2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

rough revving-why? please help!!

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Old Apr 25, 2002 | 09:40 PM
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From: Dover NH
rough revving-why? please help!!

I have an 87 T2 with a jspec motor. It revs rough and hesitates when I try to rev it up slowly in neutral. But revs fine when I go full throttle. The same goes for when driving-accelerates fine, but mid and low throttle is rough. BUT this only happens below around 3000 rpms (bad primaries?). I have tried injector cleaner too. My pedal is practically an on/off button when driving! I already readjusted the tps, and tried another one. I have a safc, intake exhaust etcetc. Could it be bad grounds? Its really annoying, and I have been living with it for about 6 months! My boost guage reads 15 lbs vaccuum at a 800rpm idle so I think a leak is out. it also idles crappy till fully warmed up(removed cold start), and misfires a bit while idling. Also how do I reset the ecu? Also safc is set at 5% low throttle, and 85% high throttle, is this wrong?

I tried the following-

-different tps, and readjusted
-searched for vac leaks(none)
-cleaned/replaced plugs
-injector cleaner


possibilites(maybe)-

-dirty/faulty primaries
-bad grounds from motor/ecu
-timing off
-still a vac leak


Any ideas? Ted, anybody?
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Old Apr 25, 2002 | 10:15 PM
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From: Dover NH
ttt
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Old Apr 25, 2002 | 10:54 PM
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From: n
Have you done the throttle body mod?


-Ted
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Old Apr 26, 2002 | 06:31 AM
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From: Dover NH
yup, but I had the prob just the same before I did that
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Old Apr 26, 2002 | 05:37 PM
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From: n
Spec the TPS's - they both could be bad.
Dump a can of brake fluid into the airflow meter - it could be dirty (AMF removed!)
Add more grounds - you could have a ground problem
Spark plug wires original?&nbsp Change them out


-Ted
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Old Apr 26, 2002 | 08:39 PM
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From: Dover NH
Ill try those things, thanx ted, but brake fluid? should I just blast the insides of it with brake cleaner or something?
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Old Apr 26, 2002 | 10:14 PM
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Oops, crap - typo!!!
"brake cleaner"!!!
Don't be dumping brake fluid on anything in your car except in the brake master or clutch master reservior!
My bad!



-Ted
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Old Apr 26, 2002 | 10:21 PM
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From: Half Moon Bay, CA
Originally posted by RETed
Oops, crap - typo!!!
"brake cleaner"!!!
Don't be dumping brake fluid on anything in your car except in the brake master or clutch master reservior!
My bad!



-Ted

little too late now pal!!! Thanks alot!! have you any idea what a mess the brake fluid made???? Jeesus christ!!!!!!!!
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Old Apr 26, 2002 | 11:20 PM
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From: Dover NH
Ted youll be happy to know that between those 2 posts of yours my faith in you didnt even waiver! And cymfc3s is right after I tried you brake fluid trick my car seems to run REALLY rough, trying mt 90 in the afm tomarow, thatll fix it up good!
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Old Apr 27, 2002 | 07:00 AM
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hmmm... that sounds unhealthy... but here's my tidbit
i experienced the same issue (before my rebuild). It seems as though my fc was running rich as a ****. (130km to a gas tank) After the rebuild, the revs are much smoother. I'm not saying that you need a rebuild... perhaps just adjust your air/fuel ratio. Worked for me
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