6.5TD coughing and stalling ?!?!?!?!?!?

[M123KT-450]

My 6.5TD "Coughs" from time to time other times it'll "cough" than stall out dead a few miles later. Some time it will just die at randum fire right back up "cough" within 50 yards of where it stalled and run fine for several days.

Cough = felt like you stabbed the brakes.

A sharp hard jerk it comes jerks and rolls along as tho nothing happened.
Not sure what it is but its getting very Annouying and i'm starting to get nervouse to drive it anyplace as i don't want it to stall and NOT refire up.

things i have done:

1. Treated the Fuel for water n gell.
2. Replaced Fuel filter and blead air out of system.

Any thoughts ?

Mike

 

[DEERE3594]

Have you checked/cleaned your grounds?

 

[JiFaire]

Hi Mike.

We need some more information... mind taking a few minutes and filling out the Diagnostic Checklist? Click onthe link in my signature, copy the checklist into your next post in this thread and put the answers in for every question you can respond to... just click in the blank and type.

That will help us get a better 'picture' of your truck and what the symptoms are, without guessing or asking 1000 questions.

Guaranteed, this is the best place on the net to get help with your 6.5!

Jim

PS - I'm assuming it's the 1995 in your signature?

 

[JiFaire]

And yes, it DOES look like it's the obvious problem again, but let's get some data first, guys? I hate sending anybody on a parts-buying-spree.

 

[M123KT-450]

yup thats the truck alright had it 3 months made 3 payments only got 39 payments to go i'm hopping the truck will last that long.

Mike

 

[DEERE3594]

yup thats the truck alright had it 3 months made 3 payments only got 39 payments to go i'm hopping the truck will last that long.

Mike

It will :thumbsup: LOTS of guys much smarter then me here :smile5:

 

[M123KT-450]

Problem: Explain your problem in concise language (ie: Cranks but won’t fire). _No___________________________

Demographics: tell us about your truck and your ambient conditions:

- Year: _1995_____
- Truck model and class (ie: c2500) _K2500________
- Automatic or Standard ___auto_______
- Mileage: (indicate miles or km) ___129K MI______
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) __starter fuel filter_________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? __turbo____________
- Ambient outside temp: (indicate *C or *F) __20-40*F________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) _________
- What fuel additives are you using? _ainti water/gell White bottle__________
- Where are you located? ___WI__________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter ___?______
- Fuel filter ____24 hours_____
- CDR Valve? __?_______
- Coolant – last flushed/replaced at ___?__________
- Oil – synthetic/regular, changed at __AMSOIL syn 1,200MI ago_________
- Batteries – state of charge, (matched set) replaced at _optimas 800CCA 2006____________
- Battery cables and grounds (removed, cleaned and tightened): _New 72hours ago 2GA_____________
- Glow Plugs - how many miles on them? ______?___ What type? ________?_____
- Injectors - last changed at _____?__________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? __Drive back form dropping a load of firewood off 1-MO ago____________
- How was the truck running fine before this problem appeared? _yes____________
- Has this problem ever happened before? ___twice now yes____________________
- Describe any related factors that might be part of the problem. ___none___________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) __Y__ And? __Nothing______


Diagnostics:

1] Starting:
1a] Does the engine start? ___Yes______
1b] Does the engine crank over? ___Yes_____
1c] Are your batteries fully charged? ___Yes______
1d] Have you removed, cleaned, and tightened all battery connections? __yes______
1e] Does your Wait to Start light come on for a time? How long? ___yes______
1f] Does your glow plug light come on? ___yes______ For how long? _30-45seconds min________
1g] Do you see smoke from the exhaust while cranking? What color? _no_______

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? __yes__________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? __yes_______
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? ____?_______
2d] Loosen an injector line and crank the engine - does fuel come out? ____?_____
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? _Rarly__________

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) ____?_______
3b] Condition of Extension harness (if used) Vendor or Homemade? __?_______
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. ____?_____
3d] PMD Make: ___?________
3e] PMD Age: _____?________

4] Stalling Issues
4a] Do you experience stalling only when hot? __yes__________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) _No_____
4c] Does pouring cool water over the IP seem to help with restarting? ___?______
4d] Is stalling momentary (engine recovers)? _Normally yes________
4e] Does SES light come on when engine hiccups? ___No______
4f] Does cruise control quit working when engine hiccups? ___?________
4g] Does re-starting seem to reset engine, restoring cruise and power? _Yes________
4h] Changes to dash lights or instruments during stalling events? __Dims_________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? ___?____
5b] Any bubbles or oil film in coolant overflow tank? __No_____
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? ___No_______
5d] Excessive white smoke from exhaust on cold start? __No_______
5e] Excessive black smoke from exhaust under hard acceleration? ___No_______

