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View Full Version : 97' 6.5l turbo shuts off at random



curbrider
12-14-2017, 07:58
so a few things to mull over is that this engine has been run out of fuel 3 times before. a few months before i swapped the motor into a different truck it started dying while both driving down the road, or at a simple idle. there's no rhyme or reason that i've found yet. as far as procedures i've performed personally,

1-dropped the fuel tank and found the sock on the sender unit was filthy. looked like algae had completely covered it. mind you the fuel tank im speaking of was from a different truck, but still a problem. i blew compressed air through the lines to clear any obstructions from the fuel tank to the fuel pump(disconnected the lines there as well before hand), i then disconnected the fuel lines at the fuel filter(back of the engine) and put compressed air through there to the fuel pump(disconnected at fuel pump as well). it was finally getting fuel to the fuel filter. took me a while to learn what the bleeder valve in the filter was and it's been bleed to the point that the top of my engine wont be dry for a while.

2- just in case the shut off solenoid was bad, i changed that out with a better looking specimen from another ip i had from the engine i changed out. i was pretty convinced that was my problem as when i inspected the old one. the wires very close to the solenoid were exposed. but the shut off condition persisted.(newer solenoid wires were fine)

i have cracked no fuel lines from ip-injectors. nor have i taken off any glow plugs or injectors. the truck starts pretty much every time. the only time i've had a no start condition is when i put the "turbo power" plastic cover back over the intake manifold. and that at this point only contacts the vacuum lines near a sensor they are plugged into at the back drivers side of the engine. it does not pinch the lines or anything, simply at best bends the lines a bit. but with the cover off, the truck starts every time and will run, but still shuts off at random. every now and then it skips a beat, and i havent been able to pull codes with an obd2 scanner i got at oreily's. incase you're wondering it's the $350 one that they currently have. still couldnt get codes off it. though it has been swapped from a different truck, i took all corresponding electrical with it. i mean i swapped out the electrical from the dash as well as engines. all original wiring kept in the truck is the grill, and body for lighting. that's it. otherwise all wiring came from the swapped motor truck. as well as the ecm. basically i have no way atm to check codes.

so a check list of what i need to do to diagnose this would be helpful as i am fairly ignorant to diesel engines. i've been a student for ast about a year now. i've been trying to do it on my own with direction only as needed. but my direction is now random as my teacher has limited knowledge of diesels. more often than not, i was directed to this forum whenever i ran into a wall on something, and not lying, this is my hail mary lol. if i had to take this thing to a garage, the wife is gonna make me sell it. I DONT WANNA. so lets start with a check list of things for me to do first. and then i can give definitive yes and no answers to diagnosis of this thing. any and all help will be greatly appreciated as i love my 6.5L. i went through the trouble of converting an automatic 2500 extended cab chevy to a manual and doing everything properly to make sure i had all bells and whistles necessary(clutch switch, steering position sensor, and had some funny business with the multi function switch). i've put alot of work into this truck and would like it to be my rolling resume for i need something to show for my education. im not even being trained on diesel. so hopefully that will show something to perspective employers. but at this point my direction is in you readers hands. so please. a top to bottom check list of things that can stop this thing from running at random like that is what im looking for.

