Car running rough, what could it be?
06-07-2003, 10:36 AM
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Car running rough, what could it be? Last week I installed a polyurethane trans mount, polyurethane motor mounts, and NGK plugs (gapped at 0.060"). While I was under the car I decided to adjust my y-pipe and splice all ten wires in the wiring harness that leads to the starter and passanger side O2s. I sliced the wires in order to reroute them away from the header.
During the process of adjusting the y-pipe I removed all of the O2 sensors. When I reinstalled the sensors I put anti-seize on the threads. Unfortunately I got confused with which one of the passanger side O2s was the front and which one was the back. I'm 99% sure I figured it out I placed them in the right location.
After I finished all the work I reset the pcm.
Now for the problem. At idle the car runs fine. However if I hold it at 1300 RPMs the car runs very rough (kind of stumbling). If I bring it up to 1400 RPMs the car starts running fine. However, once the car gets into the higher RPM range (say above 3000) it starts running rough again. Just the other day the SES light came on but I did not have a chance to check it. Hopefully I can check it today.
Does anyone have an idea of what it could be or where I should start looking? I'm really confused and concerned.
Thanks in advance and sorry I was long winded!!
Jim
During the process of adjusting the y-pipe I removed all of the O2 sensors. When I reinstalled the sensors I put anti-seize on the threads. Unfortunately I got confused with which one of the passanger side O2s was the front and which one was the back. I'm 99% sure I figured it out I placed them in the right location.
After I finished all the work I reset the pcm.
Now for the problem. At idle the car runs fine. However if I hold it at 1300 RPMs the car runs very rough (kind of stumbling). If I bring it up to 1400 RPMs the car starts running fine. However, once the car gets into the higher RPM range (say above 3000) it starts running rough again. Just the other day the SES light came on but I did not have a chance to check it. Hopefully I can check it today.
Does anyone have an idea of what it could be or where I should start looking? I'm really confused and concerned.
Thanks in advance and sorry I was long winded!!
Jim
06-07-2003, 10:43 AM
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Re: Car running rough, what could it be? Really Jim, you have to find out what the DTC is. When you find out, post it here, and I'm sure someone can help.
Good luck!
Good luck!
06-08-2003, 12:07 PM
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Re: Car running rough, what could it be? Predator, thanks for the quick reply!
First of all, I need to admit that I'm a dumba$$! After checking the error codes it was obvious that I did in fact install the O2 sensors in the wrong locations. Once I switched them back to their proper locations the SES light went away.
Then I reset the pcm and the car still seemed to be running a little rough, even though it ran strong at WOT. Here's another embarassing part! I'm not positive, but I'm starting to convince myself that the car is fine. The only reason why I thought something was wrong was because I felt a lot of vibration in the steering wheel and then the SES light came on. This all occured immediately after the motor mount install . Now I'm thinking its normal for polyurethane motor mounts to transfer that much vibration to the steering wheel. So it's prabably just my inexperience with modifying cars that caused me to jump to the conclusion that something was wrong. Anyway, this is an assume site and thanks for putting up with some of the stupid questions that come from the less experienced people like myself.
Thanks,
Jim
First of all, I need to admit that I'm a dumba$$! After checking the error codes it was obvious that I did in fact install the O2 sensors in the wrong locations. Once I switched them back to their proper locations the SES light went away.
Then I reset the pcm and the car still seemed to be running a little rough, even though it ran strong at WOT. Here's another embarassing part! I'm not positive, but I'm starting to convince myself that the car is fine. The only reason why I thought something was wrong was because I felt a lot of vibration in the steering wheel and then the SES light came on. This all occured immediately after the motor mount install . Now I'm thinking its normal for polyurethane motor mounts to transfer that much vibration to the steering wheel. So it's prabably just my inexperience with modifying cars that caused me to jump to the conclusion that something was wrong. Anyway, this is an assume site and thanks for putting up with some of the stupid questions that come from the less experienced people like myself.
Thanks,
Jim
06-08-2003, 03:28 PM
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Re: Car running rough, what could it be? Hey Jim, the only stupid question is the one you didn't ask 
.
I've never had polyurethane motor mounts, but it seems reasonable that the car would indeed feel different, it would almost have too. There's quite a difference between rubber and pu.
I relate completely to what you're saying: I always feel paranoid and convinced that something is wrong with my car after doing a modification, and we're probably not alone on that one either.
Anyway, it just seems that you need to adjust or get used to the new way your car feels. Enjoy your car!
.I've never had polyurethane motor mounts, but it seems reasonable that the car would indeed feel different, it would almost have too. There's quite a difference between rubber and pu.
I relate completely to what you're saying: I always feel paranoid and convinced that something is wrong with my car after doing a modification, and we're probably not alone on that one either.
Anyway, it just seems that you need to adjust or get used to the new way your car feels. Enjoy your car!
06-14-2003, 09:27 AM
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Re: Car running rough, what could it be? O.K. I was wrong there is something wrong with my car!!! Last year I ran 13.48 @ 106.41 mph with a 2.21 60'. Yesterday I ran 13.7 @ 104.2 mph with a 2.28 60'. Between the two runs I tuned the car with a MAFT to 13.2 a/f (that equated to 0.93 on the 02 sensor, previously it read 0.98). In addition, I descreened my MAF, removed both baffles in my hood, installed NGK TR55s, Pro 5.0 shifter, and ployurethane trans and motor mounts. Now my e.t. is 2/10 slower and I trapped 2.2 mph less. 
My SES light is not on, but the car is running rough. Prior to going to the track I though that I was just feeling additional vibration due to the polyurethane. Now I think I must have hurt the engine some how between the two track outings and the polyurethane made the problem more obvious. Unfortunately, I did have a 3 to 2 shift at about 100 mph (before the Pro 5.0). I thought I caught it in time and pushed the clutch back in. Could I have possibly broken a spring and not realized it until I put the motor mounts in? Is there any was to check with Atap? Or does anyone have an idea of what might be wrong?
Thanks
,
Jim
My SES light is not on, but the car is running rough. Prior to going to the track I though that I was just feeling additional vibration due to the polyurethane. Now I think I must have hurt the engine some how between the two track outings and the polyurethane made the problem more obvious. Unfortunately, I did have a 3 to 2 shift at about 100 mph (before the Pro 5.0). I thought I caught it in time and pushed the clutch back in. Could I have possibly broken a spring and not realized it until I put the motor mounts in? Is there any was to check with Atap? Or does anyone have an idea of what might be wrong?
Thanks
,Jim