4L80e install - Questions

[critter]

Bear with me. Life keeps getting in the way of my shop time. Sorry for the slow progress.

[aronhk_md]

Totally understand

[critter]

Have you ever had a project that pushed you to the edge of selling it all and buying a KIa?

You've all been privy to my struggles with the 4L80e transmission swap. I got so frustrated that I parked it in my garage and left it for a while. The crazy part was, when I did what I thought was right and quit listening to TCI (they sell the transmission control unit made by Powertrain Control Solutions) it seemed much better. That involved making major changes to the table that controlled the throttle position sensor VS line pressure. Of course my opinion was based on my putting it on the trailer and pulling it off the trailer and into the garage.

So I figured I'd take a break from flailing at the transmission and install the electronic gauges. What the heck, that would be fairly non-invasive and allow me to still keep moving forward, right? Wrong. I put it all together and the new electronic tach didn't budge. Oh, and the temperature gauge I wanted to retain didn't work either. I decided that I'd swap my known, good working oil pressure/temperature gauge into the modified cluster. That was no big deal The tach manufacturer was called regarding the non-functioning tach. After a few tests it was returned to them for repair.

I bought a Speedhut Revolution series speedometer and tachometer because they could be fitted to the stock dash bezel without modification. In that respect, they work as advertised. Today the repaired tach came back and I went to work. Sure enough, this time it powered up and I was able to set the shift point and the progressive lights leading to the shift point. It even allowed me to set the brightness level.

Then I fired up the car. At roughly 2000 RPM and up it was steady and showed the progressive shift lights as advertised. At idle it bounced like Tigger from Whinny The Pooh on a combined caffeine and sugar rush. Hey, no big deal, I'll cut that purple loop wire that they say to cut if you have excessive electronic noise and and erratic needle. So I did. Now it reads the idle just swell. Of course it won't read any RPM over about 2500 but, hey, you can't have everything, can you?

LOL.

Critter
(gotta laugh at this point)

[critter]

I drove it tonight.

I thought it might be slipping still but the pressure was right. The converter may just that loose. Once it stalls up it goes. The pressures are so high it's BANGING the 2-3 shift but when it does, it hunts between the 2-3 shift.

I data logged it so I'll review. I've got to do 2 things. First is soften up the line pressure. The other is lower the shift points. Jake, if you read this, should the converter be pretty soft or should it feel more like a street converter?

[critter]

I made some progress today.

After airing up the flat tire I realized that I should recalibrate the TCU after putting the new wheels and tires on. They are slightly shorter. While I was at it I installed that profile that TCI sent and I'd upped the line pressure by 10 percent. Then I recalibrated the TPS for good measure.

I took it for a drive and watched the pressure gauge. The pressures were more in the 120 psi range when driving now and the "shift" was firm but not harsh. I say "shift" because it would make the 1-2 shift as you'd expect. However, I never could get it to make the 2-3 shift unless I let off the gas. Then, it seemed that I needed to be above about 30mph for the 2-3 shift to kick in. I could then cruise in 3rd unless the speed dropped below that 30mph mark again.

I went into the shift point tables and tried dropping the upshift point on the table by 10 percent but it didn't seem to help any. I fiddled around with some other ideas but nothing seemed to help.

I think I'm on the verge of having this worked out if I can work through this upshift problem. I'm sure I'll need to do some minor tweaking after that but I'd sure like to get it all the way through the gears, up and and down one time!

[turbo kid]

Remember the 4l80e has 2 vss

[critter]

OK, I'm going to eat my words on TCI and their tech folks. They asked that I send them the harness and computer. Both have tested out fine. Now the tech, Russell Culver, is offering to drive it back to my house, help me re-install it and see if we can sort it out. That, my friends, is customer service.

I'd ad that I did find some slop in my TPS when I was pulling it all apart to send to TCI. I've replaced that TPS so hopefully that will help as well. Russ, like me, is puzzled by the odd datalog regarding the speed sensors. Might be we have bad sensors but more on that later.

Man, I'm learning a LOT about the 4L80e transmission. That's one good thing about all this.

