MMSuperFan
06-08-2005, 02:53 PM
My '03 has approximately 42K miles on it. 18k with the Trilogy kit. Several months ago, I began to have an intermitant problem with stalling immediately after startup. I went through the normal operator maintenance checks, fuel filter (installed a larger filter eventually), checked MAF, looked for vacuum leaks, checked the intake for leaks, took it to the dealer. All of which proved useless, but the problem did not repeat itself for some time, so no one had any ideas on what could be wrong. I finally added one of DR's dual Cobra Pump setups, in the hope that this might cure the problem. It did help stabilize my rail pressure, but as you read on, this was a different problem.
I took the car on a 2200 mile round trip, 1100 one way, no problems. After arriving at my destination, on a very hot day, the car stalled and refused to start. After having it towed, (BTW cooling down) the car started and ran normally. Returned to Texas, no problems. The next day, the alternator light came on. Had the alternator checked and it was gone. Replaced the alternator, but the car would only run about 3 to 7 miles and shutdown, stalling the same as before. Had the PCM checked, it was bad, after replacing the PCM, the stalling was not fixed, the alternator light went out for the first time in a week, but it would only run a few miles and shutdown.
After a considerable amount of head scratching by two different dealers, my favorite mechanic and eveyone else I could call or PM for information, we began datalogging the few miles we could drive before shutdown. Took several attempts but we finally noticed that the fuel rail pressure would stay around 42 to 48 when the car was running fine, then drop to around 21.5 and immediately (less the 1/2 second later) jump to 74 PSI, followed by an engine shutdown. My dual Cobra fuel pumps are damn good, but not that good, not enough to increase by 50+ PSI in just tenths of a second.
Once my mechanic saw this result, he checked the Fuel Pressure Regulator, determined it was bad and replaced it. Problem solved.
Just hope of you guys have to experience this kind of frustration with diagnosing any problems similar to this. I realize that the electrical problems probably complicated tracking down the real issue, but it was an extremely tense week while my MM was undergoing repairs.
Ron
I took the car on a 2200 mile round trip, 1100 one way, no problems. After arriving at my destination, on a very hot day, the car stalled and refused to start. After having it towed, (BTW cooling down) the car started and ran normally. Returned to Texas, no problems. The next day, the alternator light came on. Had the alternator checked and it was gone. Replaced the alternator, but the car would only run about 3 to 7 miles and shutdown, stalling the same as before. Had the PCM checked, it was bad, after replacing the PCM, the stalling was not fixed, the alternator light went out for the first time in a week, but it would only run a few miles and shutdown.
After a considerable amount of head scratching by two different dealers, my favorite mechanic and eveyone else I could call or PM for information, we began datalogging the few miles we could drive before shutdown. Took several attempts but we finally noticed that the fuel rail pressure would stay around 42 to 48 when the car was running fine, then drop to around 21.5 and immediately (less the 1/2 second later) jump to 74 PSI, followed by an engine shutdown. My dual Cobra fuel pumps are damn good, but not that good, not enough to increase by 50+ PSI in just tenths of a second.
Once my mechanic saw this result, he checked the Fuel Pressure Regulator, determined it was bad and replaced it. Problem solved.
Just hope of you guys have to experience this kind of frustration with diagnosing any problems similar to this. I realize that the electrical problems probably complicated tracking down the real issue, but it was an extremely tense week while my MM was undergoing repairs.
Ron