6] Performance Issues
6a] Do you have gauges? ____Yes_______
6b] Maximum boost under load? __?__________
6c] Have you added a performance PCM (reflash) or Chip? ___No___________
6d] Have you changed exhaust / downpipe / crossover? ___No_____________
6e] Wastegate – mechanical or vacuum? _____?_________

7] Temperature-related Issues:
7a] Single or dual thermostats? __?__________
7b] Have you replaced them lately? Manufacturer of replacements? ____No_____
7c] Have you pulled and cleaned Radiator and coolers lately? __yes__________
7d] Have you replaced the fan clutch? Manufacturer of replacement? __No______
7e] (winter) Have you tested your antifreeze? Good to what temp? _____ -50______
7f] (winter) Are you using a winter grille cover? _____No______

 

[M123KT-450]

I used "?" for what i didn't know. The problem first showed up around a month ago it up n stalled out wouldn't restart got it towed home truck fired up right after tow truck pulled away:mad2: has ran Perfectly for sebral weeks in the last week it stlled out refired i was like OMFG not again but truck refired almost instantly as nothing happened, ran 50 yards "coughed" or "Hicuped" but kept right on rolling this time went a few days hicupped again tonight on the way to help a friend as pulled into his driveway truck idle a few seconds and shut off, hit the key truck refired as tho i shut it off which i didn't let it idle a good 5min and shut it off ran great the rest of the night.:mad2:


Mike

 

[DEERE3594]

The PMD is the Pump mounted driver (aka FSD/fuel solenoid driver)- common failing part. Stock location is on the side of the injection pump. Failure results in stalling... Is your still on the pump? Would be on the drivers side. its black, about the size of a pack of smokes...

 

[JiFaire]

Hokay, Mike, we need to get trained up on a few things to look for.

Let's start with the obvious: PMD. The PMD is a black electronic module, about the size of a deck of cards, that is bolted to the side of your Injection Pump. The IP is located on top of your engine, slightly to the left of centre, at the front, by the oil-fill-tube.

Have a look in there and see if your IP has a PMD bolted to it; while you're looking, see if you see another one on a heat-sink bolted to the top of your engine, or under your front bumper.

I'll attach a few pictures for you in a minute. (guys, we really gotta do some work on a picture thread...)

Hang in there.. I'll be right back.

 

[JiFaire]

Here's your IP - the black thing on the side with the wires is the PMD (stands for 'Pump Mounted Driver'... it contains the transistors that make yout injection pump inject diesel at just the right time.)

 

[JiFaire]

This thingy is a VERY common problem... if it's mounted under the hood; heat kills 'em. We discovered years ago that when it craps out, that the symptoms are the same as the ones for dead IP (which is what GM always wants to change, at $2-3000 a pop), but that by putting in a new PMD (if that is the issue) and mounting it out of the engine bay on a good heat sink, we could eliminate the problem.

Let's see if yours is still under there, OK? If it is, and if it is hooked up (and not replaced by one mounted elsewhere), that is likely your issue and we have suggestions on what to do with it. Also lots of other things to test before you spend anything.

 

[buddy]

The jerking is caused by defueling, and yes it can be violent. The PMD is the obvious choice as said. The PMD tells the IP when and how long to shoot fuel to the injectors and its common failure item.

Should be a main sticky about this stuff......

 

[M123KT-450]

Never seen that never looked for it either.
There is a big black unit with cooler fins on it mount right to the top of my engine i think itsays FSD bla bla somthing Cooler. . .

I don't have and won't have any money to invest into this for while so i'll have to suffer threw it.

Mikey

 

[buddy]

It may not be too bad then. Pull that heatsink off the intake, find the right torx or allen driver and tighten the screws that hold the black box/PMD on. Or even better would be to take it off and apply new thermal grease and tighten the screws as much as you can. See if the PMD/FSD has Standadyne on it anywhere. If you remove the PMD/FSD then you can go as far as tightening the nuts that hold the two 500W transistors down.

Its a Pump Mounted Driver (PMD) but when not on the pump people call it the Fuel Solenoid Driver (FSD) since its not on the pump.

Also, make sure that ground wire on the side of the heatsink is tight, but you really want to add a wire from the side of the heatsink back to the bolt on top of the IP or even down to the engine ground below the heatsink. This grounding may be your only problem.

According to the people that make those heatsink kits you need to tighten the bolts every 3k miles. And according to everyone on this site you need to get it away from the intake. You can by a cable that is long enough to put it in the bumper where it will be cooler, but youd have to weatherize the PMD/FSD. PMDCABLE.com

If you have a stanadyne PMD/FSD then there are aftermarket PMDs (i.e. D-tech) that are better (higher heat rated components) for like $180 on ebay, or you can find used tested ones for like $30 there. Its good to have a spare becuase it could leave you stranded no matter what kind it is or where you put it.

Your problem will only get worse if you dont do anything. Try tweaking the bolts and adding the ground wire at a minimum.