Yukon6.2
12-14-2017, 10:07
Hi Curbrider
And welcome.
My first thought is that you have a PMD that is acting up.Especially when you mention the plastic turbo cover.Take that off an hang it on the wall till you either sell the truck,restore the truck or till recycling day comes around and place it at the curb with hard plastics.
Back to the PMD,it is a little black box on the side of your injection pump.They do not like heat,your turbo cover traps the heat in the engine valley where the PMD lives,the heat dosn't help the injection pump either.
The fix is to get a good quality PMD extension cable and PMD heat sink and relocate it to an area that will have air flowing over the PMD when you are driving,and somewhere that the heat dosn't build up when you are parked.
The next thought i have is Ignition switch.Do you have any other electrical gremlins? A new switch solved some problems my truck had,not starting was the last thing,but it would shut off for no reason.I had a jumper wire that would solve that for me.But my truck was a wrecker so it had numerous added solenoids for stuff.One time that it shutoff when i went to start it i noticed the solenoid wern't clicking when i turned the key on.So i jumper-ed the bank of solenoids with a hot wire and the truck started.I used this jumper for a few months till one day the truck wouldn't start.Changed the ignition switch and it was back to normal.
Since then i have come across more ignition switch problems in GM trucks so it is now a problem child on my check list.
So there are a couple of things to look at trying.There is lot's of info on this site if you dig for it.And others will come by and give you some more help.
Keep asking and we will keep trying to help.
Thomas

curbrider
12-14-2017, 10:36
only one more electrical gremlin to deal with. the horn. but i'll deal with that in time. the horn is useless if im not able to confidently drive the vehicle. i dont think it's anything to do with the ignition, as it persisted through the transfer from one truck to the other.

i did actualy have to finaggle with the multi function switch as the one that the motor came from was put into the new truck. it didnt have the wiring for the steering position switch, and the hazard light switch broke off in transfer. so i had to swap the wiring for the steering position switch into the old multi function switch, and another thing i had to do was to clip and rewire the ignition wires to multi function switch.

the green and brown wires with the lil plastic thing that wrapped around the ignition and plugged into the top of it. still dont know what it was for but i originally broke the one on the old truck in frustration, then finally figured out how it was extracted lol. anyway, i got the other one from the other switch in the new truck, wired it in, and all was good till i found the hazard lights wouldnt turn off due to the red plastic piece having broke off. so i had to basically undo all that i had done and redo it on the old multi function switch and add that steering position sensor to it. works fine now anyway.

also, a symptom that i forgot about when it shuts off on me. this was before i swapped trucks. but when i was driving, if it shut off on me, all i had to do was pump the fuel pedal and it would turn back over. basically jumped itself.

curbrider
12-14-2017, 10:59
although i've read about the idm in several other posts, i havent looked into it yet. is there any way to test it poor mans style? a dvom i mean, or something to the effect there of. not really made of enough money to simply buy a new one, nor the equiment for relocation. looked it up and the kit+new idm+new resistor costs just under $200. not sure if i would need to put in a new resistor or even where i would put it.

im currently tearing old parts apart to learn more about them. but this idm sounds like the possible culprit, as im sure it's mounted on the side of the ip and the rate in which it shuts off is more frequent when it's warmed up. but it's a 2-4yo injection pump and all the pumps im looking at on rock auto, even the $600 ones come with a new idm. that being said, im kinda curious wtf my mechanic bought cause he had me get a $1200 one... kinda rawr atm lol. anyway, more info to chew on.

Robyn
12-14-2017, 13:55
Hi

The PMD is not something you can check.

They work or they don't or at times they work until the get hot then quit...


AS mentioned, get a fresh one (Flight systems makes a good aftermarket unit.

Leave the old one on the IP as its nearly impossible to get it off without yanking the intake manifold off.

You can fish the cable off the PMD on the IP and the attach the extension cable.

THERE IS A RESISTOR that goes into the socket on the PMD and these have a number on them from 1-9

You may be able to use a small mirror and a flash light to get a peek into the socket on the old PMD...If not install a #5 resistor.

THEY ARE USUALLY GREEN and are cut to fit into the socket and go over the electrical pins.

They only fit one way.

The PMD is the first suspect on a stall/no start issue.

Mounting a good PMD cooler down on the front skid shield thats under the radiator is a perfect spot to keep the beast cool.

Be sure to use a good heat sink paste between the PMD and the metal cooler.

"Computer CPU paste" can be had at nearly any place that sells computer parts.

White greasy goop.

Good luck

arveetek
12-14-2017, 14:13
Erratic stall with no other symptoms is classic of a dying PMD/FSD. They fail regularly on these engines. I keep a spare one in my glove box.

