Hello, new to the forum, 5 year Cadillac owner - 1995 Sedan Deville 4.9.
Been hanging out at another Cadillac site, but the attendance seemed weak there and I had to jump ship.
I have been having intermittent starting troubles. When a no-start occurs, there is no fuel pressure at the check valve (the tire-like valve near the fuel line under the hood). If I put a test light on the connection for the fuel pump relay (with the relay removed) I get a momentary signal once the key is turned to the “on” position - like I should. If I put the relay back in and disconnect the fuel filter NO fuel comes out during this momentary signal. If I remove the horn relay and the fuel pump relay and jumper some power from the horn terminals to the fuel pump, the pump will power up and push fuel. With the fuel filter re-connected and the jumper in place, the car will start and run properly. I can quickly remove the jumper and reinsert the fuel pump relay and the car runs just fine and will shut off with the key and even restart properly (sometimes) and then it’s back to not starting. The jumper trick will bring it back to life, but it may act normal for days/weeks or not start the next time it is attempted. At least the recently discovered jumper trick avoids a tow - I've had it towed for this problem twice in the last few months!
Any ideas here? I think the trouble must be upstream from the relay or the jumper trick would not work. Thanks in advance!
PS: I have changed the fuel filter (just in case) and tried starting the car during a "no-start" moment with the gas cap off. I have also swapped relays around to no avail.
Ride On,
Noel
Been hanging out at another Cadillac site, but the attendance seemed weak there and I had to jump ship.
I have been having intermittent starting troubles. When a no-start occurs, there is no fuel pressure at the check valve (the tire-like valve near the fuel line under the hood). If I put a test light on the connection for the fuel pump relay (with the relay removed) I get a momentary signal once the key is turned to the “on” position - like I should. If I put the relay back in and disconnect the fuel filter NO fuel comes out during this momentary signal. If I remove the horn relay and the fuel pump relay and jumper some power from the horn terminals to the fuel pump, the pump will power up and push fuel. With the fuel filter re-connected and the jumper in place, the car will start and run properly. I can quickly remove the jumper and reinsert the fuel pump relay and the car runs just fine and will shut off with the key and even restart properly (sometimes) and then it’s back to not starting. The jumper trick will bring it back to life, but it may act normal for days/weeks or not start the next time it is attempted. At least the recently discovered jumper trick avoids a tow - I've had it towed for this problem twice in the last few months!
Any ideas here? I think the trouble must be upstream from the relay or the jumper trick would not work. Thanks in advance!
PS: I have changed the fuel filter (just in case) and tried starting the car during a "no-start" moment with the gas cap off. I have also swapped relays around to no avail.
Ride On,
Noel