Crusherfied

iTrader: (2)

Ever since I swapped in the 5.7 and the 700R4, the torque converter won't lock. Also, when the engine is warm, shifting from park or neutral into any gear, there will be an rpm slow down, even to the point of stalling. Otherwise, shifting seems normal.

The trans was rebuilt sometime in the past and was flushed about 20,000kms ago. But the donor car sat under a tree for about 6 years in our all weather climate.

So the other day I thought I would try out SeaFoams Trans Tune. I drove the car to warm up the tranny fluid first, then added about half a can as per instructions, then continued driving for a bit, shifting through all gears. I even did a lengthy reverse backup on a quiet back road, about 1/4 mile. After the backup, I continued on my drive, immediatley going down a very steep downhill, then leveling out on a nice country back road. That's when it happened, the torque converter locked up for the very first time since the swap. At the same time I got a check engine light that would come on for 15 seconds or so then turn off, then turn on again a minute later and then turn off. This continued for the rest of the drive. I drove for another 10 minutes or so with the trans locking up nicely.

I stopped in at my cousins and had about a 30 minute visit. When I got back in the car and drove home, the trans would not lockup anymore. I tried the jumper wire diagnostic to see what code was stored, but no codes were given, my check engine light only gave two quick flashes and then nothing. I have driven it several times this week with no change of the TC and no check engine light lighting. Yesterday I siphoned a litre of tranny fluid out, it was a little full, and added another can of Trans Tune and went for a good drive. Good shifting still, but no lockup.

Short of pulling the trans out I don't know what to do other than a full flush and fillter. What do y'all think is going on and what should I do???

vetteoz

iTrader: (13)

https://www.thirdgen.org/forums/tech...formation.html



From what ?
A little history ( not your life history ) goes a long way to helping background a problem and ESP doesn't work well over the web

There are no codes for non working TCC.

Was the lockup working correctly in that trans before the swap ?

Have you done the basics like check the TCC wiring through the brake switch to the plug on the trans to see if anything is faulty ,
possibly giving a intermittent fault?

Crusherfied

iTrader: (2)

History: Donor car 1987 Iroc 5.7L TPI, 700R4. Was a low mileage care that was well taken care off. Minor accident to front right corner of car prevented it from going back on the road. Tranny worked good in it. However, just learned recently that the previous owners (my cousins) younger brothers would secretly go out the car in the middle of winter, fire it up cold, pedal to the metal in reverse, then into drive, and do smoke shows on a rock. Thanks for telling me now cousins, would've been nice to have that info before I bought the car.

The car that received the goods: a 1987 Iroc 5.0L TPI with 5 speed. I bought this car without the engine, the engine wire harness and ECM, and without the tranny.

I swapped over the motor, trans, ecm, engine harness, speedo cluster, center consul and various other cosmetic items. I removed the clutch pedal, but made sure the switch on clutch stays engaged as if the pedal were still there. I've got the shifter lead to the ecm wired in. I've got another wire going from the shifter to the brake switch, and another from the brake switch to the tranny (I installed a proper auto brake switch). The other two wires from the 3 that are going to/from the TCC are part of the engine harness....so I believe that all appropriate wires are connected. I don't have all the other shifter switch wires connected however (the ground is connected though) but I understand they are for lights and such. I can however start the car in any gear. The engine also runs very rich...I searched for a vacuum leak and repaired some lines but the problem still persists...maybe still yet to find a leak.

The fact that the t.c. actually locked and worked right for 10 minutes or so with some stop and go and highway driving has given me some hope that everything is connected properly, and I mean it worked and felt great and perfectly normal, but just for that one drive. Also wondering why the check engine light came on the very second the torque converter locked? This has been a huge learning curve for me, so it's possible I've overlooked something simple and or critical. OR...the tranny is screwed.

Crusherfied

iTrader: (2)

Another thing that is happening is that the electric cooling fan is always on. Wonder if that is keeping the tranny temps too low???

I remember driving my 1994 Dodge Cummins with an auto trans. The torque converter wouldn't lock until you drove a few miles down the road, was even worse on cold winter days. But that trans was crap anyways.

