GM 6.5 Turbo harness

[borneo]

I am a newbie and this is my first experience with GM 6.5 Turbo diesel engine. I really need some helps here seriously. I have just bought a complete engine (or should I say incomplete) with 4L80e transmission and the T case. This engine was pulled from a 1997 Hummer H1 as the previous owner repowered his rig. Unfortunately after I opened the crate, the engine came with incomplete wiring harness in order to make it workable. Mechanically it looks good and it has only 65K mile on the engine. I need to furnish the missing PCM, engine harness, transmission harness, control harness (I think this is the harness that plug into the PCM). I did try to call the hummer parts store and the quote (>$5k!!!) for the engine harness, control harness, transmission harness completely freaked me out as it is more than what I paid for the GM 6.5 engine itself. I would like to ask for advice from expert here if anyone can share their experience as where to get a those Harness+PCM enable me to configure the engine as a stand alone unit. Any part number will help me too. I am really in big stress as I am stuck unless if I am willing to spend big bucks by getting those parts from Hummer dealer. Reply and helps will be highly appreciated.

[gmctd]

Welcome to the 'Page, borneo............

Go to Helm Inc for the factory GM '97 6.5 manualset, then hit the boneyards for a '97 PCM and harness - should be closer to 400bucks, all together

[borneo]

Thank you for your help gmctd. The Helm shop manual may help to identify parts but not part number. Overall it can be useful. It does helps when roaming bone yard. Unfortunately I am living overseas and visiting US once a year. I know there are a lot of stand alone engine harness for the FI gasser engine in the market but none of them make one for the GM 6.5 turbo diesel engine. But even if I can get one from the boneyard, it will still be an integrated harness that the engine harness is interconnectected to the body harness/control harness, this is just like ripping the whole truck harness. And also the PCM needs to be reflashed to get rid of the GM VATS (?). It is certainly technically possible but it could probably beyond my electronic knowledge. I have seen a lot of internet seller selling ther GM 6.5 turbo engine and PCM but there is almost none that supply a stand alone engine management wiring harness that one can buy and hook up to run the GM 6.5engine? Could I be wrong or bone yard is the only solution?

Unfortunately, the 6.5 project book I purchased from this forum doesn't have any information or even talked about engine harness (where and how).

Will aftermarket manual book like chilton/haynes help to construct one?

Thank you for advise.

borneo

[gmctd]

Another easier method is to convert the system to the '92-'93 mechanical DB2-4911 IP - requires the IP, throttle cable, one wire to the Fuel Shutoff solenoid, one wire to the alternator, one wire to the starter, one wire to the lift pump, one wire to the glow-controller, one wire to the AC compressor clutch, if equipped - plus power and ground, of course.

If it's a turbo, a spring can be used control the wastegate, just like on the '92-'93 6.5TD models

Then the '91-'93 trucks used a stand-alone Transmission Control Module for the 4L80E - TCM and required harness is avalilable aftermarket, or can be found in boneyards.

That conversion will be a fully standalone system

Member bobbiemartin published a how-to book to do just that, advertised on E-bay

[borneo]

Thank you so much gmctd, I have though of going mechanical at one time but I am afraid that I would look weird in the forum if I ever mentioned it. Now I know that it is not something unusual and as a matter of fact, until such a time I will have a chance to roam the boneyard this is at least an economical solution.

I hope you would be willing to educate me more on these:

1. What do I lose performance wise if I go mechanical (as compared to PCM engine)
2. What is the price of a good rebuilt mechanical Injection pump?
3. Without all those computer controlled sensor, will the engine still safe to operate even it is turbocharged?

Thank you, I do appreciate your advise!

Bornoe

[gmctd]

You would lose all the headaches of the PCM-based system, gaining the advantage of an easy to manage and maintain mechanical system designed to handle varying fuel quality - a little fuel additive, a little 2-stroke motor oil, change the fuel filter as required, and yer good to go.

The IP fuel rate can be turned up or down, an adjustable spring on the mechanical wastegate to set Boost limits - many '92-'93 6.5TD's were sold with that system - the change to a PCM system was for tighter control of Diesel emissions.

Do a search for PMD-FSD, low power-black smoke, erratic throtle, DTC 17,18,35,36,54, etc - won't see that stuff with the DB2 system.

Check with some of the DP vendors for IP pricing and availability, or do a search on the 'net for rebuilt Stanadyne IP replacements

[borneo]

gmctd, you bring light into my garage!:) :) :)
I have been in the dark and despair for weeks :confused: :confused: .
I will start searching for DB2, get a TCM and wiring, organize simple cable for lift pump, engine kill solenoid and starter wiring. I think I would need an EGT gauge when setting the mechanical wastegate. I have just ordered the GM 6.5 project II book from the forum as it talks about mechanical IP conversion too.

I am back to work, thank you again, what a relieve..:) :) :)

borneo

[gmctd]

Glad to help, dude - now you know where we are, keep searching, reading, and posting - you'll probably have better results on the 6.2 forum - with exception of the turbo, the mechanical systems are the same - the 6.5 Project Book should be a great help - that's one of the few I don't have, but as a long-time member, I was able to follow progress as it happened.

Best of luck on your project

[borneo]

After searching the internet, I am targeting of getting a PCS (Powertrain Control Solution) TCU to control my 4L80E. What do you personally think about their TCU? I think it is priced right ($700) wiring harness included. Of course this is, if I compare the Hummer dealer wants me to pay their H1 4L80E wiring harness for $2,500 a pop and another $500 for the OEM hummer TCM and probably won't even work. Do you have any recommendation of other brand of TCM that have good value for the money for 4L80E?

Thank you!

Borneo

[borneo]

Ooops, sorry that $700 is only for the TCU, the PCs web site says that most wiring harness is mostly $150?

[gmctd]

TCI is another - and which may be reviewed in the 6.5 Ptoject Book - they'll all be about the same pricing, tho

[borneo]

Thank you gmctd. I also had bought Bobbie DB2 conversion manual.
What a great forum with great peoples like you guys!

borneo