Chevy 6.5 IDI randomly dies..

[R.O.R-2.0]

ok, so my grandpas 95 chevy diesel started to randomly die on me.. whenever i get on the power a little, then get back off of it, the thing dies.. usually when going up hills or something like that.

am i on the right track thinking that the fuel filter needs to be replaced?

it will start back up after a fashion..

maybe the lift pump is dead/dieing?

[maxfax]

Start with the fuel filter as that never hurts....  Could be a lift pump, but typically they either work or don't..  Could also be an oil pressure sender as that also controls the lift pump, but again they either work, or don't, usually..  I've seen the fuel lines coming off the sending unit in the fuel tank rust and get pin holes in them too..  But be prepared to replace the PMD..  

[Quantum TD]

I don't know much about those 6.2 and 6.5 motors, except that the PMD is a common fail point. There are re-routing kits to help keep them cooler and last longer.

I really want to get me a 6.5 Suburban.

[maxfax]

The relocation kit is worth every dollar!!  Aside from preventing future failures, it's much easier than yanking the intake and turning the IP to change these things..   I also HIGHLY recommend the D-Tech PMD over the Stanadyne one..  Even the most recent revision of the Stanadyne PMD doesn't seem to hold up like the D-Tech unit...

Kevin, check the other stuff to be sure, but I'd pretty much bet crucial organs that the PMD is taking a
crap..

You'd be surprised how many IP's get rebuilt on these things when it's just the PMD having PMS..  It's also surprising how many rebuilders don't replace it when they rebuild a pump...

[745 turbogreasel]

+1 PMD vote

[R.O.R-2.0]

Start with the fuel filter as that never hurts....  Could be a lift pump, but typically they either work or don't..  Could also be an oil pressure sender as that also controls the lift pump, but again they either work, or don't, usually..  I've seen the fuel lines coming off the sending unit in the fuel tank rust and get pin holes in them too..  But be prepared to replace the PMD..  

fuel filter is 2 weeks old.

lift pump is 3 weeks old.

PMD was replaced and relocated when we got the truck a few years back, its now under the front bumper..

[R.O.R-2.0]

isnt there a grey pmd, and a black pmd? he bought the black one.. idk if he knew you could get better ones.. he bought his off ebay.

its getting weird.. at first you would just have to hit the key and fire it back up..

now you have to crank and crank and crank, till it finally catches, then you have to pedal it till it smoothes out..

it will not idle on its own till you pedal the throttle a bit after it dies..

it has also been kinda hard starting ever since he did the last set of head gaskets..

[maxfax]

I think the latest Stanadyne revision is grey..  The earlier one's were black, as well as the D-tech ones....  Either one of those have the brand stamped on them..  If it's a black box with no writing it's a China knock off..

Has it flipped a CEL at all??   The speed sensor in the pump can cause hard starting and rough running, but it will almost always set the cel.. I'm still kinda leaning towards the PMD even though it is relocated and fairly new.. I replaced 2 Stanadyne units on the '98 I had within a few years.. Even with the relocation..  I found the D-tech module on ebay for around $200 and mine as well as a few other of these trucks haven't had a problem since..

[R.O.R-2.0]

lol @ CEL..

my grandpa says you have to get the computer reset to clear the codes, so its been throwing a code since weve had the truck.. hes a million-aire, but wont spend the few bucks to have the stealership reset the ECU..

so, yea, its constantly running with the CEL on..

usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..

[Quantum TD]

hes a million-aire, but wont spend the few bucks to have the stealership reset the ECU..

How do you think he got to be a millionaire?

The richest people I know do all their shopping at Walmart, Aldo, and the cheapest supermarkets in town.

[R.O.R-2.0]

he got to be a millionaire by working his ass off for 70 years, not pinching pennies.. lol.

they live comfortably.. but my grandpa refuses to spend any more money than he has to.. he re-uses his head gaskets hes so cheap..

when my grandmas cadillac breaks, it gets fixed to the fullest, not a cent spared.. but his own cars.. nah..

his caddy has worn out front suspension, and instead of fixing it, he puts new tires on it.

[maxfax]

usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..

That's screaming PMD..


'95 is still OBD1..  Chuck a paper clip in the ALDL terminals A and B, click the key to run, and the DTC's will blink out on the CEL..  It'll flash each code 3 times, starting with 12..  If you haven't done it before  you may need to read em a few times (Hell I still have to).. TO start over, turn they key off, wait a few seconds, and turn 'er back on..

The codes will be blinked out something like this:
 
For a 12  

Blink (short pause) Blink Blink (Longer Pause)  then it repeats 2x more times and moves to the next code..

 Pull the ECM fuse or disconnect the batteries for 10 mins to clear the codes...  IF you clear the codes, start the truck and the light comes right back on you have a hard fault for that component..

[R.O.R-2.0]

usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..

That's screaming PMD..


'95 is still OBD1..  Chuck a paper clip in the ALDL terminals A and B, click the key to run, and the DTC's will blink out on the CEL..  It'll flash each code 3 times, starting with 12..  If you haven't done it before  you may need to read em a few times (Hell I still have to).. TO start over, turn they key off, wait a few seconds, and turn 'er back on..

The codes will be blinked out something like this:
 
For a 12  

Blink (short pause) Blink Blink (Longer Pause)  then it repeats 2x more times and moves to the next code..

 Pull the ECM fuse or disconnect the batteries for 10 mins to clear the codes...  IF you clear the codes, start the truck and the light comes right back on you have a hard fault for that component..

does it matter any that its a non-egr engine, and that its in a 3500HD chevy dump truck?

my grandpa has no idea how to fix this thing, guess im gonna have to learn how to work on chevy diesels too..

[745 turbogreasel]

Nope, Chevy is about the best there is as far as not making  changes.

[maxfax]

Nope, Chevy is about the best there is as far as not making  changes.

Even when they should, and only when they shouldn't..   

Once you dive into it you'll find that pre OBDII GM electronics are cake..  Even the diesels..  Lord how I long for the days of their TBI....