RanciD
08-19-2009, 11:36 AM
I've been searching around trying to figure out what's wrong and haven't been able to dig up anything quite like the problem I'm having. This just started today after about 15 minutes of driving on a really, really torn up highway with 450/400 lb springs (a bumpy ride to say that least).
To put it simply the car only likes to accelerate. As soon as I stop accelerating, including just letting off the gas enough to stop accelerating and hold a constant speed, I lose power to the wheels. I would accelerate gradually up to around 65 mph then as soon as I let off a little to coast at that speed the car would buck forward and decelerate as if I had lifted completely off the throttle. It would drop to around 50 mph pretty quickly then the power would come back and bring me back up to 65 nice and smooth until the same thing happened. These speeds are just an example, this happens in every gear at any speed I try to coast at.
While all of this is happening the engine RPM doesn't really move much, and if I stab the gas after it begins decelerating it will hesitate for a second like it's waiting for something to catch then begin accelerating normally, similar to the clutch slipping then suddenly catching. When it catches the engine rpm will suddenly drop a bit to match whatever speed the car has decelerated to. I'm pretty confident it's not the clutch because the car is absolutely fine while accelerating, even under high load in fourth or fifth gear, but it's a similar sensation in that it feels like something is slipping then suddenly catches.
The engine itself idles fine and accelerates fine without any bogging or hesitation. If I rev the car in neutral it revs nice and freely, no stumbling or anything and drops back to idle normally. The engine and drivetrain are all completely stock, KA24DE, etc. Car has an untouched stock open differential. Could this be a differential or transmission problem? If I left anything out let me know but that pretty much sums up my problem. Thanks for any help in advance.
To put it simply the car only likes to accelerate. As soon as I stop accelerating, including just letting off the gas enough to stop accelerating and hold a constant speed, I lose power to the wheels. I would accelerate gradually up to around 65 mph then as soon as I let off a little to coast at that speed the car would buck forward and decelerate as if I had lifted completely off the throttle. It would drop to around 50 mph pretty quickly then the power would come back and bring me back up to 65 nice and smooth until the same thing happened. These speeds are just an example, this happens in every gear at any speed I try to coast at.
While all of this is happening the engine RPM doesn't really move much, and if I stab the gas after it begins decelerating it will hesitate for a second like it's waiting for something to catch then begin accelerating normally, similar to the clutch slipping then suddenly catching. When it catches the engine rpm will suddenly drop a bit to match whatever speed the car has decelerated to. I'm pretty confident it's not the clutch because the car is absolutely fine while accelerating, even under high load in fourth or fifth gear, but it's a similar sensation in that it feels like something is slipping then suddenly catches.
The engine itself idles fine and accelerates fine without any bogging or hesitation. If I rev the car in neutral it revs nice and freely, no stumbling or anything and drops back to idle normally. The engine and drivetrain are all completely stock, KA24DE, etc. Car has an untouched stock open differential. Could this be a differential or transmission problem? If I left anything out let me know but that pretty much sums up my problem. Thanks for any help in advance.