My odyssey begins a year ago when I bought this 1990 sovereign. Because the head and block were corroded, I ended up having to buy a second engine via eBay. This all went pretty well and with some work I had a running car.
But… before I swapped the engines out I had a well running transmission too. It shifted smoothly through all the gears and I had no concerns about the transmission at all.
When I put the new used engine back in I what I found was I had done something to the transmission which had been previously fully functioning. Initially it seemed to be okay, then the drive started deteriorating. Basically when you give if gas, the transmission slips and you have to rev it above 3k to get it to move along.
Initially I put in Dex6 fluid and had some difficulties getting the amount right. What I realized later was that I had spilled a good chunk of fluid out of the torque converter and failed to replace it before reinstalling so the transmission. I’m not sure if these two points – wrong fluid and didn’t refill the TC – were the cause but they seemed to be the logical conclusion.
Eventually it started getting worse and I suspected that I had somehow ruined the torque converter. I switched out the Dex6 for Dex3 with a couple of swaps.
When I first took the original transmission out, I checked the pan and there was some sludge but nothing unusual for a 90,000 mile car. No filings or chunks, the fluid was acceptable ( but of course now I’m using fluid that has practically 0 miles on it.)
And I was still having slipping. I figured that I had to replace the torque converter, since I’m getting no power to the wheels. So I dropped the transmission, sourced a remanufactured torque converter and put it all back together again. Quite a job with no lift I might add.
While I had it out, I took off the valve body and didn’t find anything obviously amiss. No shavings, red fluid. I carefully put the valve body back together, but I didn’t actually test the solenoids.
I put everything back together, flushing the cooler and lines - now the car is reluctant to move at all. I can start it up and shift PRND but get very little movement forward or backward. it seems to me that there is no pressure being built up by the pump.
I’m pretty sure that I installed the torque converter correctly 3 clicks and it bolted right up to the flywheel and to the bell housing so I don’t know how I could have gotten that wrong during the install.
Now I find myself having to do the job all over again I think and perhaps just have the transmission rebuilt.
I really don’t have the time or inclination to rebuild the transmission myself I’d like to take it to someone and just get it done and done right quickly. That could be quite expensive the alternative would be to use a new donor transmission and also hope for the best.
There is one on eBay now that I’m considering but it is for a 93-94 model year. I thought all of the ZFH HP24 would be the same from model year to the next from 90 to 94. Does anyone know why 93-94 would be different from 90 to 92?
So I find myself in a situation where I have a perfectly tuned and running engine and no way to get this car moving forward.
Tl;dr After replacing a torque converter my car won’t move forward - what are my options to try to fix it and would a 93-94 work as a replacement transmission?
Thanks in advance.
JitneyBead
I have a feeling I read something about the transmission differences but can’t remember the details - I know that isn’t much help, but looking at the parts catalog I see that up to VIN 614440, EBC3541E is the part # while from VIN 614441, the part number quoted is EBC4409E.
The EBC3541E is listed as NLA.
From what i can see, If you already had the electronically-controlled ZF 4HP24 with Sport Mode, you’ll be fine with the 93-94 trans.
Well… yay… and … boo!
Fluid level fluid level fluid level.
I rechecked how much I put into the transmission after the TC replacement and realized I was 4 quarts low from capacity. Dumb dumb move but at least I now have a driving car. Sort of…
Now I have the problem of a low rpm stall speed … without giving it some gas it will stall out and quit. So I have to hit the gas and brake and while I shift to get the RPMs up and then take off. Seems to shift perfectly otherwise. Coming up to a stop I have to put it in neutral or it will stall and quit.
Does my new TC need to be “broken in”? Is it possible that there are more than one TCs with different stall speeds and I’ve got the wrong one? What adjustments can I do, if any, to increase the idle speed at a standstill in D and R?
The TPS sensor under the throttle has been cleaned and checked when I had the engine our last summer - not saying it can’t be that, but I doubt it… Of course I swore I had the right amount of fluid in it too.
Thoughts, ideas, suggestions?
I’ll chase that next, but wouldn’t a bad TPS pot impact idle in Park and Neutral? Because idling in Park and Neutral is spot on around 900, no different than before I swapped out the TC. When putting it in R/D we introduce a load without a change at the throttle, should the ECU compensate?
As you noted PARK n NEUTRAL have no load adn reliable idle is set by mechanical butterfly opening… under load… trany in DRIVE etc the ICM is a must to compensate… if ICM Throttle motor is sticking or TPS sensor is noisy or soso the ECU can not compensate for the load and stalling occurs… be sure your trany warm and on level ground has correct level but sounds like this used engine has some ICM idle control motor issues… maybe run a test …I’ve bench tested them but youd need a dignal generator to get the motor to extend and retract the shaft… if its sticky or even jams oh yeah it is the idle control circuit for loads and car will stall for sure… TPS could also be an issue but without tests and seeing car in person id put money on the ICM… i got a spare at rockauto for 45 dollars some years ago
yes and check all the sensor connections air intake ones and TPS and ICM do connections look clean? maybe spray with silicone or other electronic cleaner… Deoxit is a decent product… so it could be a loose or partially shorted connector
But if all those wires are from your old engine and that worked good id be less suspicious of the wires *id check em anyway) and check that ICM motor that is the holy grail of idle compensation and that is what you need under load
When putting it in R/D we introduce a load without a change at the throttle, should the ECU compensate?