Auto tranny problem

[Ameer Antar]

It sounds like you have 2 problems here:

1. car wants to go when you brake
2. engine hesitates when you accelerate

As for #1, my Chevy Lumina also does something similar, especially after taking it up to 85 or so and then slowing down at an exit traffic light. I'm not 100% sure, but a friend w/ the same car said it was the tranny. Basically, the tranny wasn't down-shifting, so even though the car was only going 10-15 mph, it was stuck in 2nd gear. Since the engine has a minimum idle speed, the idle speed controller fights w/ the brakes, b/c idle speed in 2nd gear is more than 10-15mph. Mine has a similar feel, and it also feels like it will stall (and does sometimes). I also had this problem on a Pontiac 6000 which had a torque converter lockup system. The system eventually had problems disengaging and would stall the engine all the time. The solution on that was to just unplug the lockup system. Unfortunately on more modern trannies, I think the solution is either a rebuild or replacement (probly the cheaper method).

For #2, this seems like the engine is becoming lean when accelerating. If the engine gets a lean mixture it will hesitate and feel like you lost power for a second. The ECU can probably compensate, but there is a limit and may take a while to respond. I highly suspect a vacuum leak somewhere in the intake system. Leaks are common on these cars and cause lots of trouble. You should remove and check every hose (esp. the big ones) b/c the problem probly won't stare at you in the face. Cracks are often on the underside or near the clamps. Also there are things like oil cap and valve cover leaks that can cause trouble too. This place is a good place to start running down the checklist:

http://www.sjmautotechnik.com/vac.html
http://www.sjmautotechnik.com/trouble.html

Hope this can help solve at least one of the problems cheaply.. good luck.

-Ameer

---Original Message---
Date: Fri, 13 Feb 2004 11:07:21 -0500
From: Doug Yoder <yoderw at msoe.edu>
Subject: Auto tranny problem
To: quattro at audifans.com
Message-ID: <402CF639.30801 at msoe.edu>
Content-Type: text/plain; charset=us-ascii; format=flowed

Hi everyone-

My '91 100 (non-q) has some driveability issues which I think are 
related to the transmission, but I'd like to get some other opinions too. :)
Car drives OK most of the time, but when I am accelerating in low RPM 
(under 2500 or so), the car shakes a lot.  The happens usually in higher 
gears.  When braking and while stopped at a light, the car "wants to 
keep going" (thats the best way to say it, I think).  IE, when braking 
it feels almost like you're driving with one foot on each pedal.  Also, 
the car hesitates a little when you press on the accelerator (worse when 
you stomp the pedal, still there a little when you are gentle).
To me, this sounds like the torque converter is slipping.  Any other 
ideas?  I have no experience with working on transmissions... is the 
torque converter something that can be fixed/replaced easily?  Will I 
need a new/used tranny?  If the torque converter is replaced is it worth 
doing the tranny at the same time (ie, you're in there anyway...)?

Thanks,
-Doug

By the way, this is a 097 4-speed slushbox under dicussion.

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|    Doug Yoder    |   wdy at zordok.net   |    http://www.zordok.net/    |
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