NEED HELP!!! part throttle miss/stumble after minor collision/curbing.

FlaBoy

Just a good ole boy...
Joined
Jun 6, 2003
On the way to work last night, while making a turn, a guy on a bike rode out in front of me. After slamming on the brakes to keep from killing him, i spun a little on the wet road, and ended up curbing the car pretty hard in the rear. I didnt hit the guy, but my rear pass. side wheel swept into the curb at pretty much a right angle. There was no serious damage to the car, but the impact was hard enough that my engine died (?!?!) and on closer inspection i saw that a peice of the outermost rim of my tire had snapped off (the tire seems to still hold air fine). When i restarted the car, I immediately noticed a problem. At idle, it was running rough, sounded like it was mis-firing a little. When i REALLY notice it is on light throttle acceleration. If i am crusiing at a steady speed, it just seems like its running a tiny bit rough. But when i accelerate at anything up to about 1/3 or 1/2 throttle, it stumbles, and bucks and misses like CRAZY. the more throttle i give it, the smoother it runs. Once i get about 1/2 throttle, it smooths right out, and runs fine. When i give it a full throttle blast, it pulls just as strong as before, and seems to have no issues, but the second i get into vacuum instead of boost, it starts stumlbing, missing and bucking again. I have also noticed that as I'm driving, when its in vaccum on the boost gauge is when it runs badly, but as i get closer to zero vaccum and zero boost it starts to smooth out, and once I'm in boost it seems to be running just like normal. I am friggin CLUELESS as to what could be wrong. since i don't want to drive my car anymore than I have to until i figure it out, for fear of doing more damage, and its my daily driver, I obviously need to figure this out quick. Besides the rough running, nothing else seems wrong... the coolant temps, and oil pressure and everything seem fine. I just got a scanmaster, so i dont really know how to interpret its readings yet, but I can post them here if that will help. If anyone has any thoughts or suggestions, i would be very appreciative. Thanks!!!
 
Just a shot in the dark... I would look at the vacuum lines on top of the throttle body and the intake. It would seem like if the car is in vacuum during idle, you could have a vacuum leak some where. I would take some starter fluid and spray around vacuum lines. Make sure all the vacuum lines are tight and not cracked. This would be the first thing I would do. If it smoothed out at 1/4 to 1/2 to full, this would tell me that either a intake (vacuum ) or possible exhaust leak. Hope this helps...

Chuck
 
It still pulls the same healthy ajmount of vaccuum it did before I curbed it (17-18 in. in idle when warmed up) and a visual inspection of all the vaccuum lines showed they were all still attached and routed properly. I replaced every inch of vacuum lines and every connector less than 3 months ago (previous owner had them routed wrong, and lines were falling apart) so I dont think the impact would have cracked/broken any of them. I will probably do the old propane/starter fluid test around the vaccuum block etc. tomorrow just to be sure. I'm still kind of new to these cars, so forgive my stupidity, but how/why would an exhaust leak cause this stumbling/misfire? I know the pass. side exhaust tip got banged pretty good when the car curbed, so its very possible my whole exhaust system got a pretty good impact, its def possible it knocked something loose. Any easy way to check for exhaust leaks? I mean obviously, you can feel the gas blowing out, but theres a few places on my car i woudlnt want to stick my hand while the things running for fear of burning it off :) any easier way to check for leaks? thanks for the help, and please, I welcome any and all ideas or suggestions.
 
check the hotwire kit you got underneath and make sure all your wires to the FP and all are still intact, and not pulled apart/separated....To me it sounds like a fuel delivery prob...Maybe some soot got knocked around in the tank and is now hung up in the sock or the pump wire on top of the tank got banged loose...just my opinion.....

Good luck!!!

John
 
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