EFI toMFI,Throttle linkage mystery

[C.K. Piquup]

I am changing to mechanical pump on my`95.From what I`ve read there seems to be some question as to how to hook-up throttle linkage.What is the problem,and what are the solutions?

[ucdavis]

1) APP module has an operating range that PCM reads & will set codes if not within range.
2) Cruise control is via PCM by controlling DS4 pump signals (which go away when converting to mech).
3)PCM has interaction w/auto tranny that may be affected when PCM perceives DTC codes for APP & DS4
Solutions were at least partially covered in earlier year articles available in hard copy reprints @ bottom of Join Us page here on TDP.
Good luck, & post your results as you proceed.

[C.K. Piquup]

My truck is a 5spd.I`m aware of the cruise problem/remedy.What`s the APP?My original question is about the problem/solution with pedal/linkage adaption.

[Bobbie Martin]

Welcome to the dark side! You have no worries with the APP. You can dump the APP (electronic throttle pedal) and install a cable type throttle pedal from a gas truck. It bolts right in. The APP problems are only with an automatic and the DB2 pump. That is, unless you are keeping the vacuum wastegate system. It uses the APP sensor. If you are going to use a Turbo Master, you will not need the APP. I would keep the PCM to control the glow plugs. The APP is not needed for the glow system. If you have any other questions, feel free to email me or post on the forum. I have done the DB2 conversion on our Suburban.

[C.K. Piquup]

Thanks Bobby,I should be good-to-go.My turbo is a non-wastegated GM8,so...I wondered if the gas throttle was the same as`92/`93 TDI.Actually I worded my question to get most info.It seemed to me alot of pondering was going on about this "missing link." Even at Peninsular they said I`d have to work something out there.I went to my Chevy dealer w/VIN# from my`92GMC and ordered the pieces listed for it.I could see mounting was the same,and it looks cut`n`dry to me.In fact,my`91Sub mounts the same.Except,the rod bends opposite.

[Bobbie Martin]

I don't know if the 91-92 TDI pedal is the exact same as the gas truck, but the gas one works fine. You can get them from most any salvage yard for $10-20. There is a plastic plug on the firewall where the cable goes through, it just pops out and the cable plugs right in. I unplugged the wires from the APP and tied them up away from the linkage. Really, to swap the entire pedal over is less than 10 minutes work. If you had factory cruise, email me - I have something you may want to try.

[C.K. Piquup]

I`d be interested in your"cruise-solution."I`ll e-mail you,probarly not until next week.We`re of to share turkey with the Kinfolk.Have a good one yourself.

[Jim P]

I thought that even a gm8 had a wastegate. Am I wrong about this?

[C.K. Piquup]

It`s a performance unit from Peninsular Marine.Original units are wastegated.

[Jim P]

Now I understand.

How much does one of these peformance turbos cost?

[C.K. Piquup]

I`m not sure what one would cost.Go to www.peninsulardiesel.com.As (http://www.peninsulardiesel.com.As) with many websites,information is limited and does not list nor price every product/option available from them.But,you can call,fax,or e-mail and they`ll help you out.It`s a candy store for sure.I just ordered the 300hpMFI engine for my`95.Been wanting to ever since I found out about them,but now I need one.Actually,since Jan`03.

[Kennedy]

Originally posted by C.K. Piquup:
It`s a performance unit from Peninsular Marine.Original units are wastegated. Then it is NOT a GM 8. It is likely a Shwitzer turbo...

[C.K. Piquup]

I didn`t ask,but thought I had read they were reworking GM8s.I haven`t recieved engine,yet.I know they refer to it as Medium-Duty.I stand corrected.

[C.K. Piquup]

Shwitzer it is.