: 0
fuel pump question
1987 manual trans, convertable, 103000 miles.
when I shut vette off, the fuel pump keeps running. Is this normal and if so how long should it run?
What would cause hard starting? Vette takes 15 to 20 seconds to start.
Is this a fuel pump problem also?
thanks!
Yup, it was the relay, thanks for the help! Starts right up after replacing the relay.
when I shut vette off, the fuel pump keeps running. Is this normal and if so how long should it run?
What would cause hard starting? Vette takes 15 to 20 seconds to start.
Is this a fuel pump problem also?
thanks!
Yup, it was the relay, thanks for the help! Starts right up after replacing the relay.
Last edited by n9mkf; Sep 26, 2005 at 04:52 PM. Reason: found problem
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Nope-when you shut it off the fuel pump should be off.That said I suspect you might have a fuel pump relay problem because of the slow starting. If it's shot you have to crank the engine until oil pressure reaches about 4 lbs. before it will start. The fuel pump relay is located next to your wiper motor, and if, or when you replace it (about $12.)
inspect the wiring going to it-the wire insulation shrinks back from heat
and can cause exposed wires to touch one an other. Ask me how I know.
inspect the wiring going to it-the wire insulation shrinks back from heat
and can cause exposed wires to touch one an other. Ask me how I know.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The fuel pump receives current from two parallel circuits. One is the fuel pump relay, which should be disconnected by the ECM when the ignition is turned off. The other is the oil pressure switch which should shut off the pump when the oil pressure drops below 4#. One or the other could be sticking. A little trouble shooting should reveal the culprit.
Hard starting could be any number of items. Often it is caused by the fuel pressure dropping off and you having to wait for it to re prime itself. Some times the injectors leak, which both drains the fuel rails and floods the engine at the same time. It is also possible for it to be a fuel pump relay. But if the relay won't engage to run the pump at start up, it's not likely that it is sticking on, to keep the pump running when it shouldn't.
It's time to become a detective.
RACE ON!!!
Hard starting could be any number of items. Often it is caused by the fuel pressure dropping off and you having to wait for it to re prime itself. Some times the injectors leak, which both drains the fuel rails and floods the engine at the same time. It is also possible for it to be a fuel pump relay. But if the relay won't engage to run the pump at start up, it's not likely that it is sticking on, to keep the pump running when it shouldn't.
It's time to become a detective.
RACE ON!!!
