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1990 Burb. 4L80/np241?

Confedneck

Confedneck

3/4 ton status
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I have a line on a 4L80 from a 1994 k2500 6.5 truck. I understand this truck to have a separate controller for the trans. I have done a little searching here, and can't find exactly what I need, and not wanting to miss out on this, I ask for your input.

Will my 241 from my 1990 burb bolt up? Do I need a different adapter? What else do I need to make that trans work in my truck? I don't really want a manual valvebody. Can I feed the TPS signal from my factory TPS to the controller for the trans?
 
The '94 K2500 should have a NV241 on it already. Front output on the wrong side but it should be a NV241. Only the 1 tons got the bigger BW case.

Pretty sure all the internals are the same and it should bolt on.
 
Regarding the controller: You could update your Sub to the 16147060 controller (PCM) that will controll your EFI as well as the 4L80e.
 
Your 241 will bolt directly to the adapter on the back of the 4L80E.

Your current 241 will have a 27 spline input while the 4L80E has a 32 spline input gear. You need to swap input gears in the 241, we can get that for you.
 
Keitha said:
Regarding the controller: You could update your Sub to the 16147060 controller (PCM) that will controll your EFI as well as the 4L80e.
Click to expand...

Yes it will. I think you have to get a harness from a 91+ to use it because your current harness shouldn't have the pigtail for the tranny.
 
1991 was the only year in the R/V series to have the 4L80E option in 3/4 and up chassis. I have a harness some where from a 91 R2500 burb i found in the boneyard. It takes a different ecm...and controls the Tbody injection as well. Ya might scrounge said ecm and a 91 and 90 factory helm wiring diagram manual and mod ur harness to do what u want.
 
Confedneck said:
or i can buy the tcase too, and snag the input?
Click to expand...

I'll have to check some literature back at the office on Monday but they changed the gears at some point in that general range, I'm leaning towards the 94 being the same as the 90 but I don't remember for sure.

You have to use an early input with an early planetary set and the same for the later stuff. Doesn't seem that one is better than the other, simply a change.
 
Confedneck said:
half ton.

Keith, that controller will control my TBI and the 4l80?
Click to expand...


Yes. The PCM is a more advanced design than the ECM's up to this point. It does incorporate the electronicly controlled transmission as well as all the TBI.
You should be able to find a wire harness for it. Make sure you get both the tranny and engine harnes'.
 
i'm thinking about the same swap, from what ive heard the 91 4l80e trucks had a stand alone trans controller. i'll try to track one of those down.
 
muddysub said:
i'm thinking about the same swap, from what ive heard the 91 4l80e trucks had a stand alone trans controller. i'll try to track one of those down.
Click to expand...


This is incorrect. They do not have a stand-alone controller. The trans controller is integrated into the PCM that also controlls the TBI. The specific PCM is the 16147060. You can use it as a stand alone tranny controller, but you would still need to connect all the sensors etc to the motor, so you might as well just use it for both, the motor and tranny. It is a better controller than the previous versions.
 
Keitha said:
This is incorrect. They do not have a stand-alone controller. The trans controller is integrated into the PCM that also controlls the TBI. The specific PCM is the 16147060. You can use it as a stand alone tranny controller, but you would still need to connect all the sensors etc to the motor, so you might as well just use it for both, the motor and tranny. It is a better controller than the previous versions.
Click to expand...
What if I converted to carb. Can I just use the computer to control the transmission. I have a 90 k5 blazer and we put a 454 and it killed 3 700r transmission already. So o have a 91 4l80 out of a suburban I want to install but don't wanna spend almost $1000 for a controller
 
...and this thread shall Rise From the Dead!

I'm not sure it is so simple. The trans will need a lot of the sensors used on the motor to work, ie: throttle position sensor, mass air flow & rpm to calculate load etc. There is probably a way, but you will have to research it.
 
I looked at this same swap when I had my ‘85. A stand alone controller is about the only way to go and its rediculous they are so expensive. Modifying a TBI setup from a ‘91 is going to be a test of patience and electrical gremlin chasing.
 
Sliccricc310 said:
What if I converted to carb. Can I just use the computer to control the transmission. I have a 90 k5 blazer and we put a 454 and it killed 3 700r transmission already. So o have a 91 4l80 out of a suburban I want to install but don't wanna spend almost $1000 for a controller
Click to expand...

Really need to dig into what PCM's were offered up to 1995.

I find it hard to believe that it's really that complex to retrofit a TBI/4L80E PCM into a pre-4L80E rig. AFAIK essentially all the TBI stuff was the same until 1995 (I think there was some injector oddity, and big block vs small block) but I would imagine at this stage, that has all been worked out.

Yes, probably takes some modifying of the PCM programming to work, maybe repinning some terminals, but those being newer units, may have a bit more support than the older ones.

I could be completely wrong, and it's far harder than I think. But given the 4L80E was used with TBI, and TBI had minimal changes from 1987-1995 on trucks, mixing the two just doesn't seem like it would be that hard.

Going forward with a computer controlled transmission, and going backwards from injection seems counterproductive.
 
I don't think it would be that hard IF you have an OEM harness, just got to figure out which inputs from the TBI side of the equation are used for the transmission. The hard part is that I think the GM PCM uses the sensors that I mentioned above that drive the TBI to also control the Trans.
 
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