trans Q

idrivejunk · June 14, 2020, 08:48:41 AM

Got my 99 Pontiac Grand Prix GTP back from a transmission rebuild Thursday. Now, in light uphill scenarios at steady throttle, it "hunts". Seems like the converter is locking and unlocking constantly in that situation, which is I believe in third. 30-45 MPH. Right where 95% of usage is.

4T65E-HD trans, supercharged 3800 V6. Stock.

The question is before I take it back, can a faulty MAF or other problem cause it to hunt?

Initially, it would shudder and give a short rumble strip feeling after a couple up and downs of about 100 RPM. Replaced battery, plugs, wires, coils. Now it doesn't do the lug and stumble thing but the issue is obvious and constant.

I am supposed to return to trans shop next Friday for a visual fluid leak and level check for warranty purposes.

Do I drop it off today (have to walk 3 mi) so its on their doorstep Monday with "bad converter" noted? It just got a new converter.

Anyone care to confuse me further, debunk, or clarify? I am lost. If there was a carb and distributor I'd already be sure. Dad solved this crap on his Citation by putting TC lockup on a switch under the dash.

:?

kb426 · June 14, 2020, 01:22:02 PM

Is there a chance the ecu has to relearn the parameters for driving?

idrivejunk · June 14, 2020, 01:48:09 PM

Quote from: "kb426"Is there a chance the ecu has to relearn the parameters for driving?

I don't know if it adapts or if it learns at all. The ECU does have a "canned" tune which alters shift times. But the issue seems constant, not improving.

Not fifty miles on it yet, probably haven't had it up past 60. More driving, you think?

kb426 · June 14, 2020, 03:35:13 PM

I found this page. Most anybody knows more than me about that trans.

https://tripleedgeperformance.com/4T65E-Common-Problems.html

idrivejunk · June 14, 2020, 05:22:22 PM

Oh boy, that was an interesting paragraph on TCC rpm oscillation.

I have one ABS wheels sensor unplugged to defeat ABS. Which in turn turns off traction control. Wonder if I ought to plug that in. Hmm.

I was thinking maybe I should go get it up on a few exits worth of interstate. Now I am thinking I should drop it off with the key. :?

Thats probably the safe move, stay out of it and call them tomorrow. Neato!

idrivejunk · June 14, 2020, 06:04:36 PM

I connected my bluetooth adapter and used Torque on my ancient tablet and had a peek at what the MAF is doing.

It looks very normal to me. Trans man can check the car out as-is but it sounds like more lift time. Yep.

idrivejunk · June 16, 2020, 11:12:33 PM

Trans shop called today, they picked up the car yesterday. They are overnighting some "internal electronic pieces", "as a start". I would guess the TCC solenoid or whatever is one. Mood, hopeful.

I am glad I am not them.

idrivejunk · June 19, 2020, 07:30:59 PM

Had the wrong torque converter in it. They had ordered it off the # on the converter on the '02 trans. 99 and 02 stall speed is different. Shop was able to swap out converters with their supplier somehow. But once they had built it to 99 spec, the 02 converter was wrong. Seems fixed now but only drove it 3 miles. Feels like they didn't tighten the intermediate shaft. Back to the jackstands.

idrivejunk · July 04, 2020, 03:13:38 PM

Reckon this thread ought to have a wrap-up. This is it. Steering slop amount was merely forgotten in 4 months. I remember now. GT has 100K less miles on it and I was driving it. Don't like the slop on the GTP but it was and is there and I am back comfortable with it again.