team39763

iTrader: (3)

My buddy and I swapped a 4L80E into a 99 Silverado(NBS). We got the pins in the right slots(22 and 23) and bought Nelson's adapter kit. But the truck won't run correctly. Before the speed sensor wires were hooked to the ECM, it ran like it should, it just wouldn't shift correctly. After connected pin 22/23, it won't take WOT. It kinda just makes a lot of noise or just bogs down like the pedal isn't being pressed. We are sure the truck had plenty of gas, fluids were fresh and topped off. No vacuum leaks.
Here's what it does. He takes off from a stop - full throttle, won't break the tires loose(No TM) and barely moves the truck. Max speed with pedal floored was around 60 or so and took a long time to get there. The trucks would sound very rough and out of tune. But when he uses part throttle, the truck hauls *** like it should and the trans will shift like it should and the truck sounds smoother aswell. Another thing we noticed is that it's moving in neutral and reverse doesn't seem to work...as if it's locked or fighting a forward gear....the truck will rock backwards then jump forward.
I realize the Neutral and reverse problems could be linkage related, but that doesn't explain why WOT doesn't work. I'd appreciate any ideas or advice.

performabuilt

iTrader: (25)

You have and internal trans issue causing the movment forward and the locking reverse I am afraid

team39763

iTrader: (3)

MAN! that sucks...I hope that's not the case.

performabuilt

iTrader: (25)

I do hope I am wrong but I would bet I am right, Sounds like the forward clutch is fused

eviltwin_1987

iTrader: (18)

did you double check the tune.

tptransmission

Remove the wires that you put in for the speed to see if the engine runs. I on't think I would try anything wideopen until the transmission is working better. Unplug the transmission and gently try to drive it. Should start in 2nd. Verify your linkage adjustment.

team39763

iTrader: (3)

The ECM was tuned for the 80E. I'll ask him to unhook the wires and see what it does.

red83

iTrader: (64)

is your turbine speed hooked up?

i HAD to hook both sensors up on mine because mine was doing the wot bog just like yours is now. almost like its in transmission protect mode or something. driving it for over 1000 miles flawlessly so far.


edit: and my car started idling different after i hooked it all up correctly

red83

iTrader: (64)

i think it is pin 21-22 or 19-20......................or close to it.

30th t/a

iTrader: (51)

I think im in the same boat as you guys with my 4L80e. My car drives fine on the street but when tried doing a full throttle tune in 3rd gear, my tuner would hit the throttle at 3000 and it would get to around 4200 and just fall on its face allowing the motor to hit the rev limiter....or atleast that what it sounded like. 2nd gear worked fine on the dyno so he tuned my car in 2nd gear.

Also, I cant not power jack my car so I know something is screwed up.

Im wondering if I got my wiring wrong???

red83

iTrader: (64)

post up what pins you have vss going to, and the turbine speed pin locations also

30th t/a

iTrader: (51)

I have a wiring harness I got from Speartech. 2 wires which are Red & blue. I have them going to pin 22 and 23. Each wire has a tag on it with the pin number it needs to go to.
Is this the VSS your talking about??

Im not sure on the turbine speed pin wires or location.

I am using a OEM A4 harness and the Speartech harness. The A4 harness just bolted to the PCM and then I routed the Speartech harness to the pins # on the tages.

I really appreciate any help you can give me.
This problem has been driving me crazy.
thanks!

red83

iTrader: (64)

im not at home right now, but i think this is how mine is

20 and 21 is the vss

22 and 23 is the turbine speed for the 4l80e (front plug on the transmission) you will have to look at a 3/4 to 1-ton truck pinout to find these listed


look at this pinout chart. not sure what year yours is, but all 99-02 are the same.

http://www.ls2.com/boggs/torques/2001pinpcm.htm

30th t/a

iTrader: (51)

So your thinking the pin numbers on my Speartech harness could be wrong, or maybe not correct for my year transmisson?

I was told my 4l80e came out of a '94 Van.

red83

iTrader: (64)

the wiring is all the same in the transmissions. the pin #'s you mentioned do not match the pinouts for the vss.

pin 22 and 23 are for the turbine speed/iss(input speed sensor) (converter speed) in the 4l80e.

you have to have the rear sensor (vss sensor) pinned in the the pin locations # 20-21

red83

iTrader: (64)

i have both sensors plugged up in mine.

just make sure you have the correct one plugged in to the right sensor.

30th t/a

iTrader: (51)

I just checked it. I got the Speartech harness going to the Front sensor and to #22 & #23 pins on the PCM. The rear sensor wires are green & purple and they are in the stock A4 harness. I didnt check to see which pins they are in but they are stock so where ever the stock wires go on the PCM is where they are going to.

I guess I have the sensors hooked up corectly. Could I have a bad sensor? I bought the transmisson and had it completly rebuilt but it still has the original sensors.

red83

iTrader: (64)

can you post up your tune?

30th t/a

iTrader: (51)

No I cant. I had Bryan from PCMforless dynotune the car.

Being that he was able to do a WOT dyno tune totally fine in 2nd gear does this mean that the sensors are working properly?

I wonder if maybe the #22 & #23 pins that I installed in the PCM could be damaged? I remember they were a pain getting them seated in place.

red83

iTrader: (64)

that is very possible. take the connectors off and check the pins in the computer. also be real sure the connectors are seated all the way. i have had trouble with them pushing out before when you plug them in.