my 1993 rs 3.1 automatic occasionally stalls when i bring it to a stop. my mechanic hasn't been able to resolve this. hes serviced transmission , replaced idle control valve, and map sensor. frequency has diminished but persist. anyone experienced this? any suggestions? thanks.
When the plugs and wires been changed? Fuel filter?
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
If your transmission fluid was toast or just say in it a longgg time,it could have burned up the TCC solenoid.These are on the automatics and in short old fluid loses it protective value and can over heat this switch and make the car cut off in gear like D or R or coming to a stop!Even though you have new fluid that is good but,I suspect this switch could be faulty and a simple check is to unhook it and see over a day or two or however long this takes to repeat itself.IF it goes away replace the switch.Unless your egr valve is sticking this would also factor in for idle,and or general running.These both may or may not be the problem but,I would at least humor yourself and check them both.
EGR valve is actually a pretty good call.
- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
Check your brake booster ad pcv valve hoses also...............Also the connections to the ignition module and the computer ground wires are clean. ( they are on one stud on the motor somewhere)
But more likely its the TCC solenoid as mentioned above.
Doug in P.R.
92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 155K miles. Hurricane Maria Survivor ! ( It takes a licking and keeps on ticking ! ).....in Salinas, Puerto Rico!
Good call on the TCC solenoid. Had my mechanic disconnect it and the stalling problem has disappeared. Now how important is it to replace? I've been driving it for about a week and everything seem fine, do I need one? What's it for anyways?
The tcc is designed to help control power and mpg for the trans to engine.If you want a more technical reading do a search with say tcc solenoid purpose to read up.I suggest replacing this part.Now the reason the old part failed was due to the atf has lost it's additive protection in the fluid and as time goes by the fluid gets hotter and provides less wear protection.In turn it gets the tcc to HOT and fries it.So in short have your atf replaced along with a new filter and THEN replace the part as just replacing the part and NOT doing a trans service will only burn up the new part and not add any life to your aging trans as it stands.I would like say half the hourly rate your would be mechanic gets paid since I established the root of the problem and he simply unhooked said issue.Just kidding but it humors the crap out of me how the so called know it alls did not know to even check this or maybe the issue popped up after the fact and you asked here for some ideas etc.Glad this seems to be the culprit and get the part,fluid,filter done all at once to make it like it should be not just unhooked(this part serves a purpose) for a good reason.
mark avery wrote:Good call on the TCC solenoid. Had my mechanic disconnect it and the stalling problem has disappeared. Now how important is it to replace? I've been driving it for about a week and everything seem fine, do I need one? What's it for anyways?
You will just lose a little gas mileage , thats all .Leaving it disconnected will not harm anything.
Doug in P.R.
92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 155K miles. Hurricane Maria Survivor ! ( It takes a licking and keeps on ticking ! ).....in Salinas, Puerto Rico!
I realize this is a little late, but it is VERY important. I had the same issue and did the same thing.
I was talking to the guys at a local TranStar store here in Po'Dunk Idaho about how I just fixed the problem by unhooking it.
They told me that it would cause damage if left unhooked for too long. The reason is that in high gear (third for us) the torque converter (TC) output shaft (turbine) is not turning at sufficient speed to properly lubricate the system. (I NOW understand what they meant AFTER taking the trans apart for an overhaul. The output shaft of the TC is the oil pump drive shaft for the whole transmission. It MUST spin fast enough to keep line pressures adequate and provide lubrication and cooling.)
They DID say that as long as I didn't take any trips with it (long periods in third) I SHOULD be fine around town. Also, that since we DO only have third, and not OD, that it wouldn't fry it as fast as it would for a four-speed (such as the 4T40, etc.)
But that was enough to get me to change it ASAP. It can be done in-car through the driver's side wheel well. It was a $20-$30 part and took me like two hours to complete. Don't forget the gasket (or RTV) for that side pan!
Just thought I would pass it along. I trust these guys- ESPECIALLY with GM transmissions.
Thanks for your time! Good Luck!
I driven 2 cars with it disconnected for years and the trans on both never failed? ( one was a Citation in AZ, the other was my current Sunbird here in P.R. with no reverse till I switched the trans)
Never heard that before............................................
Doug in P.R.
92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 155K miles. Hurricane Maria Survivor ! ( It takes a licking and keeps on ticking ! ).....in Salinas, Puerto Rico!
Just think about it for a minute, if you never got over 35-40 MPH ( city driving /stop and go) the life of the car and the lock up never came on, would the trans fail? ( city driving is worse on a car than highway driving.............. more heat generated)
The weakest part of the TH125/125C trans is the 2nd gear band.
The answer is no , the trans would not fail, its made to run in 3rd 90% of the time without lockup.
Doug in P.R.
92 Pontiac Sunbird LE, 2.0, AT, Red / Black with Grey 155K miles. Hurricane Maria Survivor ! ( It takes a licking and keeps on ticking ! ).....in Salinas, Puerto Rico!
Right?
...I guess I should think about it for a minute. I'm sure that the engineers and designers at GM probably just had a big bin of these solenoids lying around and thought: Hmmm... how are we going to get rid of all these solenoids? Well, I guess we could just put them in whatever TH 125Cs that come around. That way when they fail, people can just unplug them and be on their way. No need to design them into the integral function of the oil system...
All I know is that is what they told me at the Transmission Parts Retailer. I think that by what they were telling me, it's the 10% they were worried about, not the 90%.
Just a bunch of parts pushers, right? All they wanted to do was sell me a $20.00 part and a $2.00 gasket.
But that was in lieu of selling me a $200.00 rebuild kit. They even said that it might never affect the 125C, especially around town. But in a 4T-40 and bigger, the low RPMs of the engine can cause oil starvation because the oil pump is driven by the turbine in the TC. At highway speeds and low engine RPMs, (highway driving) the trans is turning quickly and the pump is not. (The pump is driven solely by the TC) Torque converter basic operation principle is explained in most repair manuals. The turbine is required to turn at a lower speed than the impeller, or else you could never stop while in gear. Without a TCC (the thing that solenoid operates), the pump is not turning quite fast enough to provide adequate flow for cooling at sustained highway driving. This reduced flow (especially in "well seasoned" transmissions) can also lead to a decrease in line pressure holding the high gear clutches and result in excess heat.
But that's just what they told me to sell me a solenoid and a gasket. Those crooks! I want my $30.00 back!!! Just kidding. Those guys are great.
I'm no mechanic, by any means. All I know is what they told me. IMHO, If it's something you feel confident on being able to do, why not do it? It can be done in-car, like $30.00 in parts, and is better to be safe than sorry. It pays for itself in gas in about 3 months, and then you are worry-free about line pressures dropping if you DO want to take it on a long trip.
IDK- I guess I should just think about it some more.
Just my 2 cents worth.
I have been running my 2 1st gen J's for years without the TTC hooked up for years and no problems to present.
Something I don't quite understand is the issue of the output turbine shaft driving the pump. When TCC is engaged wouldn't the output turbine shaft be bypassed by the locked up shaft to the input converter? Somewhere the power of the engine is being used directly off the crankshaft in lockup mode, and the Converter is not being used.
Perhaps someone can straighten me out some......LoL
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