4l80e

[Plymouth69]

I have a 94 gmc 3500 6.5 I changed I/P to a DB2 and did not have to touch the transmission it shifts fine I bought a manual valve body but did not have to use it why it has a Heath diesel chip in the computer would that have anything to do with it

 

[Will L.]

1. Welcome
2. WOW THATS AWESOME!
I would guess it has to be the ecm controlling it still, and getting info from the sensors like cps and temp. Way beyond my thought process right now of how.

If you can- show pics and tell what you did with electrical system so others might have same results without having to spend big bucks on a controller.

my 95 hummer is db2, and uses tcm which is same unit as your ecm except it doesn’t handle ds4 controls. But I have a 2 wire sensor, called ESS Engine Speed Sensor that is driven off oil pump, and the TPS throttle Position Sensor that feed info to the tcm for transmission to know what’s happening.
Somehow your ecm has to be getting the same input.

 

[Plymouth69]

All I did was change the pump and fuel lines plugged everything back up I could and it works I wish I new how

 

[Will L.]

So just left the harness all there and nothing plugged it where ds4 used to?

 

[Plymouth69]

Yep I plugged everything crank trigger wires on plenum everything but old DS4 wires and it works

 

[Plymouth69]

I already had manual wast gate and no vacuum pump it has a chip from Heath Diesel that made it shift hard already

 

[Plymouth69]

By the way this the best change I ever made I have owned this truck for over 20 years have had many different pumps and pmd with different fuel chips and nothing has run as good as this DB2 4911 I bought a 93 for the pump and fuel lines and the motor in that truck sticker on valve cover says 220 hp my 94 was 180 hp I have lots of parts if any body needs some several wiring horniness for pmd heat sink fuel lines ds4 pump whole four wheel drive truck less I/P and fuel lines live in Liverpool tx will not mail don’t care if sell or not

 

[THEFERMANATOR]

Without hooking up a TPS to it there is no way it is shifting correctly. It's probably shifting hard because it's in limp mode and running max line pressure and doing limp based shifts. If it's in limp mode I would not drive it. Early 4l80e's are bad about breaking hard parts from high line pressure.

 

[Plymouth69]

No it’s not much different than it was first to second I s a little harder not much everything works even lock up converter works good

 

[Plymouth69]

Is there anyway the transmission can get a signal from the tack or crank sensor

 

[Will L.]

Probably a smart idea to get a gauge on that trans.

 

[Plymouth69]

I have put over a thousand miles on the truck since I put the manual pump on and it has never run better so I am going to leave it alone I just thought someone might know why it works but I guess not

 

[Plymouth69]

I read somewhere that the speedometer and odometer guit working the truck wouldn’t shift gears mine works so maybe it is shifting off speedometer

 

[THEFERMANATOR]

I have put over a thousand miles on the truck since I put the manual pump on and it has never run better so I am going to leave it alone I just thought someone might know why it works but I guess not

I told you a few posts up how it's still shifting. It's in limp mode.

I read somewhere that the speedometer and odometer guit working the truck wouldn’t shift gears mine works so maybe it is shifting off speedometer

Speed input is but 1 part of the shifting equation. Basic trans controls like those found on 6.5's use output shaft rpm's, engine rpm's, and throttle input for warm engine shifts. There are multipliers and limiters that figure in, but engine speed, road speed, and throttle input are the 3 primary factors. If you take 1 away it can still shift in limp mode which will run max line pressure and less than optimal shift points. Running for extended periods of time in limp mode is a great way to tear up hard parts inside your trans. It's your truck, do with it as you please, but don't be surprised when you split the reverse apply piston and trash your pump from running high line pressure. When a trans lets go from high line pressure, it is normally cheaper to drop 3-4 grand on a new trans than fix the old one.

 

[Plymouth69]

I told you a few posts up how it's still shifting. It's in limp mode.


Speed input is but 1 part of the shifting equation. Basic trans controls like those found on 6.5's use output shaft rpm's, engine rpm's, and throttle input for warm engine shifts. There are multipliers and limiters that figure in, but engine speed, road speed, and throttle input are the 3 primary factors. If you take 1 away it can still shift in limp mode which will run max line pressure and less than optimal shift points. Running for extended periods of time in limp mode is a great way to tear up hard parts inside your trans. It's your truck, do with it as you please, but don't be surprised when you split the reverse apply piston and trash your pump from running high line pressure. When a trans lets go from high line pressure, it is normally cheaper to drop 3-4 grand on a new trans than fix the old one.

 

[Plymouth69]

I had bought a manual valve body before I changed the I/P I have done this before and never had one that would work I have had three 6.5 trucks and had this one since 2000 I can change the valve body just hate to since it works but guess I will

 

[KenDDiesel]

Do you have overdrive and lock up? When I bought my 91 v3500( 6.2 diesel mechanical ip with 4l80E) the tps was out, it would wind out alittle higher than normal and shift hard threw 1st,2nd,3rd. But had no overdrive or lock up..
Adding a tps to your db2 isn't a big deal. Purchase one for a 91 v3500. Or a 91-93 c/k3500 series..
Also would love to see pics of that 220hp valve cover sticker.
Had heard rumors of higher up rated 4911 pump trucks but never any real proof.
The sticker should show hp rating and the pump volume in mm3... would like to see that sticker.

Thanks Ken.

I had bought a manual valve body before I changed the I/P I have done this before and never had one that would work I have had three 6.5 trucks and had this one since 2000 I can change the valve body just hate to since it works but guess I will

 

[Plymouth69]

Yep I have OD and lock up converter works great I will take picture tomorrow if can figure out how to send it I have the whole truck if you need parts it really don’t need much pump and fuel lines

 

[Plymouth69]

My mistake 200 hp let know if you got it

 

[Plymouth69]

If you didn’t get pic I can try again