You need to rule out the PMD before going any further. 99.99% chance that will cure your issues.

Casey

JohnC
12-14-2017, 19:57
If you have a scanner that can record data, have it record solenoid closure time. Sometimes when the PMD is causing a stall, the stall is preceded by a few seconds of erratic solenoid closure times. (The erratic times indicate the PCM is loosing control of the solenoid so it commands the fuel shutoff to kill the engine rather than risk a runaway.)

Robyn
12-15-2017, 06:25
In all the years of fooling with these beasts I have only caught one incidence where I saw the anomaly you spoke of John

I have seen the runaway scenario where the beast goes WHAAAAAAAAA HOOOOOOOOOOOOOOEY and howls.

These are quite thrilling...
Luckily the ECM WILL SHUT THE ENGINE DOWN ONCE IT OVER REV'S


Seen a mid 90's Burb galloping around a parking lot with coal rolling out the pipe and a mortified driver hanging on for dear life a while back.

He got it anchored with the brakes (Except the rear tires howling) and I ran over an screamed at him to turn off the key...

Luckily it did not cause a wreck..

Beedee
01-02-2018, 19:10
My 98 had this issue years ago.
It would just randomly shut off, no rhyme or reason.

Turns out that it was a loose ground.
In my case it was a the ground to the engine and it was on the stud that held the trans dipstick in place.
The nut was loose and it would loose ground and boom, dead.

It took me about an hour to find it. Cleaned it up and tightened it down and it hasn't caused any more problems since.

As far as PMD's, on my 3rd or 4th. Can't remember. I keep a spare in the glove box now.

strykerAKAmack
03-23-2018, 19:18
Mine just did the same
Finally got around to changing out front abs wheel sensor to get that back working . Fired it up no more abs check light , good to go pulled it outside and now 3 days later , cranks throws some smoke but won't catch , grab out spare pmd along with new resistor throw it in .......Still won't fire up ????
Still getting smoke but no joy , made sure pmd worked before it was needed .
Ground wire ? hmm

Robyn
03-24-2018, 06:12
If you are getting smoke you are getting fuel, which means the IP is working.

GLOW PLUG ISSUE

Check to see if you are getting 12V to the glow plugs.

Glow plug controller may have gone south.

If 12V present at the plugs during cycle, then plugs are bad.

The RH side can be accessed easily through the wheel well with tire/wheel off and rubber flap removed.

LH side is easy from the engine bay.

JUST AN FYI

Put some non cease compound on the threads of the new plugs when you reinstall.

TRY plugging in the block heater for a couple hours and see if the engine will start.

Removing the plugs CAN be easier when the engine is warm

DO NOT USE STARTING FLUID ON THESE ENGINES.

strykerAKAmack
03-24-2018, 07:03
Hmm.... glow plug controller most likely culprit as I changed all glow plugs
last year .
But I'm still getting the glow plug cycle and the corresponding voltage drop when they kick on and off .
will have to investigate

strykerAKAmack
03-26-2018, 14:43
Ok glow plug relay broke apart as soon as I touched it ,the drivers side lug broke ,
installed new one and still doa ,Im getting relay click, has constant power on drivers side lug but getting nothing across to pass side :(
Bad relay ??? or control wiring causing it ??
safe to jump lugs for a few seconds ? to see if heat at glow plugs?
thanks

Robyn
03-26-2018, 15:32
if you jump the two large lugs it will heat the plugs.

THE ONE is the 12volt input and the other is the feed to the plugs.

If the relay is clicking it should be putting power to the plugs ?????

One side is hot all the time.
Check between the other one and the neg on the battery with a meter and have someone turn the key to on position.
When the lamp is ON the lug should show 12 volts and you should hear and feel the relay CLICK

Not sure about this issue...

bmoeller
03-26-2018, 16:20
Fusible link in the wire going to the relay?