Help!! Installed (2) new switches, filter/fluid, Still a Problem

[nuc]

Help!! Installed (2) new switches, filter/fluid, Still got a Problem

Bought 2 new switches, filter and gasket form PTS, still no luck tho.

Problem is that when the tranny shifts into 3rd, it feels like it "bobbles" (for lack of a better word) back and forth between 2nd and 3rd. This is only at part (normal) throttle around town. It feels to me like the TCC is engaging and disengaging back and forth, unless I speed up or slow down.
If I slightly press on the brake(which I think disengages the TCC) the problem does not happen. B/C I already R&R'd the 2 switches does that tell you that the problem is the TCC switch? Or something else?


Thanks

Adam

 

[Russ Merritt]

What about the solenoid? Did you change that too?

 

[nuc]

I changed the 2 pressure switches only. Doesn't the TCC solenoid have to receive a signal to activate? Is there something that could be signaling it to activate when shifting into 3rd gear at low acceleration?

 

[Russ Merritt]

Yea, it comes from the chip at a preprogramed mph. If it's coming on at slow speed, it's somehow being manually being turned on. See if it happens with the plug unplugged on the side of the trans. If it does, it's not an electrical problem. It's mechanical.

 

[nuc]

If it was a mechanical prob. with the TCC why would pressing the brake pedal slightly keep it from happening? There is an electrical switch at the pedal and if the problem was mechanical the brake switch wouldn't help, right?

 

[Russ Merritt]

True. Stock chip?

 

[nuc]

max effort 8 position

 

[RareT]

Originally posted by nuc
If it was a mechanical prob. with the TCC why would pressing the brake pedal slightly keep it from happening? There is an electrical switch at the pedal and if the problem was mechanical the brake switch wouldn't help, right?

Sounds like your TCC switch is bad. The reason it seems to be fine when you tap the brakes is the TCC will not engage when the brake is depressed.

 

[chris718]

everytime the solenoid is engaged a magnetic field is generated .this causes fine particles of metal in the oil to collect in the solenoid body sometimes generating sticking.the solenoid sounds like it is not doing its job ,or the ecm command for lockup is being given at the wrong time based on false data collected from the sensors /switches on the vehicle or the ecm.

 

[nuc]

So, next step is to drop the pan again and replace the solenoid?

Or is there a way to verify that it is a solenoid problem and not a computer problem. I'd hate to drop the pan, replace the solenoid and still have no luck.

I do have turbolink.

Thanks for the replies so far.

 

[Russ Merritt]

Doesn't T-link tell you when the lock-up is being commanded?? Direct scan shows when the convertor is being told when to lock.

 

[nuc]

Ok, ran the car with t-link and it showed that when shifting into 3rd gear the TCC was locking and unlocking. Does this narrow anything down?

What should I do next?

Thanks

 

[Russ Merritt]

So it is being commanded and then turned off and so forth.

 

[chris718]

you must answer russs question.

 

[Russ Merritt]

If it's being commanded, check the wiring harness going to the trans for a grounded wire.

 

[nuc]

Sorry for the length, just trying to figure this out.

The t-link shows that the TCC is coming on and off in 3rd gear at light throttle ~30mph. If the problem was a ground, wouldn't this occur in fourth gear also?

Just trying to reason this through:

If a wire was grounded in the harness, then holding the brake pedal slightly down, thereby opening the switch on the brake pedal should have no effect on the TCC locking and unlocking. However, when I do this the TCC unlocks and does not relock.

Also, if the problem was a ground then the TCC should lock and unlock when I am in fourth gear and going highway speeds, however, it functions normally. Disengaging when I press the brake and reengaging when I let off the brake.

I am feeling stumped. It seems to be leading to a computer/chip problem b/c if it was a bad solenoid the locking and unlocking should be happening in fourth also, right?

 

[Russ Merritt]

That's what you'd think. Have you tried another chip?

 

[nuc]

I've got 55lb. injectors and a ME 8 pos. for them. Anybody out there interested in loaning me a chip for 55's?

 

[nuc]

Ok, maybe someone can help me with the next step.
This is what I've done since the last post.

I've changed chips, no help
I've switched out ECM's, no help
I've replaced the TCC, no help.

I still get the tcc switching on and off at steady throttle when the tranny shifts into 3rd gear at ~32 mph. This only happens when the car is up to operating temp. Which would seem to be something electrical. If it was a ground tho., wouldn't it happen even if the car was not up to operating temp? B/c at operating temp. is when the ecm will allow the tcc to engage.

Anyone? This is sure aggravating

 

[nuc]

And the answer was...... after 2 new pressure switches, a tcc solenoid, 2 fluid changes , a new chip, a changed ecm, it was the VSS causing the ecm to think that the speed of the car was going up and down.

Thanks for the help tho.

I appreciate it

Adam