Starts but doesn't run
08-23-2006, 04:37 AM
#1
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Starts but doesn't run
A few weeks ago I posted regarding my '97 993TT which recently started running rough intermittently. See the previous thread here .
What began as a very infrequent problem has now become at least 90% consistent. Now, regardless of whether the car is hot or cold, it will start immediately, run poorly for a few seconds, and then die. I can keep it alive with throttle but misses very badly. If I turn it off and immediately restart 10-15 times in a row, eventually it will start and run normally.
It is not throwing any DTCs at the moment. When the problem first began I got a single P1501 ("fuel pump relay final stage short to ground"), but after clearing it, it hasn't come back. I went ahead and changed the fuel pump and filter, which made no difference. I've also changed the DME relay.
This is starting to feel like a DME problem to me. Any ideas or suggestions for troubleshooting? Anyone in the Los Angeles area have a DME they'll let me borrow for a couple of hours?
I'm about to give up and tow it to a dealer...help!
Thanks,
-Jeff
What began as a very infrequent problem has now become at least 90% consistent. Now, regardless of whether the car is hot or cold, it will start immediately, run poorly for a few seconds, and then die. I can keep it alive with throttle but misses very badly. If I turn it off and immediately restart 10-15 times in a row, eventually it will start and run normally.
It is not throwing any DTCs at the moment. When the problem first began I got a single P1501 ("fuel pump relay final stage short to ground"), but after clearing it, it hasn't come back. I went ahead and changed the fuel pump and filter, which made no difference. I've also changed the DME relay.
This is starting to feel like a DME problem to me. Any ideas or suggestions for troubleshooting? Anyone in the Los Angeles area have a DME they'll let me borrow for a couple of hours?
I'm about to give up and tow it to a dealer...help!
Thanks,
-Jeff
08-23-2006, 09:37 AM
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I had the poor running probs a while back. The car would run fine for ages, then just decide to start misfiring and die at random. After much work it turned out to be the alarm / immob system playing up, it was allowing voltage spikes and voltage lows. The lows causing the engine to eventually pack up as the V got lower and lower, and the spikes caused the plastic relay/fuse board around where the DMS's pins insert into, to melt. The voltage spikes also cooked abit of the ecu 
Hope you sort it.
Martyn.
Hope you sort it.
Martyn.
08-26-2006, 03:28 PM
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My ECU is bad!
Problem found: My ECU is dead. 
Fortunately, Kevin at Ultimate Motorwerks has been gracious about helping me with this, even providing me with a loaner ECU to verify the problem. Once again Kevin comes to the rescue...
-Jeff
Fortunately, Kevin at Ultimate Motorwerks has been gracious about helping me with this, even providing me with a loaner ECU to verify the problem. Once again Kevin comes to the rescue...
-Jeff
08-26-2006, 03:37 PM
#7
Three Wheelin'
I hope you sort your problems out. Kevin does many "gracious" things behind the scene. Three cheers for Kevin.....Hip, Hip, hurrray....Hip ,hip hurray.....etc.,
