lockup clutch

My 1994 Trooper 3.2 with Gm automatic transmission has the lockup clutch. As I understand it, the clutch is controlled by pressure from the transmission creating a signal to the computer and then to the
clutch to engage or disengage. My Trooper seems to be unstable and seems to engage and disengage very often between 50 and 55 mph. Is there any way to make this feature more stable, like an adjustment or (perish the thought), a heavier or lighter fluid or additive? (I am not knowledgeable enough to even think of having the computer reprogrammed.) This is really annoying for it to be switching back and forth so easily in this speed range since the state speed limit here is 50 on secondary roads and I can't get it up to 60 and drive at that speed or I'd need an 'in vehicle file cabinet' to hold the speeding tickets.
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On Tue, 17 Feb 2004 21:44:03 GMT, snipped-for-privacy@yahoo.com (Oliver B. Lafferty) wrote:

actually you've got it backwards... the ecm commands the covertor solenoid to lock or unlock the convertor. does your trooper seem down on power? if so, you may want to look into replacing the fuel filter as you'll automatically push the accelerator down more to compensate for lack of fuel flow.
another place to look is your brake switch, as all autos will disengage the TCC on brake apply. I'd look towards the engine though.
-Bret
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wrote:

Thanks for the reply Bret, but the engine has lots of power and runs so smooth I sometimes think it's shut off at traffic lights. Fuel filter has been changed, but brake switch is something I'll check out. (replace) This does it in cruise control too so fuel flow is unlikely. I probably didn't make it clear that I thought (?) the ecm receives a signal from transmission pressure and then sends the command to the converter solenoid. Actually, I don't know what other inputs the ecm needs to control the solenoid, and my thought is that any of those inputs could cause the problem. I've had it to a transmission shop who took a ride and couldn't see a problem, but then they didn't seem too anxious to work on my Trooper at all. Oliver

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On Wed, 18 Feb 2004 13:30:43 GMT, snipped-for-privacy@yahoo.com (Oliver B. Lafferty) wrote:

if it's got the GM 4L30E trans.. (the one the Rodeo has). there's a bunch of different sensors in the trans, but the only ones that matter greatly (as far as lockup) are the speed sensor and a MAP (or whatever sensor is used in the trooper's 3.2 to denote engine load) sensor.
how is your fluid condition? nice and bright red or brown and stinky? cooked fluid can make all sorts of wierd things happen.
-Bret
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wrote:

The fluid is almost new. Had been changed although the original fluid didn't look bad. You're giving me some direction of what to do next. As soon as I get to work on it, (soon I hope) I'll change out the brake switch in case it's throwing a spike or glich at the ecm, and test and/or replace (probably replace) both the speed sensor and MAP. I'm locking in this exchange in my newsgroup reader so I don't lose it and definitely will get back to you to let you know how I make out. (don't go away, some personal things are keeping me from doing it immediately) Thanks, Oliver
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As long as I'm here in the Isuzu newsgroup, an update on the following old exchange. I have now replaced the speed sensor, the MAP sensor, the brake switch, located and repaired a vacuum leak in the intake manifold, temporarily replaced the ECM (with one from another Trooper), and added transmission fluid stuff by Lucas. It still does the in and out of the lockup clutch thing. Now this doesn't affect the driving, it just affects my head. The vehicle runs just fine with a smooth and strong engine, but my son's wife destroyed a perfectly good Oldsmobile because she drove it at a slow enough speed with an uphill load to keep the tcc disengaged or slipping to the point where the transmission heated up and the car caught on fire. I've since heard of other GM cars doing the same and since this transmission is a GM one, I am concerned that the transmission might be damaging itself if I keep driving it long enough. I can watch the RPM counter and hear the tone of the engine change as the lockup clutch goes in or out. Any thoughts from you guys?

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Oliver B. Lafferty wrote:

Have you replaced the throttle position sensor or the brake pedal switch?
Your transmission will run hot if it continues to lock and unlock. Not a good thing. I had a problem like this on a dodge. The only way to find the problem was to use a co-pilot. It is an expensive device dealers have that monitors the vehicles computer while you drive. It can note the status of various sensors when the TCC unlocks. In my case everytime the TCC unlocked, a split second prior the computer stated I had pressed the brake pedal. I had done no such thing. First thought was the pedal switch but it was good. Turned out to be a bad connection in one of the connectors.
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hello. i am highly intrested in your lockup clutch kindly tell me the last price and send me the pixs,my mode of payment will be a cashier check drawn from a uk bank cos i have an associate in the uk who sold some dameged cars on my behalf and has not paid all the money involved but i can instruct him to issue a cashier check so as to pay you.note i will only conclude this transaction when i conclude negotiation with my shipper on the price which he is going to ship the car from your location to where the customer that want the car to be shipped to.     if you are okay with my mode of payment and trancastion do get back to me with the following info............................ full name home address phone number zip code all this will be forward to my associate for payment. hope to hear from you soon. spencer snipped-for-privacy@graffiti.net
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hello. i am highly intrested in your Seals on injector
kindly tell me the last price and send me the pixs,my mode of payment will be a cashier check drawn from a uk bank cos i have an associate in the uk who sold some dameged cars on my behalf and has not paid all the money involved but i can instruct him to issue a cashier check so as to pay you.note i will only conclude this transaction when i conclude negotiation with my shipper on the price which he is going to ship the lockup clutch from your location to where the customer that want the car to be shipped to.     if you are okay with my mode of payment and trancastion do get back to me with the following info............................ full name home address phone number zip code all this will be forward to my associate for payment. hope to hear from you soon. spencer snipped-for-privacy@graffiti.net
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