• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Old 6.5-T strikes again !

Status
Not open for further replies.
Now after letting the sample sit a while i have what looks like a very small amount of what looks to be sand.

There is 3 water bubbles at the bottom.

There is what appears to be dust type paritcals floating threw the center of the fuel sample.

Mikey
 
There is bound to be a little crud, thats what the filter is for, and youre getting unfiltered through there.

So we know you have some iffy fuel still.

Next and the reason you need a good LP is to prevent the lack of pressure from causing bubbles and IP strain. This is why youll need a cheapy vac/fuel pressure guage attached to the fuel drain hose while running the truck. If you have low pressure could be a restriction/clog causing the fuel to get bubbly before it reaches the IP. And you can monitor the pressure while it idles and when it starts to hiccup is it because pressure went down.
 
Well yes i am sure the iffy fuel has been there the whole time from start to now i only got 60 miles on that tank of fuel. . .

problem started at 1/8th of tank i filled it up added the 911 ran a day changed the lift pump n filter burnt a 1/4 tank leaving me at 3/4 when the truck refused to run any more.

I am currently at 5/8ths of a tank of this fuel. the truck only started when i drained the canister n filled it up pouring some 911 directly to the filter, had to feather it to keep it running. any steady throttle it would start missing. . .at idle i would stall out dead as tho you shut the key off.

Once the engine got good n hot it would idle on its own but it was unsteady it kept floating between 500-750 rpm. . .

Mike
 
Definately need the pressure tester and monitor it, which means you need a long enough diesel fuel line to go from valve to the windshield or some people tape the guage up to the drivers mirror. Ive had one taped to my windshield wiper before.

Just for your information...floating RPMs can also be caused by a faulty Engine Coolant Temp Sensor, but dont want you to think I am recommending you go replace it. The ECT is just a thermistor, so if you jumper the harness with a radio shack 300ohm resistor the PCM will just run the truck as though its 180*F. Its just one other diagnostic method, a shot in the dark perhaps, but not what Id call trial and error, as you arent spending much money or time to do it. Like pulling out the Fuel/engine shutoff, its supposed to be a 10 min test, until your fingers are too big to get the damn connector harness back together :)
 
i'll fix the goofy idle another day. . .i don't much care about that at this really it means nothing i guess. . .

I in 12 years of driving haven't ever need a pressure gauge before, which is prolly why i don't have one or maybe i do but i have no idea where so its just safer to say ain't got one and with 8 bucks to my name at this point i ain't going to be able to go get one.

So i guess this truck is just going to be a pile of junk sitting on a trailer in the street until i get some money then. . .

Mike
 
even on my gassers and carb'd engines have needed to measure vacuum. Vacuum is more important on them actually. Its only used on the 6.5 for the turbo setup, and EGR valve operation if you have it. On a gasser it will cause all sorts of fueling issues.
 
I am not saying i don't need 1 guy i am saying i haven't had an issue where one was needed before.
I am sure in due time i'll use it on them all at some point or another.

Are the words " I AM BROKE " that hard to understand ? " I HAVE NO MORE MONEY " are those words easier to read ?

If i had your millions by gosh i go to the local farm n barn and buy 5 of every tool they got. . .but i don't so i can't !
so i can only buy things when i have the money to.
this go around i bought a lift pump and a fuel filter that is was all i had money for.
Next week i can buy a Pressure gauge and then go from there.

the work season just started so i won't have much cash for at least another month then i can spend like MAD but until then i'll have to continue on limited funds.

Mikey
 
JiFaire told you in post NUMBER 2 to check fuel pressure.

You went out and bought a lift pump.

If you listen more to what these guys are telling you to do to fix your truck, it would be fixed by now.

POST #2.
 
If i always listened to what folks said i wouldn't have bought a GM diesel period dot :thumbsup:

My father and my uncle both gave almost an hour long lecture about how stupid i was for buying a 6.5 diesel. they pretty much told everything that has happened would happen. . . as they have both delt with them in the past and they clearly stated they would NOT help me at ALL on this truck.

My uncle said: "you should have gotten the 350 but even the 454 would have been a wiser choice" " 6.5's are great till they get sick once they never really recover and keep breaking more often with each repair and the prices of each repair continue to increase "

My father said: " if you wanted a diesel you should have gotten a Cummins "
" I would have rather seen you buy a Ford " "when that thing breaks its going to cost money " " when the 6.5 turbo fails it tends to break multiple parts at once " " you have 1 simptom that requires multiple repairs to fully solve"

So as you can see if i did as i was told this spur of the moment truck wouldn't have been bought. . .



Mike
 
Last edited:
Oh i bet i haven't told you the story of how this truck came to be did i ?
Well here it goes. . .

