Torque converter won't unlock?
05-10-2005, 09:54 AM
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Car: '87 IROC
Engine: 350 TPI
Transmission: 700-R4
Torque converter won't unlock?
Just finished a three-day thrash putting on a new water pump, double roller timing chain, oil pump, etc.
Cranked it up and it idles smooth & revs fine in neutral - but put it into gear and it's really rough - shaking the car, like the torque conv. is trying to lock up at idle in drive & reverse.
Tranny was rebuilt 5,000 miles ago and was working fine before the thrash.
It drives like a truck in that it feels like the Tq. conv. is locked up all the time. Shifting way too early w/no torque converter unlock/lock.
Adjusted the TV cable (as per manual's instructions) to no avail.
Other symptoms:
1) I notice is that there is no RPM reading from tach when cranking, and the tach is acting funny (bouncing occaisionally) when tached up around 3 grand...
2) A check of the tranny fluid level indicates that it is approx 1 to 1-1/2 pints too full (checked hot - idling in nuetral) It was dead on the money before!?!
What have I done to cause this?
Cranked it up and it idles smooth & revs fine in neutral - but put it into gear and it's really rough - shaking the car, like the torque conv. is trying to lock up at idle in drive & reverse.
Tranny was rebuilt 5,000 miles ago and was working fine before the thrash.
It drives like a truck in that it feels like the Tq. conv. is locked up all the time. Shifting way too early w/no torque converter unlock/lock.
Adjusted the TV cable (as per manual's instructions) to no avail.
Other symptoms:
1) I notice is that there is no RPM reading from tach when cranking, and the tach is acting funny (bouncing occaisionally) when tached up around 3 grand...
2) A check of the tranny fluid level indicates that it is approx 1 to 1-1/2 pints too full (checked hot - idling in nuetral) It was dead on the money before!?!
What have I done to cause this?
05-10-2005, 11:15 AM
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Car: 95 E-150 & 07 Kawasaki ZX-6R
Engine: A slow one & a fast one
Transmission: A bad one & a good one
Axle/Gears: A weak one & a chained one
Sounds like a bad TCC lockup solenoid. When youre cruising, try tapping the brakes....see if you can feel it unlock. If nothing happens then it's probably stuck. you can also connect a few jumper wires at the ALDL to force-lock the TCC, there's directions on the website somewhere...if you do that in 2nd gear and nothing happens then you got a problem..
Though from what I hear, the converters on third gens can only achieve lockup in 2nd, 3rd, and 4th... Other cars will lockup in 1st though, I dont know what's different with third gen converters...
Though from what I hear, the converters on third gens can only achieve lockup in 2nd, 3rd, and 4th... Other cars will lockup in 1st though, I dont know what's different with third gen converters...
05-10-2005, 04:32 PM
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Car: '87 IROC
Engine: 350 TPI
Transmission: 700-R4
I guess my main paranoia is that the wiring harness could theoretically have gotten pinched between the firewall and engine when I jacked it up to pull the oilpan (for the oil pump, double-roller timing chain, etc.)
Anybody out there know how to test a lockup solenoid, and/or the voltages that should be present at the plug? If I knew which wires to check for continuity back to the ECM (?), I could at least verify whether it's an electrical issue or the lockup solenoid itself...
Anybody out there know how to test a lockup solenoid, and/or the voltages that should be present at the plug? If I knew which wires to check for continuity back to the ECM (?), I could at least verify whether it's an electrical issue or the lockup solenoid itself...
05-11-2005, 07:21 AM
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Car: 1987 1SICIROC.....1999 TransAm
Engine: 385 HSR.....LS1
Transmission: 700R4 with Midwest 3400 2.4str...M6
Axle/Gears: SLP Zexel Posi unit 3.42's...3.73's
when pressing the brakes, what does is converter suppose to do? unlock? which makes the RPM's, go higher?
05-11-2005, 09:02 AM
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Car: 95 E-150 & 07 Kawasaki ZX-6R
Engine: A slow one & a fast one
Transmission: A bad one & a good one
Axle/Gears: A weak one & a chained one
Originally posted by Wishmaster's87IROC
when pressing the brakes, what does is converter suppose to do? unlock? which makes the RPM's, go higher?
when pressing the brakes, what does is converter suppose to do? unlock? which makes the RPM's, go higher?
05-11-2005, 06:38 PM
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Car: '87 IROC
Engine: 350 TPI
Transmission: 700-R4
Oh I am such an IDIOT... 
What the problem REALLY was...
Before jacking up the motor, I pulled the pass. side plug wires off the dist. cap to allow me enough slack to take the dist. cap off the dist. to avoid cramming it thru the firewall.
The engine was pretty warm by the time I'd rechecked timing, etc., so I got under the car (still up on jackstands) and had a buddy (who is still learning) confirm each wire I shook from below to ascertain each was connected to the right plug on the cap. "We" did not catch the fact that upon reassembly, I apparently got #4 & #8 wires switched. (That's it Paul - blame it on your buddy!)
As #4 & #8 are right next to each other in the firing order (1-8-4-3-6-5-7-2), I never got any backfiring out of the throttle body or exhaust to tip me off. In neutral, it didn't really idle too rough, and it would rev up w/o any of the commotion normally associated with switched plug wires.
(DON'T) Try this on your car to see what I'm talking about!
I shoulda rechecked all the plug wires myself after the motor cooled down.
My wire looms are now arranged so that 1-3-5-7 and 2-4-6-8 can be determined by their position in the looms. WITHOUT having to verify from below!
This is what happens when you ASSUME stuff...
As Homer Simpson would say - DOH!!!
Like I said - I'm an idiot... but glad to have this worked out. She runs great now.
Thanks to anybody that rubbed a couple of brain cells together to try to help me figure this out!
What the problem REALLY was...
Before jacking up the motor, I pulled the pass. side plug wires off the dist. cap to allow me enough slack to take the dist. cap off the dist. to avoid cramming it thru the firewall.
The engine was pretty warm by the time I'd rechecked timing, etc., so I got under the car (still up on jackstands) and had a buddy (who is still learning) confirm each wire I shook from below to ascertain each was connected to the right plug on the cap. "We" did not catch the fact that upon reassembly, I apparently got #4 & #8 wires switched. (That's it Paul - blame it on your buddy!)
As #4 & #8 are right next to each other in the firing order (1-8-4-3-6-5-7-2), I never got any backfiring out of the throttle body or exhaust to tip me off. In neutral, it didn't really idle too rough, and it would rev up w/o any of the commotion normally associated with switched plug wires.
(DON'T) Try this on your car to see what I'm talking about!
I shoulda rechecked all the plug wires myself after the motor cooled down.
My wire looms are now arranged so that 1-3-5-7 and 2-4-6-8 can be determined by their position in the looms. WITHOUT having to verify from below!
This is what happens when you ASSUME stuff...
As Homer Simpson would say - DOH!!!
Like I said - I'm an idiot... but glad to have this worked out. She runs great now.
Thanks to anybody that rubbed a couple of brain cells together to try to help me figure this out!
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