GN Acts Odd After Highway Driving...

[231power]

Hello - I'm looking for some insight on a problem - starting last summer, if I drive at highway speed for at least say, 10 to 20 min, then slow down to city driving, the GN acts erratic. It feels like the tranny is acting up, but of course that isn’t always the cause. If I tap the gas, it acts like it’s in 2nd gear and will jerk the car (TCC?) . I get a bit of that ‘fishbiting’ feel, and if I try to accelerate, the kick down isn’t where I am used to feeling it (seems to bog a bit and then kick down more abruptly. )
If the car sits for a while and cools off, it’s back to normal and I can drive in the city with no issues – it’s only once I’m at highway speed and then switch to city that it shows up. (I had the tranny fluid flushed last summer, I think after this problem started)

Another new thing since I got it out this April is some feedback I’m getting from the brake petal when stopped – not all the time, it comes and goes and just seems present when the car isn’t actually moving – and I see the brake lights are flickering in time with the pulse from the petal. I’ve had good luck with the car over the past 13 years – I think the only brake part I had to replace was the black accumulator that screws on horizontally (if I’m remembering the part name right).

Any thoughts from the experts would be greatly appreciated!
I lost the only mechanic around here who had some GN experience.

 

[84TXGN]

sounds like the torque convetor lock-up solenoid is sticking. I would replace it. Also, if you don't already have one, get a good external tranny cooler.

 

[Matt McClung]

sounds like the torque convetor lock-up solenoid is sticking. I would replace it. Also, if you don't already have one, get a good external tranny cooler.

ditto to the above, it is without a doubt the lock up solenoid for the torque convertor.


Matt

 

[231power]

Test Drive

Thanks for the replies - I had a tranny shop owner go for a test drive with me today - he was pretty surprised with the torque conv. at around 50mph - he said it was doing the opposite to what it should (he'd tap the brake and see the rpm's go up rather than down I think)

Scan tool didn't reveal any codes.
He said I could unplug the wire harness from the driver's side for the torque conv., and if it didn't do it then, he believes the torque conv. would be the issue. I unplugged it, went for a 40 mile highway run and it did not act up afterward.

So I'll pitch to him to rule out the TC lock up solenoid first - make sense? Is the solenoid replacement an expensive job ?

Oh, any thoughts on what I'm seeing with the brake petal feedback?
Thanks for any info - much appreciated!

 

[84TXGN]

Thanks for the replies - I had a tranny shop owner go for a test drive with me today - he was pretty surprised with the torque conv. at around 50mph - he said it was doing the opposite to what it should (he'd tap the brake and see the rpm's go up rather than down I think)

Scan tool didn't reveal any codes.
He said I could unplug the wire harness from the driver's side for the torque conv., and if it didn't do it then, he believes the torque conv. would be the issue. I unplugged it, went for a 40 mile highway run and it did not act up afterward.

So I'll pitch to him to rule out the TC lock up solenoid first - make sense? Is the solenoid replacement an expensive job ?

Oh, any thoughts on what I'm seeing with the brake petal feedback?
Thanks for any info - much appreciated!

The solenoid is easy to do, just drop the tranny pan and its right there on the valve body. There are 2 bolts holding it in. Just unbolt it, cut the wires, splice the wires with the new solenoid and bolt it back up. Fill with fluid and you are good to go.

 

[Quick6'n'-K.C.]

Its the TCC solenoid sticking, replace it and be done with it.

BW

 

[231power]

Hey all, well I finally got the GN into the tranny shop for a look at this 'jerking after a highway drive issue' - the Powermaster brake system kinda blew up in the meantime and I got that fixed up this weekend.

The tranny shop owner took out the TC lock up solenoid and bench tested it and says it working great and would be a waste to replace it. He's seeing some 'clutch material' on the magnet in the pan, also since I didn't see the problem when I had the wires unplugged to the TC, he's back to thinking I have a converter problem (about 5 x the cost). He asked to see the specs on the Jay Carter chip I had installed years ago, as I told him I thought it changed the TC lockup properties a bit. I doubt there's anything too surprising there though.

Any thoughts if the converter is the right path to be on?? Thanks for any info!

 

[RUQWKNF27]

I had the same problem an it was the solenoid..!!! He says its good well maybe he's right.. But yesterday I went to Autozone an they said my module was good then went to Oreilys an they said it was bad. Then I went to Advance Auto an bought one an now my car is fine.. Personally I would replace the TCC an make sure the convertor locks up an all before I went an spent a bunch of money..

 

[Quick6]

If you are gonna go to the trouble of dropping the pan and pulling the TCC solenoid to test it....then just put a new one back in. Testing it on the bench at room temp is not the same as in fluid at 200+degrees.

 

[wagon]

Tell them to put a new solenoid in, put in a new filter put on the pan and refill it. Tell them you want the old one just to make sure they do it. Then drive the car and see if everyone is right. I'm betting it is. Then find a new tranny shop. Of course there will be something in the pan if it isn't a brand new tranny, I wouldn't worry about it unless there is a lot of stuff of there were big pieces in there.

 

[Quick6'n'-K.C.]

Its the TCC solenoid sticking, replace it and be done with it.

BW

Follow that guys advice and find a new tranny guy.

I have seen countless turbo regals with this issue, do a search on this board and you will find its the TCC solenoid.

There is nothing wrong with your convertor, there is nothing wrong with clutch material in the bottom of the trans pan.. Its normal wear and tear.

BW

 

[231power]

Solenoid hit the spot! Didn't mean to sound like a doubter - when the shop said the part bench tested fine, I had no idea that it would still be defective.
Thanks gents....

 

[Quick6'n'-K.C.]

Glad you posted back and let us know how it turned out, i post alot and 80% never get back to let me know.

Anything else wrong with the car?

BW

 

[1970gsx]

Solenoid hit the spot! Didn't mean to sound like a doubter - when the shop said the part bench tested fine, I had no idea that it would still be defective.
Thanks gents....

Of course it was! It sounds like your tranny guy felt like making $1800 instead of $75. I would find a more trustworthy tranny guy.

 

[231power]

Other problems? Well, I did do a complete powermaster replacement just before the tranny work - got a rebuilt unit from 'Turbo27' in the forum here.

When we put power to it, there was fluid escaping around the pressure switch - had to give it a 1/4" turn, it's still just a little bit wet at the threads - I'll have to check my original PM unit for the O ring and try moving it to the new one.

And I know my ears are tuned in to the pump sound now, but it seems to be running on every 3rd petal push at the most.... or after just 2. And it seems to stop with a more audible click than what I was used to. I think we did a good job of bleeding the system - my mechanic followed the procedures I printed out as I'd warned him it's a little trickier than some... We let some brake fluid sit in there for a while, then bled the frt/rear connections to the Mas Cylinder, and bled at each wheel in the right order. Maybe I'll still need to do the troubleshooting flow chart to verify the accumulator? Thanks!