I was coming back from oshkosh with my old Ford F150 5.8L V-8 E40D 4 spd auto 3.55 gears n 33x10.50R15LT TSL super swamper radial a howling the tranny had been go for a bout a year year and half i hadn't intended on replacing the trans. well on this trip home towing my car trailer emtpy the trans puked i got walked 1.5 miles on the Lenz truck dealership walked around the lot saw the old GMC 2500 sitting in the corner gave it a look see. sales man came up to me started yacking about it. i said dose it run ? will it tow car trailer hualing another pick up truck ?
he yes it will. . .
I said sold i signed on the dotted line swapped insurence over the phone and walked out the door. jumpped in the beast picked up my truck n trailer and headed on home to madison. . .

there was know test drive no haggling it signed for and driven away with. . .

Mikey
 
Understand you are broke, just sell that silly 92 TA :)

So Dad was right, but at the same time its going to be a self-fulfilling prophecy by junking the truck and not learning the few things that are really important for it compared to a gasser.

GM technicians have given it this bad reputation, for their ignorance, and GM engineers not addressing the one major PMD issue. GM was stupid on this one all around, and thats why these forums are big, because people got burned by a mechanic when they thought they had a great diesel truck.
 
I'm just saying they both tried the 6.5's and after a few dozen trips to the repair shops the old man went back to Gas n Cummins powered fords. . .My uncle went back to 350's n 454's . . .

I gave the 6.5 a try and it bit me right on the tail feathers, as they said it would.
Plus you have to figure this truck was only really gotten as a ride home as it was faster then waiting on a tow truck or another one of my Rigs to drop what they were doing and run up n get me.

So it really has served it intended purpose so crushing it is really no sweat off my nose.

I perfer to run the truck till its dead, it would suck to just up crush this truck. But i will if i have too. . .




Mikey
 
Sell the TA to fix the 6.5 :eek: . . . If i sold to TA for the GMC the 6.5 would be history and id be dropping a 5.9 or 6.7 Cummins into it. . .for sure :thumbsup:
But that is just not going to happen. I aint going sell somthing nice to fix up a beater :mad2:

Anywho i guess until i get some more funds this truck ain't going anyplace with out some more new parts i guess. . .
So about that check list for testing the PMD ? I am going to try and snag my meter tonight. . .

Mikey
 
I posted that list of what voltages should be where and when. there is no prescribed test or checklist, only an I/O function check. Its really just info for those that know what can be done with it.

There are a couple you can check with the PMD unplugged and probe the harness. However, to test if the PMD is outputting a strong enough signal it has to be running.

That involves starting up the truck and probing through the insulation of the wire that runs to pin B of the PMD. That is the PMD output to the IP fuel solenoid. Make sure the meter is set to read AC voltage on this signal. At idle as written in the document you should see 1.6VAC. If the voltage goes up fuel output goes up and RPMs, so if someone hits the pedal thats what you will see, up to about to almost 5VAC if you really rev it up past 3000 RPM. If the truck goes into some stumbling idle and the PMD is still outputting 1.6VAC then it isnt the PMD stumbling, and youll likely see the PCM command the PMD to a higher voltage to try to keep the truck running.

Although this does check the functionality of the PMD, its not a reliabilty test, so the same PMD that starts a truck could overheat and die 10 miles down the road. What I would use it for mainly is no starts, but can be helpful in a situation such as yours if youre comfortable with a meter.

At some point I might write that up in an actual procedure, but telling people in any official capacity to probe through or cut away some insulation can be dangerous if people arent familiar with multimeters and electronics.

I personally trimmed away a little insulation and hooked a small spring loaded clip meter lead and monitored from inside the cab while also watching the scanner reading out the fuel rate and injection pulse width. I verified my Dtech PMD outputs the same as the Stanadyne. Then I filled in the insulation with some liquid stuff that dries up.
 
Seems like a simple enought test tho wouldn't simply unplugging the PMD and trying to start the truck do the same thing ?
I had it running for about an hour or so today it ran like crap but it ran none the less. . .It would just be easier to just buy a new one or good used one. . .know to be good. . .

Mikey
 
well yes, the simple test for the PMD is, have a spare that works and plug in the spare.

Thats what everyone recommends, and then some people buy a PMD and it doesnt fix their issue, but at least they have a spare we'll say, not for nothing.

Knowing how something is supposed to work and communicate is how a real diagnostician can fix problems without being a parts swapper mechanic.

I am an overly curious person, and it is my job to find problems and fix them and explain why something failed, so Im not usually happy enough with the its magic explanation.
 
Well i am sure this is only the begining of this trucks issues, best i can tell it about puked !
The truck is pouring oil into the intake is leaking bad enough it blowing it threw the Rubber sleeve the connects the air box to the intake.

I just don't see this motor having to many miles left in it.

Mikey
 
Fricken great i left the fuel cap off while i had it running and between running back and forth it got rained in. . .Now i am sure its really Screwed up. . .

Mikey
 
Yeah mentioned that oil is common, its because of that tuna can "CDR" (PCV) thing, and the vacuum of the intake sucks the oil out of the valve cover. Just plug that intake hole and let the tuna can vent to air. Its a piece of crap system to "burn" the fuel vapors from engine blow-by, or a "closed" PCV system for pollution control. If you let it vent to atmosphere its an "open" PCV system.

Ive contemplated just putting a regular old Valve Cover Breather ($10) on instead.
 
Status
Not open for further replies.
Back
Top