Violent engine cut-out
Thread Starter
5th Gear
Joined: Dec 2007
Posts: 5
Likes: 0
Violent engine cut-out
Hi all, I posted this problem a few months ago and wasn;t able to find the problem. Perhaps there are some more ideas out there. here is what's going on with mu 1986 C4:
Engine starts great...runs fine, and can run up to 30 miles without a problem. Then, suddenly one of 2 things happens:
1) When I accellarate the engine lurches forward, dies out for a fractions of a second, and then kicks in at what seems like full throttle, then dies out, etc. It does this so fast that there is little time to react and the car ends up bucking like a bronco until I totally release the gas pedal. Something is cutting out and I cant find it.
2) On rare occasion, she will do this at traffic speed on the highway....very unpleasant experience. with no load however, I can rev the engine.
Could this be an ignition module problem?
Thanks for any advice
Engine starts great...runs fine, and can run up to 30 miles without a problem. Then, suddenly one of 2 things happens:
1) When I accellarate the engine lurches forward, dies out for a fractions of a second, and then kicks in at what seems like full throttle, then dies out, etc. It does this so fast that there is little time to react and the car ends up bucking like a bronco until I totally release the gas pedal. Something is cutting out and I cant find it.
2) On rare occasion, she will do this at traffic speed on the highway....very unpleasant experience. with no load however, I can rev the engine.
Could this be an ignition module problem?
Thanks for any advice
Melting Slicks
Joined: Jan 2001
Posts: 2,940
Likes: 5
From: Chesapeake VA
It could be the module.
Technically, I believe the L98 runs off of preprogrammed fuel maps at WOT, so the throttle position sensor(TPS) shouldn't cause the WOT issue, however, the bucking at highway speed could be a TPS issue. I mention this because I had a bucking issue with an 86' Crown vic and it turned out to be a bad TPS.
Technically, I believe the L98 runs off of preprogrammed fuel maps at WOT, so the throttle position sensor(TPS) shouldn't cause the WOT issue, however, the bucking at highway speed could be a TPS issue. I mention this because I had a bucking issue with an 86' Crown vic and it turned out to be a bad TPS.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
You need to put a fuel pressure guage onit and check the fuel pressure, then, take someone with you to watch the fuel pressure guage (tape it to the window) see if the fuel pressure drops as this conditions occurs. Could be the module....that's the next thing I'd check, take it to any Autozone, they'll check it for free. As far as the TPS goes you can check that and some other components with a Digital Voltage Ohm Meter. Hope you have a factory service manual for your specific year...impairative.
Advanced
Joined: Nov 2005
Posts: 95
Likes: 0
From: VA
What is you fuel level when it happens? It's a commn with early C4's problem with only a few gallons left and you stomp it. you'll burn up the injectors quick if you have this problem
only fix is a updated FP.
You might want to put a FPGuage on it too.
only fix is a updated FP.
You might want to put a FPGuage on it too.
