Partial Mechanical IP conversion?

[AndyL]

If I were to rig a way to keep the electronic throttle contol to the ECM and actuate the cabled operated mechanical IP would my auto tranny still shift correctly?

Assuming I left all other sensors in place except the ones on the Electronic IP.

[Peter J. Bierman]

Yes it would, but you can take the TPS signal from a pump mounted sensor and skip the electronic pedal and mount a oldfashioned one.
The product review on the stand alone computer uses this sensor.

Peter

[AndyL]

Those aftermarket controllers are about $1000, I could save this if I could get the stock ECM to shift the tranny with the mechanical IP.

Crafting a dual purpose throttle cable shouldn't be too hard.

[ALSAIL]

How would you install/restore cruise control after the conversion to the mechcanical IP?

[Peter J. Bierman]

What I getting at is not using the after market controller, just converting to the TPS sensor that is pump mounted, makes the conversion easier.

Peter

[DA BIG ONE]

Originally posted by Peter J. Bierman:
What I getting at is not using the after market controller, just converting to the TPS sensor that is pump mounted, makes the conversion easier.

Peter Common sense says you are right on this one, but, I wonder if there are other issues we maybe missing here like with the wiring between the 2 TPS units, or?

In my case, the t-case NP246 has 3 speed sensors for the autotrak "which I can do without" just keep the 4wd hi, 4wd low, then there is the tranny 4L80E issue.

I will be getting the factory books for my truck before I start this conversion.

[Peter J. Bierman]

Yes, there are different connectors but the signal is the same.
This sensor was used on non EFI trucks with the 4L80E transmission.
Humvee's use them too.
The pump mounted sensor has a 3 pin connector
the pedal version a lot more.
Find the right 3 wires is the key.
I am not sure what the computer thinks of this and it might give error codes.
MP did this and should be able to fill you in on this.
There are articles about this in the DP reprints.

Peter

[More Power]

Andy,

A modified APP module assembly has been tried, and tried and tried..... I know of a couple that are reported to work satisfactorily, but it is not an easy solution.

One of the biggest problems is that the mechanical DB2 fuel injection pump is weighted to produce more power for the first 50% of the pedal movement, while the DS4 electronic pump is weighted to the final 50%. What this means is that the trans doesn't downshift when it should, and shifts are too soft. Or to say it another way, the trans responds as though you're barely on the pedal, even when you're really into the power.

A combination accelerator pedal can be made to work, and we've produced articles on it. But, I'd recommend going the standalone TCM route for best driveability.

MP

[DA BIG ONE]

Originally posted by More Power:
Andy,

But, I'd recommend going the standalone TCM route for best driveability.

MP Going to get the TCM next week.

Still trying to figure out how to use the NP246 with the conversion.

[More Power]

Pull your ECM fuse(s), then see if the Txfer case will still shift correctly. I suspect it might shift without the ECM.

MP

[AndyL]

Originally posted by More Power:
One of the biggest problems is that the mechanical DB2 fuel injection pump is weighted to produce more power for the first 50% of the pedal movement, while the DS4 electronic pump is weighted to the final 50%. Is the 99 ECM slightly different? In a recent conversation with Bill Heath he mentioned changing the first 30% heavier front end to a more linear range on his 2.0 reflash.

[mklein]

I recently changed my 95 3/4 ton suburban from a tbi 454 to a mechanical 6.5. One of the issues was transmission control. I used a Delphi T42 TCM for a late model HMMWV (or you could use one for a 6.2 with a 4L80E). The only issue is getting the TCM engine RPM, but if you have a side mount for no turbo, you can use the drive that mounts on top of the oil pump drive. I can dig up some part numbers if you like.

[vernj4]

mklein...we would be most grateful for your input/part numbers for this project. Thanks in advance!

[mklein]

Well, the TCM is actually a T32, I typed in the worng number. The T42 is a CAN based controller that we are using to replace the T32. Anyhow, the service number for the T32 that I am using is 16196390, and the EProm for it is 16229207. Since I have not recieved the Eprom yet, its being shipped out of Chicago. I can't say for sure if it works until I actually try it, but I don't see any reason why it wouldnt. The Eprom number is for a 1996 model, and there have been subsequent part/number changes for all of the following years. Going to try and see what changed each year to see if one is better than another.