Author Topic: 6.5 TD mechanical (Read 6785 times)

AdAm84 · « **on:** July 14, 2007, 05:53:02 pm »

Ok. The 6.5td in our suburban is nice. decient mileage, power, ect. but now the electrical gremlins are appearing. it will just shut off for no reason. we've been through all of the obvious things and have had it to several mechanics including the Dealer recommended specialist. they've put several parts in it and nothing solves the problem, which brings me to my question. has anyone or does anyone know how to do a conversion to make this thing mechanical. its not rreally alot different from the 6.2 so it should be possible. its an automatic transmission but i've heard that someone makes a transmission controler that doesn't use the PCM. just an idea to get rid of problematic electronics. all ideas would be appreciated.

andy2 · « **Reply #1 on:** July 14, 2007, 07:21:19 pm »

What year and series (1500-2500) is your suburban?What parts have been replaced?I work on these trucks and have sorted out many stalling issues.

AdAm84 · « **Reply #2 on:** July 22, 2007, 03:17:51 pm »

'96 1500 w/8 lug. We replaced the ignition switch recently. over the past four years we've replaced the PMD, boost sensor, and i believe the oil preasure sensor. The guy in our area suggested trying the cam position sensor.

andy2 · « **Reply #3 on:** July 22, 2007, 06:24:52 pm »

PMD's can last as little as 1 year so if yours is 1-2 years old it still could easily be the issue.Is your pmd mounted on the inj pump or on an aftermafket heatsink?These engines don't have a cam sensor only crank and one inside the inj pump.Neither of the 2 will cause an intermitant stalling issue.Does the engine stall only under load,hot or cold,low fuel level??

AdAm84 · « **Reply #4 on:** July 25, 2007, 10:39:19 pm »

The PMD is still on the inj. pump. if thats the problem them were gonna mount it on the heatsink. the truck usually shuts off right after you start it up, it revs a few more rpms then shuts off. then you have to waite a bit before it will start again. sometimes it will shut off while your driving. and its the same deal starting it. lately it has been running like crap with the check engine light on one day, and like a champ the next. and it still occasionally shuts off.

foxracer1 · « **Reply #5 on:** July 25, 2007, 11:15:04 pm »

Sounds like its running short on fuel.

andy2 · « **Reply #6 on:** July 26, 2007, 06:24:32 pm »

I would definitely check the fuel supply for both fuel pressure and to see if there is any air in the fuel.Air in the fuel and or Low fuel pressure shortens the life of the PMD and the pumps internals.Stalling usually won't turn on the check engine light so you may have another issue as well likely boost or EGR related!

AdAm84 · « **Reply #7 on:** July 28, 2007, 02:28:39 pm »

Yeah i figure the check engine light is related to the boost sensor. we might just try a new supply pump. thanks

vixentd · « **Reply #8 on:** July 31, 2007, 03:07:21 am »

PMD - best to buy them by the case!

bigblockchev · « **Reply #9 on:** August 19, 2007, 03:44:31 am »

I forget when they went to OBD2 but You can read the codes from the computer to get an idea where to start looking. If it is OBD 2 you can get a cheap code reader if it is OBD 1 you can do it with a paperclip across terminal A & B to momentary short the pins. You will need to count the number of long and short flashes that the check engine gives after you do this. Best to do a search on one of the sites like GMdiesel.com for the full procedure.
http://www.gm-diesel.com/diesel/vbull/forumdisplay.php?f=31
Without this info you are shooting in the dark by replacing parts. The PMD's are not actually that bad when remotely mounted. It is a real shame they put it back in the stock location as it is a lot of work to get it in or out of there much easier to replace if remotely mounted. I have a 95 diesel burb and quite like it as well. Generally I believe that the PMD going bad will not throw a code so that should tell you something else is likely wrong. The Map or boost sensor can give you codes but won't generally come into play until you are under boost, and it won't shut the engine down. If you are getting fuel out of the water drain tap at the front of the engine when the engine is running and it doesn't stall out then the fuel pump is probably OK . If you aren't getting fuel from the drain tap then either the pump is bad or more likely the oil pressure switch at the rear of the drivers side head is gone. This makes the Injection pump do all the work and sometimes the engine will cut out. Try some of these things to see if you get any results. Changing the Injection pump to the older DB2 from a 93 6.5 is not an easy task to figure out. If you do manage to get it working you pretty much have to be your own mechanic as the dealers will probably not be able to figure out what you have done to change things.

AdAm84 · « **Reply #10 on:** September 05, 2007, 08:47:47 pm »

we replaced the lift pump thats mounted on the frame rail, and the MAP/boost sensor. the truck runs like a champ. It was only like $120 in parts and an hour of my time.

AndyBees · « **Reply #11 on:** September 14, 2007, 10:50:44 pm »

I could use a some advice on the 6.5 GM Diesel.

I have been doing a lot of "window" shopping in Ebay and other places for a to learn about prices on used Motor Homes. I am set on a Diesel Pusher. Occassionally, I will see an RV with the 6.5 GM Diesel. It seems most of them have the 5.9 Cummins in HPs ranging from 190 to 300.

What is the typical HP of the 6.5 GM Diesel? Is it as reliable as the 5.9 Cummins? Or, is that mixing apples with oranges?

Any pointers/comments appreciated!

Thanks,
Andy

bigblockchev · « **Reply #12 on:** September 15, 2007, 12:10:29 am »

The rated Hp of the GM diesel is around 190. I would describe it as a medium duty diesel with about the same lifespan as a 350 Chev motor. The Cummins I would characterize as a heavy duty diesel better in heavy applications. Cheers Dan

AdAm84 · « **Reply #13 on:** September 15, 2007, 04:00:56 pm »

go with the cummins. the 6.5 isn't heavy enough for that. the duramax on the otherhand............. :twisted:

Author Topic: 6.5 TD mechanical (Read 6785 times)

AdAm84

andy2

AdAm84

andy2

AdAm84

andy2

AdAm84

AdAm84

AdAm84