Cranks, but won't fire

[sspence65]

Problem: Cranks but won’t fire

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

- Year: 1996
- Truck model and class (ie: c2500) Suburban
- Automatic or Standard Automatic
- Mileage: (indicate miles or km) 250k
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) original
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? Turbo
- Ambient outside temp: (indicate *C or *F) 50F
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) #2 diesel
- What fuel additives are you using? none
- Where are you located? andrews sc

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter K&N Cleanable
- Fuel filter 5000 miles ago
- CDR Valve? ?
- Coolant – last flushed/replaced at 10k ago
- Oil – synthetic/regular, changed at 3k ago (regular)
- Batteries – state of charge, (matched set) replaced at good
- Battery cables and grounds (removed, cleaned and tightened): new
- 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? driving at 30mph, rough road.
- How was the truck running fine before this problem appeared? smooth
- Has this problem ever happened before? no
- Describe any related factors that might be part of the problem. filled tank 30 miles earlier
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) yes And? 251 and 370


Diagnostics:

1] Starting:
1a] Does the engine start? no
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? 5 second or so
1f] Does your glow plug light come on? no gpl For how long? _________
1g] Do you see smoke from the exhaust while cranking? no What color? ________
1h] Does the Service Engine Light Glow during Start/bulb check? yes

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)? yes
2d] Loosen an injector line and crank the engine - does fuel come out? no
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? yes

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) pump
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: ?

 

[Pruittx2]

Was it running fine,, then just stalled, and now won't restart? Could be the PMD or the OPS As this is your first post, I hope you have done some reading,, also , you can use the search function above, for things like PMD and OPS,, and the technical library.

Your issue's will get fixed with help from friends here, as you have found the BEST site for 6.5's on the net. Weclome aboard, you will get questions about you situation, and we'll get you up and runing in no time.

 

[sspence65]

Yes, it was running beautifully, accelerating, when it felt like someone had just turned off the key. Coasted to a stop. I have been reading everything I can. I'm getting conflicting messages. One tells me I have contaminated fuel. Possibly, I had just filled up at a truckstop with high turnover, so not likely. They had no other reports of contaminated fuel. Another tells me my pump is bad and for $2500 they will rectify it. Possibly. I had a busted loose shutoff solenoid 6 months ago (and dropped all three pump nuts into the valley), but some jbweld fixed that and I tightened the nuts. Another tells me it's the PMD, but the codes don't indicate that according to a marine diesel mechanic. He's only seen the 6.2, not the electronic 6.5. I'm stranded 1000 miles from home with little money, and can't afford to guess wrong, or pay a garage. I have removed these units before, but never installed a new one, so I know what it looks like in the valley of death, but not much more than that. I'm in Andrews SC if there's anyone close by that has a clue.

 

[guybb3]

To clarify, you said you're getting plenty of fuel from the t-handle but none from an injector when the line is cracked and the engine is spinning?

 

[Dieseldad97]

Welcome to the site Steve.

Sucks when you have to join a forum.....usually means you need help.

From reading your report, it looks very much like a dead PMD. It would be nice to try one before buying one because they are between 175-250 bucks. The best thing to do is grab a coffee and search PMD to gain some more info.

Keep us posted. Good luck man!

 

[mangus580]

PMD was my first guess too when I talked to Steve this morning. I wish I had a known good spare... but it seems all my extra's are now duds :-( (although I have yet to test them myself)

Hmm... now that I think about it, I might have an extra functional, if I can find the pump in the snow! (bad pump with unknown pmd) If I can find it and it works, I will send it down to you! IM or email me your addy.

 

[buddy]

You have the OS codes. Try unplugging the Optical Sensor (OS) on top of the IP, crank it. Plug OS back in and try cranking. And then try unplugging the Crank Sensor which comes up by the IP and try cranking. If it runs with either unplugged it will be in backup fuel aka "limp" mode.

You should be using a lubricant additive in your fuel, ULSD will kill the IP over time, 1-2 quarts of SAE30 non detergent or a 1/2-1 quart of TCW3 2-stroke oil.

Bad fuel, could be cloudy, or too dark and cause OS to not work. But if you have checked for flow, you could also see if it looks dark.

