My 86 camaro has had a problem lately with shifting. When I am cruising around the 3 and for gear shifting points, or the torque converter is trying to lock, it keeps bouncing back and forth. It is somewhat intermittent and goes away if I keep it under load. Could this be the ecm? I also have had some difficult starting this winter and just recently, after a drive, when I put it in Park the rpms rev to 2k. If I shut it off and turn it back on it goes back to normal. I am getting codes:

13.Oxygen sensor signal stays lean during warm engine cruise
22.Low voltage at throttle positon sensor OR Fuel cutoff relay circuit open or shorted to ground

I have been trying to change the o2 sensor but can't get the stinkin thing unscrewed. I have done tests on the tps with the meter and the voltage climbs slowly like it should without spikes. I have been getting a good 5 volts and the other 2 wires are where they should be. This is getting frustrating, any ideas of what I should try next?

 

if you are pulling these codes, acording to what i have found about ajacent codes(15&21), your TC wont/shouldnt lock up causing the car to shift wierd. you might try clearing the codes/reset ecm. with big weather changes that seems to help me. also wd40 your throttle linkages your fast idle might be sticking causing the 2k idle problem. but if you have mpfi or tpi it could be ecm(i dont know my cars got a carb)

 

Thanks for the input!
I finally got my O2 sensor and put changed but it didn't help any. I also reset the ecm with no change.

Maybe someone out there would know; does the ecm control anything about the auto trans or is it completely controlled by the TV cable? I just need to know if this shifting problem is and transmission issue or if it could be related to the 2 service engine lights?

 

Also, I take it back. I just checked the codes and code 13 is gone now after changing the O2 sensor. Code 22 is still there and I keep checking the tps with the meter but can't find anything wrong with the voltage or the sensor. The code Light goes off and on a lot while driving though.

 

700r4s are controlled only by the TV cable. They have a torque converter lock up solenoid. That may be the problem and is a cheap fix. Just be careful getting on the gas if you have a shifting problem.

Check your fluid. It may be brown from age, that's ok but a fluid change is recommended. Wipe the fluid onto a paper towl or a rag and smell it. If it smells burnt that's the clutch pack going. If its black that's bad too and the transmission should be serviced by someone with experience.

Do you have any noticeable issues in other gears? How's your 1-2 shift? Firm still? Or mushier then it use to be? How many miles? How's reverse? Good? Shift it from reverse to first. If it takes longer then 1 second, something is failing and needs more investigating.

Sorry about all the questions but an automatic transmission can be hard to diagnose without ripping it apart and checking parts.

 

Thanks so much for the ideas I will try to answer some of these questions. I changed the fluid About 60k miles ago so it is getting ready for another change. It is slightly brown but still has some redness to it. No burnt smell. It has about 175k on it. I can't remember now.
The fluid level was about a pint high maybe but I just took some out today and have tested to see if it made a difference.

It is good but ever since I have had the car reverse has seems a little noisy to me. It has a slight whine to it and I am not sure if it is normal but it has gone strong for about 65 since I have had it. I will do the timed shift test tomorrow.

I sometimes wonder if I am interpreting which gear I am in correctly, but first to second and second to third are nice and firm. Does the torque converter only lock in 4th? Once I get to 40 mph it seems to lock, as I can see the tach drop. That is the last changed the trans makes and I am assuming that it is the torque converter locking into place. The problem happens when I am over 40, it locks, then if I continue to drive in the 45 to 60mph range it keeps hooping in and out. I will see the tach jump up, then it locks back down. It doesn't happen until it warms up and it seems to stop after I get above 65mph. It is very hit and miss, sometimes it is almost constant, and other times it barely does it at all. The peculiar thing is even when I shift out of OD into just drive, it still happens only it shifts into the next gear down.
Sorry if that was too much detail!

