Transmission issue

[94SCparkavenue]

I let a friend borrow my car (NEVER AGAIN) and he was going down 95 he said he was doing like 112 Est. and it started jerking. well he slowed down and i havnt had overdrive since. i thought it was the trans. so i changed it. still having the same problem. is there anything else it can be ? TIA

[spoiledred94]

Just shots in the dark: Fluid level? If you pull the trans oil output line from the lower right radiator and turn it over for a few seconds you should have flow out of that pipe. If not then it could be your trans oil pump inside the trans. Also 1) check your fuse panel. A TCC circuit runs through the fuse panel. Happened to mine and the trans would not engage at all. 2)Of course you should check the trans/harness electrical connections too.

Other than stuff like that I guess you have to prepare for more trans work.

[94SCparkavenue]

I put a different transmission in it yesterday and still have the same issue.

[myfirstbonnie]

Do you have a check engine light? Do you have a tachometer in the dash? if so, at 55 mph, what rpm's are you at? It might not be overdrive you are missing, it could be torque converter lock up.

What is it doing to make you feel like the overdrive (4th gear) is not working. You can always count the shifts when accelerating slowly.

Get the car going 55mph and hold it steady, while maintaining speed with the accelerator, just tap the brake pedal and see if the engine feels like it rev'd up a little. If it doesn't, that means the torque converter clutch (TCC) is not engaging.

[bonnevillain]

The PCM will also prevent you from entering OD if it detects a certain amount of slip.. my 95 had this problem periodically, and a restart would sometimes fix it.
It is possible you got a trans with a bad 4th shaft or TCC. I'm assuming it was used?

[94SCparkavenue]

Yes the trans is used but I drove the car that it came out of before we pulled it and it was perfect. I kno at 70 it sits at 3k rpm. And I have counted the shifts. It shifts 3 times... Same as old trans. Also no matter what speed if I go to accelerate it won't down shift. And some times when I am taking off it won't go above 3k rpms. Same as old transmission...

[spoiledred94]

I swapped in another transmission because mine was slipping. Stopped the slip but, then a 1000 mi later the new used trans just quit all toghether . I'm just saying a used trans form the mid 90's isn't likely to have a lot of legs left in it.

[myfirstbonnie]

Ok, if it shifts 3 times, that is correct....
1. 1-2 shift
2. 2-3 shift
3. 3-4th (overdrive) shift

Is there a check engine light on? Does this model and year (94 Park Ave) have the vacuum modulator on the tranny and the TV cable?

[94SCparkavenue]

The used trans has 76000 miles on it. It shifts twice.(My bad) I will be doing 60 mph pull it from drive to 3 and it makes no change what so ever .yes it has the modulator. Tv cable? When it had od I would be going down i95 at 70 and the rpms sit at abt 2k now it sits at 3k and when I let off the accelerator and push it back the motor revs up to about 3 k till it catches so I kno that od osnt working but I just can't figure out why.

[myfirstbonnie]

Did you adjust the TV cable?


Any check engine (service engine soon) light?

[94SCparkavenue]

There is a ses light. Don't hace a scanner. Took. It to advance auto to have them scan it. And it comes up that the plug is bad... I have had the same guy scan my car before. A tv cable?.

[myfirstbonnie]

You don't have a bad connector, read this:http://www.pontiacbonnevilleclub.com/fo ... =51&t=1638

Right now the first thing would be to find what codes are set. The TV cable is the cable that connects to the throttle and goes into the transmission, but right now we need to get your codes read.

From what I have found, you should have the 4T60-E transmission that is controlled by the PCM and does not have a TV cable.

[94SCparkavenue]

Ya I understand all of that but why would it work before and not now?

[myfirstbonnie]

Have you tried another shop? I am not real familiar with the OBD 1.5 to be able to say you were even getting the correct information in the past.

I do know that you eliminated the transmission as the problem and with the SES light we know there are codes for problems the PCM recognizes. It will help a lot and save time and money.

Was the SES light on before you had this issue?

[94SCparkavenue]

Yes the ses light has been on for a long time

[myfirstbonnie]

Right now without seeing the codes, I would suggest checking the throttle position sensor (TPS).

Where are you located? I would really like to get the codes pulled to help you a lot better.

[94SCparkavenue]

Florida. And I had the engine running and unplugged the tps sensor and there was no change in the way he engine was running

[myfirstbonnie]

Ok, reading my FSM it states there are certain situations that the TPS will cause no TCC lock-up, no 4th gear and no cruise control.

This is why we need the codes to see what the PCM is seeing faulty.

Do you have access to a multimeter to check the TPS? It should be .2 to .74 volts at idle and over 4 volts at WOT. It should also be a smooth transition.

[94SCparkavenue]

Ill see if I can get access to one

[bonnevillain]

They're $5-$10. it would be a good investment.