Just makes me wonder if I have TC damage of some sort in the Camaro. I had some Jiffy Lube shop guys take it for a test drive the other day, and they said the engine rpm hesitation when shifting from park/neutral into gear is indicative of a torque converter problem, late shifting they said.

TreeFiddy

Maybe your tranny has a temp switch in the internal solenoid wiring, only allowing locking when the trans fluid temp is up. Which a 1/4 mile haul in reverse probably did.

vetteoz

iTrader: (13)

Not tranny related but pull the codes to see what caused the light
Might explain the rich condition

https://www.thirdgen.org/forums/tech...s-dumbies.html

Crusherfied

iTrader: (2)

Thanks, but like I said in the original post, I already tried to pull the stored codes, except I got nothing, not even a code 12...just two quick flashes and then a solid light.

Crusherfied

iTrader: (2)

Interesting, that could explain a whole bunch. Since the electric cooling fan is always running, the tranny fluid may never get warm enough to trip the switch.

I have to take a look at the engine temp sender too. The temp gauge in the cluster doesn't register except when I start the car, during start it goes all the way up to max and then once started crashes back down to nothing and stays there. Would this cause the fan to run continually though?

vetteoz

iTrader: (13)

That would suggest a ECM problem.
By default ,if the ECM has problems it goes into "Limp Home " mode and the fan runs as soon as you turn the key on.
Check the memcal ( chip ) in the ECM is correctly seated

Crusherfied

iTrader: (2)

Ok, I'll check into that. "Limp Home" would also cause the running rich issue too would it not? Thought I read that somewhere sometime. Just for the record, my fan doesn't turn on until the engine is started though.

Crusherfied

iTrader: (2)

So I was finally able to find time to pull the ECM. Everything looked and felt like it was seated properly. The sticker on the ECM did say that it was a GM re-manufactured unit though. My Haynes manual also said that the service # on the sticker should match the prom #. As you can see in the pics, no numbers match, unless I'm looking at the wrong parts.

vetteoz

iTrader: (13)

You know the Haynes manuals are recommended for use in the toilet and not as reading material don't you .............

The service number on the ECM has no relationship to the ID ( the BCC ) on the memcal
Your '165 ECM was used in different cars ; the programming on the memcal determines what combo it is set up for.
Changing the memcal allows the ECM to be used for a different setup ; as done with a 305 to 350 swap

The ABWN code on your memcal identifies it as '87 F-Body 350 auto tune

Crusherfied

iTrader: (2)

Ok, thats exactly what it should be then.

Ya, I've noticed this Haynes manual isn't very good on certain things. I'm a Toyota 4x4 guy and my Haynes manuals for them are pretty spot on, but for this car I've now found 3 different things in the manual that are incorrect or a bit off. For instance, when I was under the dash pulling the ECM, I discovered my heater core is leaking, so I also started to pull it. Six screws later and it is out. I checked the manual anyways to see what they said and they have you pulling off the dash pad, removing the speakers and brackets, disconecting the ductwork, dropping the steering column, pulling the stereo, moving the shifter, basically removing the whole dash to get at the core.

vetteoz

iTrader: (13)

For Vettes and F-Bodies at least ,they tend to be too generic, good for finding your way around the car but not for troubleshooting.

Only the FSM has a whole section devoted to the electrical system with detailed diagrams of every circuit in the car along with diagnostics flowcharts to pinpoint a problem
Almost essential to own a FSM if doing your own work

Crusherfied

iTrader: (2)

Ok, so I discovered tonight why my temp gauge wasn't working, the wire wasn't connected to it. So I reconnected and went for a good drive. I got a consistent gauge reading of around 75 degrees.

During my drive, the torque converter started locking again after about 10 to 15 minutes in. So I continued on for an extra long drive this time. Everything felt good in all gears. Kinda makes me think TreeFiddy is on to something about the trans fluid needing to get up to temp for the TC to work.

Also, once the TC starter working, the car no longer wanted to stall when shifting from park/neutral/drive/reverse. As soon as I put it into gear there was no hesitation and it was ready to go. It seemed like the car wasn't running as rich anymore either.