 

The whining doesn't sound healthy at all. It shouldn't be whining in reverse. Is it like a grinding whine or a high pitch whine? How's the 1-2 shift as the transmission uses the same procedure To Shift between the two except different input clutches are applied. If the 1-2 shift is fine then the whining is coming from the reverse input clutch and low reverse clutch or one of them. Again gutting is the only true diagnosis.

If you want to test your fluid pressure then you need a pressure gauge capable of 300 psi with a heavy duty hose and I believe its a 1/8 inch NPT fitting. If you plan to read the gauge in your car I recommend at least 7 foot of hose but 10 is gonna be the guarantee and what most specialists would recommend for reading any car/truck.

You will need to find your test port plug on your 700r4 which would be on your drivers side. I would recommend Jacking the car up and holding it securely in the air but its ok on the ground.

After you hook up your pressure gauge to the test port, start the car and let it reach operating temperature. After its at that temperature, apply the brake and hold it during all the tests. Shift into gear and slowly raise the engine rpm to 1000 then take note your pressure level (in psi). Do not take more then 20 seconds to record the pressure in one gear and do not take more then 2 minutes for all tests. This will result in transmission damage as you'll strave it for fluid.

In neutral you should be between 55 psi and 75 psi.
In low or 2nd you should be between 85 psi to 190 psi.
In drive you should be between 55 psi and 75 psi.
In reverse you should be between 85 psi to 140 psi.

Don't apologize for detail. It is good and helps troubleshot your transmission. But again gutting it is the only way to be sure. One stupid question. How's your TV cable? Is it adjusted right?

But 175k is a lot and unfortunately these transmissions were not built like they were in 97 and up (the 4l60e is the 700r4 but electronic. GM only made 4l60Es as of 93 I believe, no more 700r4s [of course not all transmissions but the nonelectronic ones were gone])but at this year all major problems were fixed from revisions and stock transmissions lasted much longer and healthier. I really hate to say it but your transmissiom has many worn parts at this point that could go out depending on how much you abuse it.

 

Yes, the 700R4 and ECM can lock the torque converter in 3rd. Generally around 30-35. Sometimes.

The reverse whine is troubling. However, 175K is NOT a lot. The only reason I ditched my 700R4 with 213K is because of this same torque converter issue. No noises, no problem shifts, nothing. And I did beat on it. It was still working when I sold it to another member on here (I went manual).

You might try a fluid change. Not with the "High Mileage" stuff. I'm talking with the Dexron VI or whatever the newest stuff is. It has friction modifiers in it the old ATF doesn't, to help the engagement of the clutch parts.

As for the TCC, I have always thought that, with mine, there might possibly be a clogged screen between the TCC and the solenoid. I do know there is a screen in the passage. It seemed to me that more and more boost pressure (from the TV boost source) was required to keep the TCC locked at higher trans temps (nothing like driving for a couple of hours and then having the trans jump out of TCC lock at 75!).

I would start with the TPS issue first. If the ECM isn't seeing a consistant signal from the TPS, it won't know to keep the TCC locked.

 

There isn't any whining with any of the other gears, just the reverse.
I ordered another tps in hopes that it will fix the 22 code. Yesterday I drove all the way from work(a half hour) and the light never came on, and coincidentally, no weird shifting. The reason why I had the thought that it might have something to do with the ecm and codes is I once had the identical problem with my 94 camaro. The problem then was I had broke the coolant temp sensor just enough that it's signal was cutting out off and on, which was making the ecm lock and unlock the tcc. I know that it was a newer system and might not be the same. But it seemed to be similar in nature.

 

Solved! I changed the tps. I also found out it the old one might not have been adjusted right, the manual says at idle it should read between .54 and .56, mine was at .68. Either way it fixed the code 22, the high idle, the hard starting and the shifting issues! The tcc hasn't jumped out once ever since the change and it has been a week. The tps problem must have been sending weird signals to the ecm that caused it to erratically lock and unlock the tcc. Such a relief to have it well again! I have dealt with this for over 3 months! Thanks for everyone's help!