AintQik

iTrader: (3)

Lol Joe, I forgot how to save them both in HP and on the Solis. But I reviewed the logs and when it slipped or unlocked there was no command in the computer or anything else that changed. I have not looked at line pressure.

Only other changes were what you would expect to see with an increase in rpm, map o2 etc.

Trans is about out, I've been with my kids a lots today. The only converter I have for an LS car came from a 110k mile Z28 that I never drove. So I have no idea if that one works either. I am a manual guy, so I don't know if its common for a FCC to go bad or not. I can tell you the fluid in that converter is pretty burnt. I half tempted to just replace everything but for the sake of trying to know what failed I guess I will go through the pain of installing this converter and seeing what happens.

If it is the clutch and its slipping more rpm than an unlocked converter that explains why turning the tdc sol off drop rpm. It also explains why tapping the brake or increasing throttle both drop rpm. However I would have seen a 1000 rpm slip on the Tech. I was driving and the owner of the tech didn't mention it so I assumed it was ok. I don't know if I can see that in HP and with the Solis I was concentrating on the computer status. However, I will say that I don't think a converter works that way. But, we will see.

mrvedit

I fully understand that you don't just want to fix it (with a new trans and converter), but want to know what the problem is. Good luck trying out the other converter.

joecar

Yes, I think all of us reading along are curious as to what is the cause.

AintQik

iTrader: (3)

Well, just got done with the acrobatics that is replacing a TC on a 4th gen. I drove it for 30 mins and it was perfect. About to turn for home and I said aw, let me give it hell some more. Another 10 mins and it started doing to same thing. You cruise along at 55mph-2k rpm then it just flares to 2800 rpm and stays there. Give it throttle and it drops rpm. Tap the brake and it drops rpm. Takes heat in the tranny, about 40 minutes worth. I still can't see it being the computer. Computer don't care how hot the tranny fluid is.

I guess my next step is to try a tranny and new converter.

On a side note, after i put the stock converter in and got it to fail, I noticed it was surging at idle. I did a quick check and everything is hooked back up. I wonder if it is converter related. Is that possible? It sort of bounces up and down 3 or 400 rpm.

Sometimes i wish I couldn't fix things. I would be like 80% of the rest of the world and drop my troubles off at the local mechanic.

mrvedit

Wow, the mystery continues. Perhaps that model "666" PCM is the problem.

Any chance you can log the transmission reported temperature?
If the temperature sender (part of the pressure switch) reads way to high, the PCM may enter various engine and trans "limp" modes.

FTICONVERTERS

iTrader: (3)

Aint, well doesn't seem the converter is the issue but while you have it out I can lock up test it for you and look at it. I don't believe that the converter is the issue but certainly don't mind looking.

Greg

AintQik

iTrader: (3)

Nope Greg I can't see 2converters doing almost identicle failures. I'm going to have to take advantage of one of these holiday 4l60 sales. I'd like to take you up on that offer. While its down there I will gladly pay to have it gone through. Turns out its a SB2800, but that will probably be ok for what I do. I will give you a call after the holiday and get this thing down to ya and go from there.

So, I have been going nuts all day thinking about this. What in a tranny with a new valve body would cause the tcc to slip when hot? Wouldn't I see other issues if it were the pump? The stock converter started to bounce in and out of lock today cruising. Not just come out. It went in and out if I held a steady throttle.

AintQik

iTrader: (3)

The indicated temp on the scanner was 136 degrees when it failed.

I would buy a computer but they are pricey and I seriously doubt it is the problem but at this point i have no idea. In HP for tcc sol on and off is it just monitoring ground? Just can't see it losing ground or 12v aftwr 15 minutes. could it actually be 4th slipping? But why would rpm go down when i command tcc sol off? The fluid was dark when I started. Smelled a little burnt. Still no codes. Occasionally I will get a 1870 but it hasn't come on since the vb swap.

mrvedit

My trans temp idea was just grasping for straws.

If you are electrically comfortable, you might put a volt meter on the line going to the TCC Solenoid - I think that is Pin 32-BLUE on a '98 PCM. The PCM draws this to ground to activate it - in other words +12V is solenoid off and Ground is solenoid on.

FTICONVERTERS

iTrader: (3)

????? what about stator bushings. If they are worn they will leak converter lock up oil. The rear one is the culprit most of the time if this is the case. This should however make the converter lock up backwards but make it slip when locked up.

Greg

joecar

Maybe the case and/or VB is warped and cross-leaks at the separator plate when temp is sufficient...???

AintQik

iTrader: (3)

Output was good out of the computer and lines were good. I yanked and twisted the heck out of them and they never blinked. If its not internal to the trans I dunno what the hell it is and I will probably never know why unlocking the converter drops rpm.

New trans will be here soon and FTI already has my new converter in the mail. I guess we will see. I hate throwing parts at problems but I'm out of troubleshooting. I have no idea how to monitor trans line pressures or whatever else can be wrong. If this don't work it's going off a cliff. Well, I will try a computer then drive it off a cliff. Lol

I looked at the plate Joe and so no evidence of a cross leak. But could be.

AintQik

iTrader: (3)

So long story short is I have lockup.

Not so short version. I replaced the trans and saw a nick in the input shaft oring. I don't think it was causing issue but who knows.

New trans vibrated like hell, took the new poly mount out and most of the vibes went away but no lockup. Screwed around with it and saw it was locking up when commanded but it wasnt shifting into 4th. Course it was not locking in 3rd, I told it not to. Then I realized it was kind of a dog and no **** it wasn't going into 1st either. Could a brand new trans have a bad solenoid A? Dropped pan and it ohmed out fine. Took it out and made a harness for giggles and grins and low and behold it was not energizing. Swapped out the solenoid and whall-la it works like a champ. With my luck I got a bad trans. Figures. Now I'm worried about the rest of it. But at least we will see. I have not got it super hot, remember it kind of worked when cold before, but the difference is so great I'm pretty confident I got it fixed. I saw 1800 rpm at 55 mph. The verter was solid, thanks FTI, Cars has a bit more snot with 1st gear lol. So, on to the next issue.

joecar

Sol A was bad... thanks for the follow up post.

AintQik

iTrader: (3)

On the new trans Joe.

The original problem is still up for debate. 4th was slipping with lots of clutch material in the fluid and there was a nick in the input shaft o ring. But who knows.

New trans fixed it.

joecar

I hate it when new parts are bad.

mrvedit

Yeah, it was a bit confusing; AintQik's replacement trans was bad too, but in a different way. Fortunately AintQik now has enough 4L60e knowledge and experience to to quickly diagnose and fix "normal" problems.