Are my "rpms" too high?

[Sams01XplrSprt]

welcome

 

[Gadget X]

You're torque converter is definitely not locking up. It's like you are constantly in "passing gear". This is what my 94' looks like stock at 70 mph. The engine is only turning about 2K.

 

[1Byounkin]

how can I make the torque converter to lockup? The torque converter is only a year old and the transmission has been rebuilt but never locked up. Here is how my speed is at a constant speed (not speeding up or down).

Any ideas?

 

[North_Pole_Guy]

same rpm problem

greetings,
i too am having the same problem, i just pulled the transmission on my 1991 to replace the converter pump seal and am now having the same problems. did you ever find a resolution to your issue? i am wondering if the plug that connects to the transmission that controls the converter lockup is flakey?
is that the plug that goes into the top side of the transmission? it is rather hard to get to. i had adjusted the bands and that seemed to help a little, it shifts hard through third gear from a dead stop with firm shifts then feels like it shifts into od but the rpm's at 60 are like 2,600-2,800, seems a little high and i don't feel a (bump) when the converter should be locking up.
any thoughts?

 

[North_Pole_Guy]

No OD overdrive lock up

Ok so after much reading and determining that it could be alot of things and some included pulling the transmission again which I did not want to do. So I got out a handfull of chicken bones shook them in one hand and threw them down onto the shop floor it looked as though I should read the codes and they said code 22 MAP sensor out of range, now this could not possibly be related to the OD not locking up I am convinced that the OD solenoid is the culpret. So off to town I go to locate a new MAP sensor ( has to be changed to clear the check engine light anyhow) and an OD lockup solenoid. So I could only find the MAP sensor local the OD solenoid was some where back east and even the local ford dealer had none and wanted twice the price anyhow. So I went home with my new MAP sensor to replace the one that checked bad ( found it's location by reading another thread) thanks. So now I changed out he sensor and back to the chicken bones, tossed them across the garage floor again and they looked favorable so now for a test drive, well now it shifts through all the gears and even locks up the torque converter. So was it the MAP sensor or the chicken bones? My library transmission book that I read after the fact says that the MAP sensor can cause the torque converter to not lock up, how are they related? Well thanks to all of you for the very helpful posts. Anyone not experiancing a torque converter not locking up should check that MAP sensor before they tear into the transmission.

 

[Maniak]

To make sure its not going into lockup.. Get up to speed again and while cruising with a light throttle "touch" the brakes. Don't hit the brakes to slow down, touch the brakes to basically turn off the cruise control (I know, its not on)...

If the RPM's jump then the converter was locked up. If it doesn't jump then you are in 4th gear but with no lockup..

The A4ld transmission is electrically inhibited from going into 4th gear and from locking up the converter. That means unless it is told otherwise the transmission wants to go into 4 and OD.

There are 2 solenoids in the transmission. TCC and the 3/4 solenoid. The computer sends a ground signal (it does NOT ground the wire) which then kicks the solenoid which then lets the transmission shift to 4 and/or lockup the converter.

On the side of the transmission (drivers side) you have 2 connections. One is for the shifter (reverse lights, neutral safety switch etc) and the other is for the tcc and 3/4. On the Tcc and 3/4 connector there is a red wire there that should have 12 volts on it (compared to ground). If you somehow probe/watch the signal between that red wire that has 12 volts and each signal wire (the other 2 wires) you will see it go from 0 volts to 12v difference when the computer tells it to shift to 4th or when it says to lockup the converter depending on which wire your watching.

The wires run near the exhaust manifold and onto/around the drivers fenderwell. If you lose the factory harness clips the harness can land against the exhaust manifold and it will melt a wire which can cause it not to go into 4th or get TCC lockup.

I hope that gets you pointed in the right direction..

If you find you have the signal on the wires telling the trans to shift/lockup and its not then you have an internal issue. The Tcc and 3/4 solenoids are in the valve body which has to be removed to change the solenoids.

~Mark

 

[Gadget X]

Glacier991, BrooklynBay, Maniak, any of you tranny (not that kind!) gurus know what's going on in relation to the MAP sensor North Pole Guy spoke of? I'm curious!

 

[Maniak]

As I see it, since the lockup is electronically inhibited, if the computer doesn't think your cruising under a light throttle it won't lock the converter. On the 91's the MAP sensor is what is uses to know how far you have the throttle open. If it thinks you are lugging the motor possibly just because it cant read the sensor the ECM may not lockup the converter.

~Mark

 

[North_Pole_Guy]

OD locks up fine now

Well with several test drives now I can say that the TCC is locking up. At 55 mph with foot on throttle if you touch the brakes with the left foot the engine speeds up a few hundred rpm's. Currently at 55 mph it is at 2,400 rpm's, the door sticker has an axle code of D4. I have no experiance driving this car before the brakedown it is my brothers car. My brother did a little looking and it sounds like this is about the right rpm for this gearset, any one have any input as to what they are running?

