Razor

I had this trans in my car previously with my initial LS swap and it was working good. It had over 200K miles on it so, while doing other upgrades, I decided to have it rebuilt. I went with a local guy who does these transmissions constantly with no negative reviews that I know of. Complete rebuild with HD2 installed.

Re-installed trans with new Yank converter, new 30K cooler, and MLPS switch. Took car out for a short drive and it feels like the car is starting out in 3rd gear? Also, the cooler seemed to be putting off a lot of heat.

Drove car for about 1/2 mile total and parked it. I've searched a bit and see this is not all too uncommon of an issue.

I think it may be an electrical/wiring issue but need to know where to start.

Will unplugging the MLPS do anything? This is the new part that I added into the equation.

Where else should I look?
__________________

Jake's Performance

iTrader: (2)

You need to plug a scanner in and look at what is being commanded.

It's an electronically controlled transmission, so other than the basics of fluid level, shifter adjustment, and fluid pressure checks, you need to start your diagnosis by checking the control system.

Razor

Transmission does not shift either...stays in 3rd gear the entire time.

When I manually shift it into low gear, it feels like it is fighting itself and gets hot quick! Had to pull over and let it cool then back into drive.

mrvedit

Are you sure it is 3rd gear?
Limp mode on a 4L80E is 2nd gear. (Limp mode on a 4L60E is 3rd gear).
The excessive heat indicates something is slipping; the lockup clutch in the converter is a possibility.
Have you tried disconnecting the trans connector?
This should give you only 2nd gear, high line pressure and no converter lockup.

Razor

No, I need to try that.

I'll give that a shot tomorrow. I did pull the connector a bit ago and found that I do not have power to pin E.

See what I come up with later and will report back with my findings. Also, borrowing a scanner to see if it shows any codes.

Razor

Unplugged trans and no change.

Pulled it back into the garage and left it. Frustration got the best of me.

Jake's Performance

iTrader: (2)

If you don't have power on pin E, unplugging the connector isn't going to change anything.

Razor

I did not check for voltage specifically but assume it is good based on continuity check I did today. Should I see 12V with key in on position at pin E or?

Another issue, the transmission connector does not snap into place. It pushes onto the transmission but does not make a positive lock. This is with the arrow located on the top of the plug while installing it. I have tried squeezing it 3/9 and 12/6 positions with no effect.

Razor

Confirmed I have 12V at pin E.

Also, I was able to push connector on a hair further.

No change in transmission operation.

Going to look for a how to on the shift solenoid test.

Razor

Found problem.

Plug in valve body was not installed all the way causing a cross leak.

Seated plug correctly, new gasket and fluid and it is good to go.

mrvedit

Glad to hear you found and fixed the problem.
And thank you for updating the post.

For those of use less familiar with the 4L80E, what plug are you referring to? Part of the HD2 shift kit?

Razor

Circled in RED

The plug was installed with the roll pin through the plug initially. This caused my problem. Clearly states not to install plug that way but the builder saw otherwise I guess... Works good now.