Water in Fuel Filter cut off fuel to IP???

[Turbo6.5]

1995 Chevy 3500 6.5L Turbo Diesel:
The truck runs geat, but last night it just quit, truck sat for a couple of hours and she fired right up as usual, got on the Highway and she just quit, I was able to start her back up 4 more times to get off at the next exit. pulled it over in a safe zone, let her sit for a minute and she'd start right up then quit, let her sit for a few more minutes same thing and then she'd just quit, over and over, finally called a friend and got a ride home, went back this morning got in and again she would fire right up run idle for a minute and thought it was fine, started moving again and got to the stop sign and quit. Before I went out last night I put $20 in fuel at the gas station, at the time there was a fuel truck pumping fuel at the gas station where I get my diesel, went to the family reunion and the hotel, left the reunion 3 1/2 hours later and thats when everything started, when she runs she runs great, no sputter, just quits. can there be water in the fuel filter and when she sits she'll start, do it again and she runs shorter and shorter everytime I try to start her.

[DaveBr]

This sounds like a classic PMD symptom.

[Turbo6.5]

This sounds like a classic PMD symptom.
Thank You Dave, I had someone tell me if there was water in the fuel filter then that would cut off fuel to the fuel injector pump?? If I leave it sit for a while, she'll fire right up and run good, then just quit and everytime I start it after that first time the running time gets shorter and then no fuel to the injectors, could too much water in a fuel filter cause that?? cutting off the fuel to the injectors?? Ever hear of that??...Pat

[JohnC]

Is the water-in-fuel light on? Have you tried draining the filter? Easy enough to tell if there's water in the fuel...

I agree with the previous poster; sounds like classic PMD problems...

[Turbo6.5]

Thanks John, No light indicator inside the truck goes off, I drained the fuel filter housing when I replaced the fuel filter today. the lifter pump is 10 psi and when I release the T-valve fuel pumps out great. Let me ask you guys one more question?? I loosened one pf the injector ports, when I turn the key, should fuel be sqirting out of the injector, or does it only do it when running?? tested the fuel lifter pump through the T-valve ok but what about when I loosen the injector to the piston??? One more thing I haven't checked yet because I am waiting for a friend to get home, is the oil pressure switch, can I hook up a tester to that when I turn the key?? (OK 2 Questions LOL)

[JohnC]

I loosened one pf the injector ports, when I turn the key, should fuel be sqirting out of the injector, or does it only do it when running??

Fuel should squirt only when the engine is cranking over. Think of fuel squirting in the same context as spark plugs firing on a gas engine. (It will be a very small amount; the amount of fuel to fire one piston once...)

[JohnC]

One more thing I haven't checked yet because I am waiting for a friend to get home, is the oil pressure switch, can I hook up a tester to that when I turn the key??

If the lift pump runs (reliably) when the engine is running then the oil pressure switch is OK. The oil pressure switch is not effective when starting. The fuel pump relay powers the lift pump when the starter is energized.

[Turbo6.5]

Fuel should squirt only when the engine is cranking over. Think of fuel squirting in the same context as spark plugs firing on a gas engine. (It will be a very small amount; the amount of fuel to fire one piston once...)
OK That that is running normally and doing exactly that.


If the lift pump runs (reliably) when the engine is running then the oil pressure switch is OK. The oil pressure switch is not effective when starting. The fuel pump relay powers the lift pump when the starter is energized.
OK Good, I was going to buy OPS then thought it might not be needed, when she does run the oil pressure is normal on the gauge in the truck, I removed the 3" hose on top of the injector and crank her over and fuel also squirted out of there too. I started checking connectors with a test light and so far everything is good, it is starting to look as if it is the FDM, I just hate to buy one for $400 if thats not the problem, because I cant return it if thats not the problem and I don't have it like that to just spend if it isn't the problem. the check engine light doesn't even come on when she just quits either?
Thanks John, I will mess with it some more and see what I can't find out, If I have to spend the money on a FDM I will as long as that is the problem, just trying to trouble shoot everything else first, if you have any other ideas I sure will check it!! Thanks again :)...Pat

[Robyn]

Any idea how long the PMD has been on the truck ???

Is the PMD mounted to the side of the IP or has it been remote mounted ???

If don't have any SES light or water in fuel lights showing then my gut feeling is a failing PMD.

A lift pump that giving issues will not normally cause the engine to just quit.

Low power levels when pulling is more of a symptom of failing lift pump or a bad Oil pressure switch.

The Oil pressure gauge can still read fine, the switch has two components, the contacts for the lift pump power and the parts that feed the oil pressure gauge.

The PMD gets warm and then the power transistors fail. Very classic symptom on these systems.

Get a new DTECH replacement PMD and mount it remote.

If the old one is still on the IP, leave it there. Use a remote heat sink and an extension cable (available from several vendors that advertise here at TDP or the internet)

Use a number 5 resistor with the New PMD unless you know what the original one is.


Just for good measure, check to be sure that there is not any water in the filter.
Normally the light will come on but, never hurts to be sure.

If you can get the truck to idle, open the drain valve up front and drain some fuel into a small container.

