I bought my 2003 Cobra in late June. About 60k miles. It was running fine for the approximately 10 days of driving it over the course of about a month. The car sat for a week in the garage while I was on vacation. Possibly relevant mods are 2.3 Whipple, 2 LB lower, 3 inch upper, Lund Tune, 60 LB injectors, K&N Cold Air Intake FIPK, an Accufab Throttle Body, a Kenne Bell Boost a Pump. Catless X Pipe, with code for cats turned off in tune. Tuned for 93 octane. Previous owner told me to set the BAP to full rich (50). I apologize for the wall of text, but I really, really do hope someone can help me. I want to give as much detail as I possible can. It's really frustrating owning a car for a few months and having it towed home 3 times.
Timeline:
8/19 - After sitting for a week in the garage, it starts up on the third try.
8/24- On a ~100 mile drive home from a day trip, with a few mild pulls along the way, 90 F outside, the engine starts sputtering, AFR gauge starts shooting up. I manage to get it over to the shoulder of the highway. Jump from "battery jumper" turns the car on, but attempts to pull away result in engine sputtering and dying, multiple times. Jump start from a flatbed will not turn the car on. Just clicks. Car towed home. Battery read 11.99 V. Battery switched out for a battery from a friend's truck, just to test alternator. Car started on truck's battery, but voltage went down. Seemed to be alternator failure.
9/24- After waiting nearly a month for my J2 Fabrication alternator, install alternator, install Big 3 Wire upgrade, install heat shield between alternator and exhaust, install cooling duct to run from front bumper aimed up toward alternator. Startup car via jumper cable, let it idle for a little while, then turn car off. Had no time to drive it.
9/28 -Startup and it runs and drives fine...for 2 blocks. Car sputtered and died again. Jump from friend's car does not work. Only clicks. Installed new Champion 59-590CH battery. Car turned on, but then sputtered and died again. Codes read were for fuel pump and fuel rail pressure sensor. Ordered 2 new fuel rail pressure sensors (1 for backup). Car towed home again.
10/6- Install a new FRPS and a Kenne Bell FRPS disc. Starts on second attempt. 12.5V off, 14.5V running. But then the AFR goes all the way up after about 5 minutes, and the engine sputters and dies. Change out fuel pump fuse under hood for a new one, though the old one was not blown. Same thing occurs. Change FRPS to the second new one. This time, starts and runs for a while, take it out of garage, go about 3/4 down the driveway, and it sputters and dies again. Get it started again, make it around the block, but sputters and dies again in the driveway. Push back into garage. Disconnect MAF connector and blow into the electrical connections. Disconnect IAC connector and blow into the electrical connections. Undo negative terminal on battery and reconnect it. Starts up and runs fine. Take it around the block, then on a short drive around the neighborhood to friends house. Stop inside friend's house for a while. Come back outside, car turns on, but sputters and dies after about a minute. When trying to start it this next time, I listen for the fuel pump this time as I turn the key to accessory on. A few times turning the key with no fuel pump priming sound, but then on the ~4th try, I hear the pump prime, and it starts fine. I drive it straight home to the garage.
10/7- Check 30A fuse in BAP. Looks a little dirty, but not blown. Change it for a fresh fuse. Set key to accessory a number of times, it seems like it is priming the fuel pump every time. Start the car and let it run for a while, about 10 minutes or so. Turn it off and repeat. It stays running each time. Try taking it around the block. Sometimes it sputters under throttle, sometimes it does not. Pull back into garage. Order new fuel filter, and factory style Carter P76130S fuel pump assembly.
10/19- Take down fuel tank, install new fuel filter Motorcraft FG 986B. Old one was very dirty. Attempt to install new fuel pump assembly. The tiny plastic tab on sending unit breaks. Attempt to bond the plastic with JB Weld Plastic Bonder. Leave it to dry overnight. Attempt to install again, the tab breaks again. Try JB Weld Plastic Weld. Leave it to try for about an hour. This time, stick sender "arm" in first, then push the end of it into sending unit. Seems like it held and did not break off. Get everything back together. First time priming the fuel pump it sounded very different. Like a buildup of resistance. Starts up and runs fine for a while. Fuel gauge reads about 1/4, though there is about 1/2 in the tank. Give it a few light revs to about 2000 RPM, but instead of returning to idle of about 800 RPM, it hangs up at 1250-1500 RPM. IAC valve cleaned with 'parts cleaner' and MAF sensor cleaned with MAF cleaner. That was not enough. Throttle cable sprayed with a tiny amount of 'parts cleaner' near the throttle body. That solved the idle issue at the time. Go to fill up gas at nearby station. Tank reads at E even when full. So either the plastic tab broke again in install, the gas melted the Plastic Weld, or the sending unit itself was damaged in install. Whatever, I can deal with using my trip odometer as my means of knowing roughly how much fuel I have left, until it becomes annoying. Do some driving around the neighborhood, no issues.
