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I have a 2005 GTO with a 4l80e and Jakes manual controller box (the car was originally a manual so it has no TCM and the ECM does not interface with the transmission at all)
I just recently got the car started for the first time after adding a new engine and the 4l80. When I shift out of Park to R, 4, 3, 2, or 1, the motor feels like it is drug to a stop almost immediately.
I know a typical auto trans car has a few tables in the tune to keep the car idling when shifting to Drive, but I don't really have this with the manual ECM. Does this matter? I haven't had a chance to really tune the idle that much so maybe as I richen it up some, the idle will get stronger and it won't die. But given how quickly it dies, and that it died even as I revved the engine while shifting, I'm not sure that will make a difference.
My 2nd idea is that maybe the TCC is locked up? I currently don't have the TCC wire from the Jakes manual control box wired to a anything as I'm not sure whether it needs ground or 12V to engage. Anyways, I wouldn't think it not being wired up would default to 'Locked'?
Any ideas?
Last edited by FSAE_Junkie; 01-29-2015 at 10:11 PM.
I just put the rear of the car in the air and the got it idling in Park. When I shifted to reverse, the rear wheels went from 0 to 20mph in 0.200 seconds according the log. The engine stumbled quite a bit from the load but quickly recovered.
As I applied the brake, the RPM's began to drop. I attempted to give it more throttle to keep the engine alive, but it just wasn't possible.
So, I'm pretty sure this confirms that the lockup clutch is engaged. It sounds like this means the TCC solenoid is bad or something is wrong with the converter.
For those having more experience with auto's, what is more likely?
The TCC requires ground to activate with my manual control box (should have been covered on the instruction sheet). Be sure you aren't inadvertently grounding the wire.
That said in reverse or first gear, there isn't an oil supply to the TCC solenoid.
You may have an issue similar to the one posted recently. It's an issue that pops up occasionally on 4L80Es. Replacing the TCC solenoid might be a good idea because it is cheap and easy, the next steps are more painful.
So the transmission is a fresh rebuild but the tq converter is used. So thinking maybe the converter was boned, I tried rolling it down the driveway in gear. It rolled easily, engine didn't spin. So i think this means the trans is at fault.
Jake would you mind elaborating on the statement you made regarding no fluid to the tcc circuit in 1st or reverse ? Since mine is locking in 1st and reverse, does that imply anything?
I've read that other thread and I still don't understand how a new pressure regulating valve fixed the situation.
We've seen this issue with 4L80E's and there are several factors that seem to contribute. It is oftentimes a flow issue.
A lockup torque converter on most GM products doesn't have any release spring or other method to force the clutch "off". The transmission TCC valving reverses fluid flow to lock/unlock the converter.
The lockup valve in the pump is a two way switch. One direction it feeds fluid to unlock the converter, the other way it feeds fluid to lock it.
If you for any reason have low flow to the converter, it will tend to want to lock.
Low flow can be caused by many things. We make some mods to the pump and other places in the trans that help prevent this issue. The Sonnax line-to-lube PR valve will increase this flow, but I suspected it wouldn't be enough to help. Evidently it was on the previous thread. There are other methods to accomplish the same thing.
When you are running higher line pressures, the flow is reduced unless you make changes to increase the flow.
There are several other factors that can also affect it. We've spent quite a bit of time testing different stuff on the dyno and have learned a few tricks.
Call me at the shop tomorrow and I'll give you some things to try before you condemn the converter. I don't mind helping but some of what we do is proprietary and some I will share but only with our customers.
Once in gear how would it run going down the road? Can u go to rpm limit? My jeep dies on idle. I feel a bit of on and off slipping in at low rpm and once it passes stall speed doesn't let the motor rev up too much. But in park and neutral it idles and revs like a dream.
Check out this link man he explains everything perfectly and will answer your questions even though its a swap, i think the tuning will apply to you alot.
Well, I hate nothing more than when you find a thread detailing a similar problem to yours, but the OP never comes back to explain what happened, so here goes.
I temporarily solved this issue by just buying a junkyard 4l80e and putting a Transgo HD2 kit in it. It was enough to let me drive the car for the first time in 3 years, but the trans had 200k miles on it, so I wasn't expecting much. It ran okay for the last 3 months, but it blew the front seal out last week. Hoping that was just because of age/miles and not because of the constantly high line pressure from running it manually. I'll just light the car on fire if I have to drop the trans and change front seals every 3 months, ha.
Anyways, so I had reason to go back and figure out what was wrong with the locked TCC 4l80e. As Jake implied, the pump was a likely place to start. Thought I'd start with the Boost Valve.
It took me about 30 minutes to get that valve/bushing out. I had to keep working it back and forth with a punch and hammer on one end and prying on it with a screwdriver through the pump passages/pounding on the other end. You can't see it all that well in the picture, but there are hundreds of scars down the side of it.
What's interesting is that the other OEM bushing (from the temporary trans that I replaced with the Transgo one) won't even go into the bore. So the pump housing is likely undersized? I assume if this valve was completely seized in some given position, that that could explain why the TCC was permanently on?
Anyways since this was a supposed "fresh rebuild with a Transgo kit" that clearly has a jacked pump and no Transgo kit, I now wonder about the quality of the rest of the rebuild...
08-23-2014, 07:53 PM
4l80e - Car dies when put into gear 