 

[sspence65]

I have fuel flowing from the filter, and it's clear. No fuel at thr injector while cranking. I can't get to the IP without removing the blower hood. Wiring looks cracked from heat and skanky.

 

[buddy]

You should be able to reach the top of the IP to disconnect the OS harness, without removing the upper intake plenum. Take off that silly turbo power cover if thats what you mean.

 

[sspence65]

I was referring to the air intake from the turbo to the intake hood that bolts to the intake manifold. It blocks most of my access to the IP. I also have A/C lines crossing there as well. I dumped the plastic cover a while back.

 

[buddy]

From the passenger side you should be able to get your fingers under the upper intake plenum to the top of the IP to pull off the OS harness. Since the themostat and radiator hose might be blocking on the drivers side. Should fire up in limp mode if you get it off.

 

[fonecop1]

I would draw about a gallon of fuel out of that T valve and let it sit in a jug and see what it looks like. Still sounds like PMD but to check the fuel good is free. I got a bad tank of fuel several years ago at a truck stop right on the interstate and made it about 30 miles then dead and would not refire. Just like you the truck stop said nobody else had complained, when I called back later I finally got another clerk to tell me that there were other people complaining. Luckily I used my card for the purchase and had the receipt, they wouldn't do anything if I didn't have that receipt. We sifoned a few gallons out of the tank and this stuff wouldn't even burn with a direct flame. Truck went to dealer and I drove a rental car.

I found an old PMD in my garage but I don't know if it was the one that died hard or the one that just died occasionally or I would send it to you for testing/verification.

 

[buddy]

The only thing that sounds like a PMD is the "it just died" but the two codes point directly at the OS in the IP, which also can cause it to just die and not start and get no fuel.

Bad fuel is certainly possible, and so is a bad IP. Most people wont just replace an OS. Does the water in fuel light work when you first turn on the ignition? Water, air, or contaminants could cause the problem.

Do you know that the codes are current, and not historical codes? If they are cleared, do they come back when cranking?

 

[sspence65]

The codes come back during cranking after clearing.

 

[buddy]

Then you have some issue with the IP.
(1) the OS on the IP has gone bad, it is possible to change just the OS, but a shop probably wont do it. Will install a whole new IP.
(2) the fuel has something funky and is not clear, maybe water or you have air leak, possible since a recent fillup.
(3) the connector on the OS is loose, but would probably also get P0182
(4) the 5 volt reference from the PCM is not making it to the OS, it got shorted or broke. This is a gray wire that goes to pin A of the OS connector, there should be 5V when the ignition is ON, doesnt need to be running. Pin D is the ground for the sensor, so there should be 5V across those pins.
(5) the Crank sensor is actually malfunctioning and when compares it to the OS timing signal it believes the OS is wrong. Its good to start by unplugging these independently, because it should start and run with either one working.

 

[guybb3]

Good advice from buddy. Also when I had the 0251 and 0370 it was definitely fuel related and I find it telling that you had just fueled up the truck.

 

[sspence65]

Unplugged the OS, engine will still not fire, no smoke from tailpipe. Spray a little carb cleaner into intake, the engine chuffs like it wants to start. pulled oil filler, can see gears turning. will check voltages on connector. where can I get a wiring harness for the ip and sensors. the wiring in the valley and around pump is heat degraded.

 

[sspence65]

still no fuel from the loose injector line.

 

[Mudbath]

Unplugged the OS, engine will still not fire, no smoke from tailpipe. Spray a little carb cleaner into intake, the engine chuffs like it wants to start. pulled oil filler, can see gears turning. will check voltages on connector. where can I get a wiring harness for the ip and sensors. the wiring in the valley and around pump is heat degraded.

Stealer or auto salvage.

Be very careful spraying anything in intake with glowplugs enabled. But shows that it is only lacking fuel, points toward PMD.

 

[JiFaire]

If your PMD is currently mounted on the IP, and you are going to change the IP, this is the best possible time to remote-mount your PMD out of the engine compartment.

Now that we've settled you are gonna buy a PMD and remote kit...

DO THAT FIRST - if it doesn't fix your problem, THEN change the IP. If it does fix it, you saved a whack of $. At worst, you're only out the money you would have spent on the new PMD kit anyway.

JMHO