10/27 - Started up on first try, however fuel pump did not have the same kind of buildup of resistance sound as it did on the first startup with the new pump assembly. Did some errands, started up and ran fine at each stop.
10/28 - Attempt to pull car out of garage to give space to change oil. Car turns over but will not catch. Changed fuel pump fuse under hood to a 30A, according to some recommendations on this forum when running a BAP. Put in new 20A fuses under dash for CCRM and Fuel Pump. Still no luck. Ordered new CCRM.
11/3- Installed new CCRM. Car started right up. Idle a bit high, about 1250 RPM. Turn car off. Oil change for Mobil1 Full Synthetic 5W30, Mobil1 M1-210A Oil Filter. Do a few trips around the block, then a short neighborhood drive. While making one turn in 1st gear, the car sputters. I pull over, and it sputters more and dies. I wait a minute. It starts on the second attempt. I do some more driving in the neighborhood, about 15 minutes worth, then head home. Order new Idle Air Control valve, thinking it may solve high idle RPM. Go back out later to run some errands, no issues.
11/4 - Go for first proper drive on highway. About 2 hours worth of driving, making stops about every 30 minutes to do errands. Starts and runs fine every time. Feels fine at half-3/4 throttle on highway. AFR about 15-16 at idle. On highway AFR shoots up to unreadable after getting off the throttle for a few seconds, then returns to about 14. About 12-13 on heavy but not full throttle. Come home. Let the car rest for about 5 hours, then do another 2 hours of straight highway driving with no problem.
11/7- Run some errands, starts, runs fine. Full throttle all is well.
11/9- 2 hours of straight highway driving, nonstop. Starts, runs fine. All is well.
11/10- I do not hear fuel pump prime. But the car starts and runs fine. 30 minute drive to the day's activity, runs fine, all is well. Car sits for about 3 hours. Go out for a spirited drive for about 15 minutes. I do not hear fuel pump prime. But the car starts and runs fine. Let it warm up for a few minutes. About 10 minutes into the drive, a minute after a 3/4 throttle pull, the car sputters in 3rd gear. I pull over, put it in neutral and it dies. Give it a minute. Start it up again, it's ok. Drive it about another 10 minutes then return to day's activity. Car sits about 3 more hours. Go to leave day's activity, I do not hear fuel pump prime. I let the car warm up for a few minutes in the ~35 F weather. I try to pull away and the car sputters and dies. Service Engine light on dash, with Fuel pump and FRPS codes on my tuner. Change the Idle Air Control Valve for the new one. Doesn't help. Try disconnecting and reconnecting the negative on the battery to reset the IAC valve, doesn't help. Try blowing into MAF, MAF connectors, and IAC connectors. Doesn't help. Try changing all fuses under dash and under hood that are related to fuel pump, CCRM or PCM. Doesn't help. Disconnect and reconnect negative to try to reset what the fuses affect. Doesn't help. Car towed home.
Timeline:
8/19 - After sitting for a week in the garage, it starts up on the third try.
8/24- On a ~100 mile drive home from a day trip, with a few mild pulls along the way, 90 F outside, the engine starts sputtering, AFR gauge starts shooting up. I manage to get it over to the shoulder of the highway. Jump from "battery jumper" turns the car on, but attempts to pull away result in engine sputtering and dying, multiple times. Jump start from a flatbed will not turn the car on. Just clicks. Car towed home. Battery read 11.99 V. Battery switched out for a battery from a friend's truck, just to test alternator. Car started on truck's battery, but voltage went down. Seemed to be alternator failure.
9/24- After waiting nearly a month for my J2 Fabrication alternator, install alternator, install Big 3 Wire upgrade, install heat shield between alternator and exhaust, install cooling duct to run from front bumper aimed up toward alternator. Startup car via jumper cable, let it idle for a little while, then turn car off. Had no time to drive it.
9/28 -Startup and it runs and drives fine...for 2 blocks. Car sputtered and died again. Jump from friend's car does not work. Only clicks. Installed new Champion 59-590CH battery. Car turned on, but then sputtered and died again. Codes read were for fuel pump and fuel rail pressure sensor. Ordered 2 new fuel rail pressure sensors (1 for backup). Car towed home again.
10/6- Install a new FRPS and a Kenne Bell FRPS disc. Starts on second attempt. 12.5V off, 14.5V running. But then the AFR goes all the way up after about 5 minutes, and the engine sputters and dies. Change out fuel pump fuse under hood for a new one, though the old one was not blown. Same thing occurs. Change FRPS to the second new one. This time, starts and runs for a while, take it out of garage, go about 3/4 down the driveway, and it sputters and dies again. Get it started again, make it around the block, but sputters and dies again in the driveway. Push back into garage. Disconnect MAF connector and blow into the electrical connections. Disconnect IAC connector and blow into the electrical connections. Undo negative terminal on battery and reconnect it. Starts up and runs fine. Take it around the block, then on a short drive around the neighborhood to friends house. Stop inside friend's house for a while. Come back outside, car turns on, but sputters and dies after about a minute. When trying to start it this next time, I listen for the fuel pump this time as I turn the key to accessory on. A few times turning the key with no fuel pump priming sound, but then on the ~4th try, I hear the pump prime, and it starts fine. I drive it straight home to the garage.