The check engine light came on four different times too. On the 4th time I immediately pulled over and turned the car off before the light went out. I put the jumper wire in the diagnostic and turned the key to on, but I still only got the two quick flashes and then a steady light, so no change there.

About the cooling fan, I should probably explain something I did during the swap, this might help give a clue to the continual running, I don't know. The donor car I got the engine/tranny from had air conditioning with the tranny cooler in the rad and the twin fan setup. The car that recieved the goods did not have air conditioning. So when I swapped everything, I deleted the A/C components from the engine. But, I did swap the rad/tranny cooler and the twin fans. I didn't know it at the time, but someone recently told me that with dual fans, one fan cools the engine, and the other fan only comes on when the A/C is turned on. Soooo, only one fan ever turns on, it's the driver side one, that continually runs, while the passenger side fan never turns on.............Is it possible that the fan that always runs is the A/C fan???? Is it somehow coming on due to my deletion of the A/C stuff??? And since it is always running and cooling, then the other fan never actually needs to turn on except maybe if engine temps really get high enough. Just wondering. I didn't swap the dash HVAC controls either if that makes a difference.

Crusherfied

iTrader: (2)

No thoughts from anybody???

I'm taking the car in for a complete flush and filter change of the tranny on Tuesday.

vetteoz

iTrader: (13)

How did you wire up the twin fans to your stock wiring?
What wiring / relays did you use ?

On a dual fan setup , one fan is for the engine , the other for the A/c and the ECM will run both together if the temp goes too high.

By default the A/c fan will run as soon as the A/c is turned on at any temp , so if the switch that operates it is not connected or bypassed ,that fan will run as soon as the key is tuned on.

Crusherfied

iTrader: (2)

The under hood wiring and relays all came over from the donor car, so I hooked up the fans just the way they were in the donor car. However, the under dash wiring did not get swapped, so there isn't any A/C switch, so by your explanation that would likely be the cause of the continual fan running.

vetteoz

iTrader: (13)

The pressure switch was fitted on a A/c hardline under the hood

https://www.thirdgen.org/forums/post...392-post7.html
https://www.thirdgen.org/forums/post...612-post8.html
https://www.thirdgen.org/forums/post...956-post5.html

Crusherfied

iTrader: (2)

Ok, so I put the car into storage for the winter not long after the last post. I just pulled it out the other day and am eager to get these problems figured out. Can someone please post a picture of this A/C hardline and switch that vetteoz is talking about? I deleted the A/C from the engine during the swap as the receiving car did not have A/C. But I likely still have the wiring sitting under the hood, so if I can identify the correct wire, maybe I can ground it properly so the fan doesn't run all the time, if that indeed is the issue.

I'm taking the car into a shop tomorrow to have it put on a scope to see if the ECM is acting up.

vetteoz

iTrader: (13)

https://www.thirdgen.org/forums/elec...tch-turns.html

https://www.thirdgen.org/forums/post...612-post8.html

https://www.thirdgen.org/forums/cool...re-switch.html

Crusherfied

iTrader: (2)

Thanks. But I've found the search engine on this forum leaves something to be desired.

So I just had a look under the hood near the front of the passenger side strut and found a two wire connector (Blue and black wires) that still had my label I had taped on that says "A/C" (I had done the engine swap two years ago so my memory is foggy). So I'm pretty sure these are the wires I'm looking for and I don't see any others just hanging around.

Question is now, what to do with them to ground them out? Do I simply ground one of them? If so, which one? Or do I ground both?

Thanks again folks.

Crusherfied

iTrader: (2)

Ok, so after doing some thread reading, sounds like the drivers side fan is the primary. This is the fan that is constantly running as soon as I start the car (the fan doesn't run with the engine not running and the key to "on" however). As mentioned earlier in this thread, this symptom points to an ECM issue.

With having the A/C switch wire disconnected, shouldn't it be the secondary fan that comes on? That one never turns on.

Regardless, I'm hoping the diagnostic tells me something.