 

[Burning oil]

If the PMD/FSD is mounted anywhere inside the engine bay it will actually run hotter than if you just leave it on the IP.
Mount it anywhere outside the engine bay and it will run 10 degrees over ambient temps. We did a bunch of testing on this a few years ago and that is what we would see.

 

[JiFaire]

'Morning Mike.

Congratulations. You have an SSDiesel-no-warranty-mostly-works-then-dies FSD Heat-sync. Mounted right where they insist is the best place. Wrong.

As Buddy mentioned, your problem is gonna get worse - so you should try doing some things now.

1 - make sure the ground wire is fastened to the top of the IP where it's supposed to be. Where SSDiesel wants it (on the heat-sink) is just wrong. Period.

2 - As buddy mentioned, get some Arctic Silver Thermal Grease from Radio Shack, remove the PMD from the heat sink, turn it over. On the bottom are 2 plastic caps, covering 2x500-watt transistors. Pull the caps off (and throw them out). The transistors each have 2 nuts on them... loosen then with a nut-driver, tighten them back up to 10-inch-lb torque (contact + 1/4 turn), then smear arctic silver over the mounting surface between the heat-sink and the PMD, and re-attach the PMD to it. Tighten it down REALLY tight... good contact helps the PMD transfer heat.

3 - Get an extension cable from Leroy (pmdcable.com) so you can move the whole thing out of the engine bay, behind the bumper, to keep it cool. Leroy's cables are good, and they're cheap... can't go wrong.

4 - Get a replacement PMD when you can. DTech is just as good as stanadyne, lots of guys here run them with no issues.

AVOID buying 'used-but-good' PMDs. There is no way to test a PMD to see what kind of accumulated damage has been done to it, despite what EDAM of quebec tells you on EBAY. All you're doing is buying somebody else's problem, and you just saw how that worked out, right?

Let us know how things work out. Welcome to the site!

 

[M123KT-450]

So what you think about making it the worlds most expensive Trailer ? LOL ok ok

so these 2 units ( i think theres 2) on the top of the intake manifold must be moved else where ?

Now the Bumper is not a good idea for me really it'll be shot in no time once the spring thaw hits as that bumper i'm sure will get submergered or close to it, The F-150's bumper cleared just fine but it sat a good 3+ inches taller.

I personally think i bought the wrong truck and this Diesel is just plain NOT for me but i'm stuck with it for a while so i'll have to make due.
This truck don't know how bad i want to Crush it right now:mad2:

After the laundry is done drying i'll head out there snap a few photos of what i got now i think that'll be way easyer than trying to figure out what all that Lingo and jargon means.

I guess what i'm hearing is the truck is of Piss poor design and to Never ever buy a GM diesel truck again once this one wears out.
Truck was always dealer serviced so everything on it is stock n factory and GM approved, so if it is all wrong and i have to redo it to kepp the Wreck running than i would consider that a Bad design

Mike

 

[bison]

So what you think about making it the worlds most expensive Trailer ? LOL ok ok

so these 2 units ( i think theres 2) on the top of the intake manifold must be moved else where ?

Now the Bumper is not a good idea for me really it'll be shot in no time once the spring thaw hits as that bumper i'm sure will get submergered or close to it, The F-150's bumper cleared just fine but it sat a good 3+ inches taller.

I personally think i bought the wrong truck and this Diesel is just plain NOT for me but i'm stuck with it for a while so i'll have to make due.
This truck don't know how bad i want to Crush it right now:mad2:

After the laundry is done drying i'll head out there snap a few photos of what i got now i think that'll be way easyer than trying to figure out what all that Lingo and jargon means.

I guess what i'm hearing is the truck is of Piss poor design and to Never ever buy a GM diesel truck again once this one wears out.
Truck was always dealer serviced so everything on it is stock n factory and GM approved, so if it is all wrong and i have to redo it to kepp the Wreck running than i would consider that a Bad design

Mike

I have"nt found a vehicle brand yet that wont break down at times.Even new ones do,go look in dealer shops.
GM 6.5 engines are easy to work on compared to dodge or ford diesels,and cheaper too.

Here on the site you'll find vehicles with problems, it dont show the zillions of vehicles that never seem to have a issue or are dealer serviced. same with other brands.

so, dont get yourself all riled up about it,here advice dont cost a thing and you can learn something in the process.

 

[buddy]

This engine is easier to work on that many gassers and also cheaper, when you step back from it and think through it calmly. Although it may seem sensitive, it takes a lot of crap.

Yours probably works fine, just need to care for it. Put the ground on, might get rid of your issues all together but need to tighten bolts if they have vibrated loose at all. This is some real simple stuff actually. Its not hard or time consuming and costs you very little. Once youve done it its not a problem. You can mount it in the cab if you want, or leave it on the intake as long as you make sure the screws are tight when you change the oil.

JiFaires awesome with the pics.