Please help
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
From: Welch West Virginia
Please help
My 87 C4 with the 5.7 and 4+3 is really hard to start. New wires and plugs, cap button, pickup coil, ignition module, fuel pressure good. Car just cranks and cranks and finally if I don’t run battery down it will start. Runs fine when you get it going. I hope someone else has had this problem and can help. Thanks
Thread Starter
Cruising
Joined: Apr 2009
Posts: 13
Likes: 0
From: Welch West Virginia
Changed the injector, still cranks and cranks before starting. Was told it could be the key, don’t really know what that has to do with it. I thought if the key diode was bad it wouldn’t crank at all.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
I WONDER if you have a fuel pressure issue. Lack of good fuel pressure...or it goes up to the required pressure but it falls down really fast.
Check you fuel pressure.....or you could have water in the gas tank also....so check fuel quality.
DUB
Check you fuel pressure.....or you could have water in the gas tank also....so check fuel quality.
DUB
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
Connect a fuel;pressure gauge to the test fitting on the right side fuel rail.
Turn your key on but DO NOT try to start the car and what your fuel pressure reading.
You should go up to near 40 psi and HOLD. If it only goes up to lets say 20 psi and holds. Then turn the key OFF and wait about 30 seconds and do it again and see if the pressure climbs up to 40psi-ish.
IF the pressure goes up but falls really fast. There is your problem. You either have a bad check valve in your fuel pump....or the hose from the fuel pump to the sending unit has a hole in it....or you have an injector that is hung OPEN adn not allowing the fuel pressure to hold.
DUB
Turn your key on but DO NOT try to start the car and what your fuel pressure reading.
You should go up to near 40 psi and HOLD. If it only goes up to lets say 20 psi and holds. Then turn the key OFF and wait about 30 seconds and do it again and see if the pressure climbs up to 40psi-ish.
IF the pressure goes up but falls really fast. There is your problem. You either have a bad check valve in your fuel pump....or the hose from the fuel pump to the sending unit has a hole in it....or you have an injector that is hung OPEN adn not allowing the fuel pressure to hold.
DUB
