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Discussion Starter #1
Hello all, I've owned an 89 Corolla GTS for nearly 3 years. In certain situations I experienced what I deemed to be "normal" jerking of the car when decelerating in 1st or 2nd gear.

In recent months, however, this jerking has significantly increased to the point that if I don't ride the clutch heavily for take offs and shifts into second, it jerks violently front to back until I mash the throttle and get around 3500rpm in 1st or 2nd. This problem is more noticeable with slower take offs (driving through parking lots, etc.) and almost non-existent when "launching" the car with greater acceleration. Did I mention that I have a pretty significant exhaust leak as well (Back pressure issues?)

I've changed the spark plugs and WD40'd the throttle cable at the motor and the pedal. Other threads mentioned something about the TPS and the device that slows the deceleration of the throttle(name escapes me).

The throttle deceleration device seems to work ok, I do not know what a TPS is to locate it under the hood.

Sorry if this question has been addressed in the past, but does anyone have any advice. I'd love to keep this car as we have a couple of kiddos at home and the budget is tight. Not to mention that I love this car!

Thanks
 

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Corolla & Avensis
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TPS=Throttle Position Sensor

It's on the back of the throttle housing. The round black thing with a connector attached to it

A picture of my website that might help:



Be carefull though...it's quite delicate.

How is you're clutch?? I think you should look for the problem there...
 

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Discussion Starter #3
Thanks for the pic, I'll take a look and definitely be careful. My mechanic told me last year that it felt like it was towards its end, although it was functional. That was a year ago however, I suspected it might be the clutch, but I'd never had one go out, so I don't know what it feels like. The shaking begins once I've let my foot off the clutch entirely.
 

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Rawr!
1988 Corolla Sedan
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82 Posts
Thanks for the pic, I'll take a look and definitely be careful. My mechanic told me last year that it felt like it was towards its end, although it was functional. That was a year ago however, I suspected it might be the clutch, but I'd never had one go out, so I don't know what it feels like. The shaking begins once I've let my foot off the clutch entirely.
I have the same issue with my carbureted 4-AF sedan, so it's NOT the TPS causing it.

Others have told me it has to do with worn out engine mounts. If you tap the throttle rhythmically, does the car shake out of its own momentum? If so, it's probably the engine mounts. Kinda scary but true.

4-AF clutches are extremely long lasting because of the lack of power output. There was a thread where members were all laughing about their serious clutch abuse and the thing still holds out after 200k of mileage and years of clutch dumping in 2nd and stuff, so I don't think it's the clutch.

Clutches wearing out (from what I know) primarily 'slip'. Say when you release the clutch when it should normally work, instead it will not grab and engage driving...you will hear the revs go up as if the clutch is not engaged even if the pedal is fully let off kinda thing. I'm sure there are other things that can go wrong related to the clutch (ie: flywheel gears shearing from abuse), but the clutch itself is simply a grip pad and as far as I know the only thing it can do wrong is stick in place (not very likely - would more likely be caused by the clutch controls having issues) or more commonly slip when trying to grab.

That being said, I have not properly diagnosed or solved our problem. I am quite certain though that it is the mounts...others told me it could be the carb, but if you're having it on EFI than it's probably not true.

Unless you do the mount replacement yourself (if that is indeed the case) it's not worth it for a car of this value to get it done by the shop I don't think :(

Post back with your findings. Maybe the clutch is doing it, but I'm doubtful.
 

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Put your car in 4th or 5th gear...which ever is highest. See if you can let the clutch out and take off from that gear. If you can, then the clutch is worn out. If the clutch is good the car should stall out in that high of gear.
 

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1988 Corolla SR-5
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Consider vacuum leak and gummed up throttle plate also.
 

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Homer Lusk Collyer
AE92
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I have the same issue with my carbureted 4-AF sedan, so it's NOT the TPS causing it.
At least some carbed 4AFs have TPS. I know mine does, can't speak for 'em all though. Does it shake on the highway at partial throttle sometimes?

As mentioned though, it's probably the motor mounts. Do you get a Check Engine Light?
 

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Corolla & Avensis
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I had my 3S-GE Carina shutter as the clutch just slipped, grabbed on...slipped, grabbed on again etc. when I was going up a steep hill in 5th gear on the freeway. It felt like I was on a very bad road.
Replaced the clutch and everything was well again. :-D

In my Corolla (with nearly 400.000km on the original clutch!) the clutch was getting worn and I had some jerking back and forth aswell sometimes. Not to bad yet, but I was getting worse.

For that clutch test kcwa mentioned before, the car should stall in 3rd gear aswell. If you can drive away in 3rd...then it might be worth while to look at the clutch.

As for the enginemounts...I never really heard of that problem...even with older cars. I'm not saying that couldn't be it. But it wouldn't be the first thing I'd think of
 

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99 TRD Camry
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I had a similar problem. It turned out to be torn intake pipe (rubber hose between throttle and AFM). Take it off and inspect it.
 

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Discussion Starter #11
Thank you for all of your quick responses. No check engine light, I am going to look into swapping out the motor mounts as that seems to be the most likely of the problems (I think). I found a few aftermarket upgrade mounts for an 89 GTS that were pretty expensive. Any ideas on where to find these parts? I'm assuming "normal" parts shops won't have them in stock given my last few parts hunts for this car.

Thanks again!
 

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1988 Corolla SR-5
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Thank you for all of your quick responses. No check engine light, I am going to look into swapping out the motor mounts as that seems to be the most likely of the problems (I think). I found a few aftermarket upgrade mounts for an 89 GTS that were pretty expensive. Any ideas on where to find these parts? I'm assuming "normal" parts shops won't have them in stock given my last few parts hunts for this car.

Thanks again!
Advance Auto Parts, Autozone, or NAPA will either have in stock, or can order them for you.
 

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i dont want to sound stupid but, did you check your air intake hose for rips like TRDKAMURI99 originally suggested?
 
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