FM2 w/ Link - cuts out under boost, then remains in "limp" mode until rebooted
#1
FM2 w/ Link - cuts out under boost, then remains in "limp" mode until rebooted
Hitting a strange problem with my '99 (full details in signature link). Often, when accelerating under boost, the ECU will cut off: acceleration comes to a sudden stop, the sound system cuts out for ~1 second, and the computer seems to be put into a "limp home" mode. From then onward, I can't exceed 0 boost/vacuum or the fuel will cut out as if I'd hit the redline. Makes for interesting driving, constantly having to watch the boost gauge until I find a place to reboot the car.
Triggering this condition seems to be more a matter of "shocking" the system than raw boost. I can usually get all the way to peak boost (12psi) and keep it there as long as I don't mash the pedal en route. OTOH, it's easily triggered by making hard shifts that land @ WOT. I've even had it caused by a deep pothole in a parking lot at 5mph.
Anyone heard of something like this? Known fix?
Triggering this condition seems to be more a matter of "shocking" the system than raw boost. I can usually get all the way to peak boost (12psi) and keep it there as long as I don't mash the pedal en route. OTOH, it's easily triggered by making hard shifts that land @ WOT. I've even had it caused by a deep pothole in a parking lot at 5mph.
Anyone heard of something like this? Known fix?
#4
Well, the only reason I said that is because you mention the sound system cutting off for a split second and because jarring the car will cause your problem. I'd say check the connections at the battery first (the battery typically does not power the car after startup, but if you have a weak alternator, it could be). Basically, check your common grounds and power sources first and go from there.
If anyone else has an idea, I'm sure they will post up as well.
If anyone else has an idea, I'm sure they will post up as well.
#5
Agreed, I'd be looking for loose wires. I've seen a situation where a slightly-too-short ground wire would disconnect under big engine movements, cutting power to the ECU. The "limp-home" behavior is weird, there isn't one built into the ECU as far as I know. As RotorNut said, the sound system problem certainly indicates a problem outside the ECU, as the Link has nothing to do with that.
The best way to find wiring problems like this would be to do a wiggle test. With the engine idling, wiggle wires until you duplicate the problem.
The best way to find wiring problems like this would be to do a wiggle test. With the engine idling, wiggle wires until you duplicate the problem.
#9
Done some more testing. It now happens every time I reach WOT (whether suddenly or not) in 2nd, and almost always in 3rd. Never happens in 4th or 5th even if I stomp on it and zoom all the way to 100mph+.
I also had someone follow me yesterday night. After I accelerated to the "reboot" point, they said my car started putting out black smoke. I assume that's unburnt fuel, so yeah it's probably running super rich
I also had someone follow me yesterday night. After I accelerated to the "reboot" point, they said my car started putting out black smoke. I assume that's unburnt fuel, so yeah it's probably running super rich
#10
Done some more testing. It now happens every time I reach WOT (whether suddenly or not) in 2nd, and almost always in 3rd. Never happens in 4th or 5th even if I stomp on it and zoom all the way to 100mph+.
I also had someone follow me yesterday night. After I accelerated to the "reboot" point, they said my car started putting out black smoke. I assume that's unburnt fuel, so yeah it's probably running super rich
I also had someone follow me yesterday night. After I accelerated to the "reboot" point, they said my car started putting out black smoke. I assume that's unburnt fuel, so yeah it's probably running super rich