10/7- Check 30A fuse in BAP. Looks a little dirty, but not blown. Change it for a fresh fuse. Set key to accessory a number of times, it seems like it is priming the fuel pump every time. Start the car and let it run for a while, about 10 minutes or so. Turn it off and repeat. It stays running each time. Try taking it around the block. Sometimes it sputters under throttle, sometimes it does not. Pull back into garage. Order new fuel filter, and factory style Carter P76130S fuel pump assembly.
10/19- Take down fuel tank, install new fuel filter Motorcraft FG 986B. Old one was very dirty. Attempt to install new fuel pump assembly. The tiny plastic tab on sending unit breaks. Attempt to bond the plastic with JB Weld Plastic Bonder. Leave it to dry overnight. Attempt to install again, the tab breaks again. Try JB Weld Plastic Weld. Leave it to try for about an hour. This time, stick sender "arm" in first, then push the end of it into sending unit. Seems like it held and did not break off. Get everything back together. First time priming the fuel pump it sounded very different. Like a buildup of resistance. Starts up and runs fine for a while. Fuel gauge reads about 1/4, though there is about 1/2 in the tank. Give it a few light revs to about 2000 RPM, but instead of returning to idle of about 800 RPM, it hangs up at 1250-1500 RPM. IAC valve cleaned with 'parts cleaner' and MAF sensor cleaned with MAF cleaner. That was not enough. Throttle cable sprayed with a tiny amount of 'parts cleaner' near the throttle body. That solved the idle issue at the time. Go to fill up gas at nearby station. Tank reads at E even when full. So either the plastic tab broke again in install, the gas melted the Plastic Weld, or the sending unit itself was damaged in install. Whatever, I can deal with using my trip odometer as my means of knowing roughly how much fuel I have left, until it becomes annoying. Do some driving around the neighborhood, no issues.
10/27 - Started up on first try, however fuel pump did not have the same kind of buildup of resistance sound as it did on the first startup with the new pump assembly. Did some errands, started up and ran fine at each stop.
10/28 - Attempt to pull car out of garage to give space to change oil. Car turns over but will not catch. Changed fuel pump fuse under hood to a 30A, according to some recommendations on this forum when running a BAP. Put in new 20A fuses under dash for CCRM and Fuel Pump. Still no luck. Ordered new CCRM.
11/3- Installed new CCRM. Car started right up. Idle a bit high, about 1250 RPM. Turn car off. Oil change for Mobil1 Full Synthetic 5W30, Mobil1 M1-210A Oil Filter. Do a few trips around the block, then a short neighborhood drive. While making one turn in 1st gear, the car sputters. I pull over, and it sputters more and dies. I wait a minute. It starts on the second attempt. I do some more driving in the neighborhood, about 15 minutes worth, then head home. Order new Idle Air Control valve, thinking it may solve high idle RPM. Go back out later to run some errands, no issues.
11/4 - Go for first proper drive on highway. About 2 hours worth of driving, making stops about every 30 minutes to do errands. Starts and runs fine every time. Feels fine at half-3/4 throttle on highway. AFR about 15-16 at idle. On highway AFR shoots up to unreadable after getting off the throttle for a few seconds, then returns to about 14. About 12-13 on heavy but not full throttle. Come home. Let the car rest for about 5 hours, then do another 2 hours of straight highway driving with no problem.
11/7- Run some errands, starts, runs fine. Full throttle all is well.
11/9- 2 hours of straight highway driving, nonstop. Starts, runs fine. All is well.
11/10- I do not hear fuel pump prime. But the car starts and runs fine. 30 minute drive to the day's activity, runs fine, all is well. Car sits for about 3 hours. Go out for a spirited drive for about 15 minutes. I do not hear fuel pump prime. But the car starts and runs fine. Let it warm up for a few minutes. About 10 minutes into the drive, a minute after a 3/4 throttle pull, the car sputters in 3rd gear. I pull over, put it in neutral and it dies. Give it a minute. Start it up again, it's ok. Drive it about another 10 minutes then return to day's activity. Car sits about 3 more hours. Go to leave day's activity, I do not hear fuel pump prime. I let the car warm up for a few minutes in the ~35 F weather. I try to pull away and the car sputters and dies. Service Engine light on dash, with Fuel pump and FRPS codes on my tuner. Change the Idle Air Control Valve for the new one. Doesn't help. Try disconnecting and reconnecting the negative on the battery to reset the IAC valve, doesn't help. Try blowing into MAF, MAF connectors, and IAC connectors. Doesn't help. Try changing all fuses under dash and under hood that are related to fuel pump, CCRM or PCM. Doesn't help. Disconnect and reconnect negative to try to reset what the fuses affect. Doesn't help. Car towed home.
