Need help with 1998 Chevrolet 2500 Diesel - won't start
- Thread starter Christian P.
- Start date
Rot Box
Explorer
My money is on a bad OPS (oil pressure switch). This switch fails often on these trucks and if it isn't working the fuel lift pump will NOT turn on. 6.5's can run with a non-working fuel lift pump, but they are hard to start, they will die randomly, and they will surge at hugh RPM's etc.. This is often mistaken for a failing PMD/FSD. The OPS is located on the rearmost portion of the intake manifold on the drivers side.
Once you have a stream of fuel coming out of the fuel filter bleeder you're done--the system is primed--There's no guesswork, trapped air bubbles or anything else. On that engine I see no need to crack injector lines once the air is purged from the fuel filter housing.
If you CAN'T get fuel to come out of the fuel filter housing bleeder that is a sign that either you have no fuel in the tanks or the lift pump does not work. Check for this and if you DO get a stream of fuel you can move on to the next likely cause being either a failing PMD/FSD or worn out injector pump. Hope this helps,
Andrew
Once you have a stream of fuel coming out of the fuel filter bleeder you're done--the system is primed--There's no guesswork, trapped air bubbles or anything else. On that engine I see no need to crack injector lines once the air is purged from the fuel filter housing.
If you CAN'T get fuel to come out of the fuel filter housing bleeder that is a sign that either you have no fuel in the tanks or the lift pump does not work. Check for this and if you DO get a stream of fuel you can move on to the next likely cause being either a failing PMD/FSD or worn out injector pump. Hope this helps,
Andrew
FellowTraveler
Explorer
OPS?
I believe on his 1998 w/OBD2 the OBS has a redundant power connection to lift pump therefore would not prevent start-up if bad.
I believe on his 1998 w/OBD2 the OBS has a redundant power connection to lift pump therefore would not prevent start-up if bad.
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FellowTraveler
Explorer
Pump mounted PMD stay away
The PMD mounted on the computer controlled injection pump is the number one (1) failure part of all fuel system parts on the 6.5 TD, period.
I strongly suggest not installing the PMD (aka; FSD when installed on remote heat sink) back on the pump because of labor cost. Research, you'll find a remote FSD costs less and I can assure you it will last much longer out of the engine bay!
For better than a decade now it has been determined the Standyne driver location design "on IP" is seriously flawed. The fuel flow through the injection pump was to supposedly cool the PMD.
A BIG plus, it is far easier task to replace the PMD/FSD when mounted remotely on a sand alone heat sink, even better is two (2) or more setup like I have so you just unplug the failed PMD/FSD and plug into a good one and be on your way within a few moments.
The PMD mounted on the computer controlled injection pump is the number one (1) failure part of all fuel system parts on the 6.5 TD, period.
I strongly suggest not installing the PMD (aka; FSD when installed on remote heat sink) back on the pump because of labor cost. Research, you'll find a remote FSD costs less and I can assure you it will last much longer out of the engine bay!
For better than a decade now it has been determined the Standyne driver location design "on IP" is seriously flawed. The fuel flow through the injection pump was to supposedly cool the PMD.
A BIG plus, it is far easier task to replace the PMD/FSD when mounted remotely on a sand alone heat sink, even better is two (2) or more setup like I have so you just unplug the failed PMD/FSD and plug into a good one and be on your way within a few moments.
greengreer
Adventurer
Always check your grounds. That being said my money is on the PMD being fried. Has it ever cut off on you while driving? If so and it was like someone reached over and turned off the truck at the ignition (no stumbling or missing) then you can bet on buying a new PMD. As was already recomended, get a new unit with heatsink and extension harness. It not only makes the unit last indefinitely longer, it also simplifies installation ten-fold.
Check out thedieselpage.com's forums, best and most knowledgeable site for 6.5's IMO
Check out thedieselpage.com's forums, best and most knowledgeable site for 6.5's IMO
FellowTraveler
Explorer
Update
How about an update, is it fixed, or?
How about an update, is it fixed, or?
sorry as I said I was traveling for 3 weeks. I just got back this weekend, turned the key and it started just fine.