 

[1Byounkin]

I'm with North_Pole_Guy, Yes it does unlock if you tap the pedel while traveling and it will go into the "passing gear". I drive around all the time. I still run 3000 rpms at 65mph. I noticed that when I changed the stock air box my rpms drop alittle. Might do a bigger MAF housing. My speed is 5 miles off, i think. Could the gearset be off? It could been changed before I had it. Shift points are great. So 65mph - 3000rpms 55mph - 2500rpms.

 

[1Byounkin]

It had been covered before in this thread, but could the MAP sensor be going bad. If the MAP tells the computer to tell the transmission to lock up and it's not locking fully. Could this be it?

 

[North_Pole_Guy]

Bad MAP

I did have a bad map sensor and it did in fact prevent the torque converter from locking up. Once changed the TC did in fact lock up. I just got through rebuilding the valve body also, had a few sticky valves. Hope to test drive it Monday and let you know what has happened

 

[backfrmcolorado]

What gearing do you have. My buddy has a 93 ranger with a 4.0 and same trans and his is the same way... kinda sound like you may have 4:10 gearing to me. i can cruise at 80-85 at 3000 rpms in my 94 with 3:73 gears. There is a small sticker in the passenger side ibeam of the front end that has the gearing specs of the front end and would be the same for the rear. Check it out b4 you jump to conclusios about the trans. higher gearing will cause higher rpms at hight speeds.

 

[1Byounkin]

I did have a bad map sensor and it did in fact prevent the torque converter from locking up. Once changed the TC did in fact lock up. I just got through rebuilding the valve body also, had a few sticky valves. Hope to test drive it Monday and let you know what has happened

If I can finded a used one that I'll try that. My Gear set is going to be good. Before I got the transmission rebuilt the rpms where good.

 

[BrooklynBay]

Your thread was moved into the stock 91-94 section.

 

[1Byounkin]

Ok so after much reading and determining that it could be alot of things and some included pulling the transmission again which I did not want to do. So I got out a handfull of chicken bones shook them in one hand and threw them down onto the shop floor it looked as though I should read the codes and they said code 22 MAP sensor out of range, now this could not possibly be related to the OD not locking up I am convinced that the OD solenoid is the culpret. So off to town I go to locate a new MAP sensor ( has to be changed to clear the check engine light anyhow) and an OD lockup solenoid. So I could only find the MAP sensor local the OD solenoid was some where back east and even the local ford dealer had none and wanted twice the price anyhow. So I went home with my new MAP sensor to replace the one that checked bad ( found it's location by reading another thread) thanks. So now I changed out he sensor and back to the chicken bones, tossed them across the garage floor again and they looked favorable so now for a test drive, well now it shifts through all the gears and even locks up the torque converter. So was it the MAP sensor or the chicken bones? My library transmission book that I read after the fact says that the MAP sensor can cause the torque converter to not lock up, how are they related? Well thanks to all of you for the very helpful posts. Anyone not experiancing a torque converter not locking up should check that MAP sensor before they tear into the transmission.

Did you get a check engine light for this code or just checked. How would I know if the MAP sensor would make mine not lock up, if it is not the MAP sensor. Any way of checking

 

[North_Pole_Guy]

MAP sensor code and TCC not locking up

Well I did have a check engine light and it did code out as a MAP sensor. So if you have that code it is probably the culprit. If you had a spare sensor it might be worth trying. Another post I read said to check the wire harness on the drivers side fire wall. It runs next to the exhaust system and sometimes gets melted and shorts either intermittently or hard fault. The wires for the transmission run in this loom so any defect could cause problems with shifting neutral safety switch or the TCC lockup.

Will know more about mine tomorrow after a test drive.

 

[1Byounkin]

I'll wait to do the MAP sensor until I get one to try from pull a parts. I believe I will try to clean the valve body. The first two days the transmission was built it did great. But after while some of the stuff in the transmission started to stick up and not drive. After they free all the parts this is where is notice the higher rpms at 65 mph. I know a guy that could rebuilt the valve body. What I think it's doing is that the solenoid is kick in but not all of the fluid is moving in the valve body to the last gear (4th).

So you had the same problem with the rpms high (3000rpms at 65mph), but all the other gears shift great.

 

[North_Pole_Guy]

Eratic shifting

Nope had strange shifting in all ranges but that was due to some other sticking valves in the valvebody. The no lock up in OD was the MAP sensor I am thinking. What is it that you are seeing with your ride?

 

[1Byounkin]

I still have this problem with the high rpms. I've checked many sensors that communicate to the computer for the transmission. I've been reading on this page: http://www.explorerforum.com/forums//archive/index.php/t-53593.html . There is some talk of people replacing the ECT (Coolant Temperature Sensor) that would make the computer think the engine is still cold. So the computer would not tell the 4th OD to lockup because it was to cold.


I'm still going to check the EEC and check the wires. Also see if it is sending 12v to the transmission for the OD.

Remember the TCC locks up good, just will not go into 4th OD.

Has anyone changed the ECT and made OD to start working?