If there is not an water, then the issue is elsewhere.

Good luck and keep us posted


Missy

[JohnC]

Use a number 5 resistor with the New PMD unless you know what the original one is.

Just FYI, you can read the resistor value stored in the PCM with a scanner...

[Robyn]

Yup, sure can. :D

IF YOU have a scanner. :(

[Turbo6.5]

Is the PMD mounted to the side of the IP or has it been remote mounted ???
Yes it is still mounted to the side. How much does a system like that cost to do?? to mount it separately?? I will look on here and see how much they go for, Yes I checked everything else but that and exacly the way it's acting sounds to be the problem, I can start the truck in the morning and she runs great the first time then just quits out of nowhere, no engine light indicator nothing, just quits. No water in fuel or in the housing. I have a big tree job I am doing today and hopefully I can get back out there tonight to look some more. Is it difficult to remote mount one, I can't just buy a PMD and just replace it on the side, why do you remote mount it??
Thanks everyone for your help, I will hopefully be able to work on her some more tonight after I get home. :)...Pat

[Robyn]

Remote mounting the PMD gets it out of the hot area down on the IP.

You can't easily remove the PMD from the IP while on the engine.

Just reach into the area by the PMD with a narrow screwdriver and unhook the harness from the PMD.
Fish the wire harness up and out of the hole (Be careful and dont get too rough on the harness)

The Cooler "Heat sink" can be mounted over by the LH Battery or if you get a longer extension cable, you can mount the cooler down under the radiator on the swing down cover.

Some folks mount their cooler out in the LH "Nostril" in the bumper.

The big issue is to get the PMD out of the heat.

The DTECH PMD is an aftermarket unit that is a direct replacement for the factory one and so far has been far more reliable (been out for about 3 years or so now)

The remote mounting take only a short time to do.

Unplug the old one
Plug in the extension harness to the end you removed from the Old PMD
Locate and mount the cooler with the new PMD on it.
Plug in the harness and your set.

Be sure to use heat sink paste between the PMD and the cooler to help transfer the heat.

Good luck and keep us posted.

Missy

[JohnC]

Yup, sure can. :D

IF YOU have a scanner. :(

Not to beat a dead horse (to much...) but you can also measure it with a VOM if you identify the right wires on the other end of the harness.

[Turbo6.5]

OK I was out there checking connection plugs with a wire tester to make sure the glow plug relay was working, Yes it's working fine, one side stays hot, the other post clicks off.

[Turbo6.5]

Thanks everyone for all your help, All the trouble shooting has been done. It is the PMD and am ordering the the kit today, as soon as it gets here I should be up and running. Thanks again :) ...Pat

[Robyn]

Glad that the issue has been found.

Anymore, with the symptoms you were having, the PMD is automatically suspect.

Back in then "OLD DAYS" when the 6.5 electronics first came on the scene, we pulled our hair out with these things.

The dealers technicians had little clues as to what to do, and the aftermarket had not yet spooled up to speed with fixes yet.

Many a good 6.5 was traded off with low miles, all due to the failure of the PMD.

We had a lovely 95 Burb that we had ordered and waited for 6 months to get.

Had less than 50 K miles and had been in the dealer shop for 4 IP replacements.

This as I know now was simply the PMD failing. The truck was refitted with a fresh IP every time it quit.

We got rid of the rig after the last IP was replaced.

It was shortly after that time frame the the aftermarket started to take notice of these issues and thintgs started to happen.

Unfortunately it was not until fairly recent times that a good PMD replacement was offered.

Stanadyne did not do a thing (relatively speaking) to fix the problem until the last year or so.

Myself I will not buy a stanadyne replacement PMD at all.

I use the DTECH units, simply because they came up with a good fix and were the first to offer something good.

Stanadyne finally jumped on the band wagon after their parts sales went in the toilet.

Really sad that a large company has to wait sooooooooo very long to rectify a design flaw.

Had the PMD been located in the interior of the rig or in some other cool spot to start with, both GM and stanadyne would not have had such a black eye over this thing.

The story of the electronics on these trucks is long and convoluted so we wont go into it here.


Good luck and let us know how things go.

Missy

[Turbo6.5]

I sure will and Thanks again for all your help!! I came across this and it describes it right down to a T exactly what my truck is doing, it was described as if I had wrote it myself LOL : http://www.accuratediesel.com/nostart.html

This is what I ordered also and it will be here Monday :)
The Driver Remote remount kit is $279 and I also ordered the #9 resistor too for a total of $323 with shipping included:
http://www.dieselcare.us/OScart/product_info.php/products_id/55
I will definitly let you know mon-tues, Thanks again!!
Take a look and let me know what you think about what I bought?? :)...Pat

[Robyn]

Looking forward to hearing the good news. :)

Missy

[Turbo6.5]

It did it!! That was the problem, I relocated the PMD and everything, She fired right up, shut her down and fired up again with out delay!! I also put a #9 chip in it too and I don't I have ever seen the truck run so good, new fuel filter also and she is doing GREAT!! Thank you so much for all your help and because of it a $2000 job only cost $323 all together and that included shipping, Thanks again You guys are the best!! :)...Pat