No clue what happened. It is much warmer today so maybe it was frozen water (if there is such a thing). Or maybe the air vent out? Or maybe it will do it again later...but at least right now it started and idled fine.
I have to leave again for the week so not much time to investigate more, but next weekend I will take it out for a drive, fill up the tank, and have the filters replaced also.
Well, back to square one. it does not run again. it started but then shut off after a few seconds.
A question - if there was air in the system, shouldn't it keep running once it's started? I am starting to suspect something else is wrong with it.
A question - if there was air in the system, shouldn't it keep running once it's started? I am starting to suspect something else is wrong with it.
Well, back to square one. it does not run again. it started but then shut off after a few seconds.
A question - if there was air in the system, shouldn't it keep running once it's started? I am starting to suspect something else is wrong with it.
let me re-read this thread again.
A question - if there was air in the system, shouldn't it keep running once it's started? I am starting to suspect something else is wrong with it.
let me re-read this thread again.
Revco
Adventurer
You gotta determine where the problem lies first. Check if the lift pump is working. Open the T-Valve near the Thermostat and supply 12 volts to the lift pump and see if it pumps fuel out of the open valve, if it does, then you've ruled out the lift pump. If it doesn't work with 12 volts, then look at the Oil Pressure Switch. If that's working, then look into the glow pugs and relays.
I don't know much about these 6.5's, but I did help a neighbor diagnose the issue with his 6.5 hunting rig this past winter, turned out to be a fusible link on a glow plug relay, but we went through all of the above diagnostic tests first.
I don't know much about these 6.5's, but I did help a neighbor diagnose the issue with his 6.5 hunting rig this past winter, turned out to be a fusible link on a glow plug relay, but we went through all of the above diagnostic tests first.
All right I took a quick look - there is fuel coming out the fuel filter at the back of the engine.
there is also a ODBC error code - P0126 Coolant Sensor
I am going to go ahead and order the FSD, looks like it would be good anyway to replace it.
there is also a ODBC error code - P0126 Coolant Sensor
I am going to go ahead and order the FSD, looks like it would be good anyway to replace it.
shortbus4x4
Expedition Leader
No, your symptons could be air getting in the fuel system. It will start and run for a little bit until the air pocket gets to the IP, then it quits and won't restart until the air is purged from IP and injectors.
FellowTraveler
Explorer
Fuel filter leak?
There are quality replacement fuel filters that solve the leakage problem in the original filter design, they have a separate "o" ring seal and more fuel capacity. The original design has a poorly fastened seal which is a known issue, many times the seal will dislodge from filter assembly and result in leak.
The coolant sensor for fuel injection system is located on driver side cylinder head would cause a rich fueling situation like when not running thermostats. The sensor at the thermostat housing is for the temp gauge in dash.
After fuel leak and sensor issue is resolved it may run, if not then the injection pump driver needs replacement!
There are quality replacement fuel filters that solve the leakage problem in the original filter design, they have a separate "o" ring seal and more fuel capacity. The original design has a poorly fastened seal which is a known issue, many times the seal will dislodge from filter assembly and result in leak.
The coolant sensor for fuel injection system is located on driver side cylinder head would cause a rich fueling situation like when not running thermostats. The sensor at the thermostat housing is for the temp gauge in dash.
After fuel leak and sensor issue is resolved it may run, if not then the injection pump driver needs replacement!
All right guys - thanks everyone for your input.
it turned out to be....
...
..
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the PMD/FSD - the electronic module attached to the fuel pump. I got another one with an extension cable, dig around for an hour to find the existing one and unplug the cable, plug the new one and voila!! Started right away.
thanks again everyone. Now I just need to see if this ODBC code is still present.
it turned out to be....
...
..
.
the PMD/FSD - the electronic module attached to the fuel pump. I got another one with an extension cable, dig around for an hour to find the existing one and unplug the cable, plug the new one and voila!! Started right away.
thanks again everyone. Now I just need to see if this ODBC code is still present.
FellowTraveler
Explorer
Good, see how one little black box the size of a cigarette box can become a PITA, anyway suggest keeping a spare too.
On line you can get OBD2 "CARCODE" scanner device controller for your laptop (32 bit only) then you can collect real time drive train data, check your codes and reset most settings etc. maybe $120.