[critter]

OOps!

Russ came over and we spent the morning tuning. He couldn't figure out why the thing needed so much throttle position to achieve a shift. Then he asked me about the carb. When I said Quadrajet the light went on. The small primaries require a lot of throttle position to achieve the same amount of "go" from the car. They don't tune much for Qjets. There you go.

I drove, he worked the computer and by the end of the morning he had it shifting pretty nicely. He had to pull the shift points WAY down because of the carb and torque of the motor. Then he said we needed to run it WOT a few times just to see what we had.

I still had the pressure gauge tapped into the transmission. On the second WOT it spun until 30mph (data logs are cool) and then hooked. It started hunting between gears so he had me get out of it. When I did, the pressure spiked and WOOSH! The pressure blew that hose off the fitting that went into the transmission. AT fluid hit the exhaust and we had quite a smoke show going.

The good news was that I was out of it when it let go and we just coasted down to the foot of the hill. I don't think I really hurt anything. I called AAA and had the roll back operator dump it back in the garage. I'll crawl under there, pull the remains of that fitting and plug it now that I know we're in pretty good shape on the tune. The I'll fill it back up with fluid and go again.

it's always something.


My snail trail:



The offending gauge:



I'll have a mess to clean up under the car:



Russell Culver from TCI was still tuning on it after the incident. Thanks Russ!:



At least I had time to make a photo of the car with the new wheels and tires while I waited:

[fishtail8]

Glad to hear you're finally getting somewhere with this deal. Almost ready to log some seat time, good on TCI for helping you out a ton.

[Kenova]

OOps!

Russ came over and we spent the morning tuning. He couldn't figure out why the thing needed so much throttle position to achieve a shift. Then he asked me about the carb. When I said Quadrajet the light went on. The small primaries require a lot of throttle position to achieve the same amount of "go" from the car. They don't tune much for Qjets. There you go.

Damn! was this the cause of all your problems?
It's always the simple things that seem to trip up a person.

Ken

[critter]

I'm guessing it was a large part of it. And me being a newbie to the interface, I wasn't sure how to adjust things. Russ did a fine job of working through it and will now take that knowledge back to their support group to help future users like me. I can't say enough about the fact that he came to me and helped work this out. That was outstanding customer support.

[BonzoHansen]

Wow, 3 cheers for Russ. You better have bought him a good dinner!

[critter]

I did manage to buy him a beer and some lunch. I wanted him to hang around for our cruise in and ZZ Top concert that night but he had to get back for a school he had to attend on Saturday on EFI. Trust me, I won't forget his help. Somewhere, I'll be able to take care of him.

[aronhk_md]

Hey Chris....glad to see its up and running correctly now. Have you had a chance to enjoy it at all? Can't wait to do the 4L80 conversion, but looks like winter now before I go there. Want to enjoy the car over the summer.

Aron

[critter]

No, not much yet. The spring monsoons have begun and I'm installing the Shrifter now. I was hoping to button that up this weekend. I might get it back on the road next week.

[aronhk_md]

I'm jealous.....I love the wheels. Dont want to trade them for an old set of 15" centerlines do ya?

LOL

[critter]

I ran out of time today so no test drive. I'm itching to go though.

My special thanks to Steve Chryssos who spent some time on the phone with me today helping the village idiot figure out the wiring. The computer show everything to be operating as expected. I'm pumped!

[NOT A TA]

Ah... The part I've been waiting for! The Paddle Shifters!!!! Glad top see ya got the trans issue straightened out. SEE ya shoulda took back the Demon and tried it LOL!!! Wheels look good!

[critter]

He's alive! Where have you been? We miss you on Thursday night chat.

Don't let that Demon get away. I might have to buy that back from you some day. For now, I've got the Quadrajet and linkage working but that Demon was still the sweetest carb I ever ran. (But I NEED FI)

[NOT A TA]

Been working in the machine shop nights. Gonna start porting the heads for the Malibu engine tonight. I've been watching this thread but had nothing to contribute. Carb's still in the box, if ya need it let me know!