6.5TD no start - research and testing taken as far as I can, next steps?

[97SubK2500]

Our '97 Sub K2500 shut down fine one day last week, and 24 hours later wouldn't start, not even when the engine compartment temperature was 94 degrees due to high outside air temps + sun. No combustion at all.

My wife had run the fuel tank to within two gallons of empty, and had then added about 8 gallons of fuel from a low-volume fuel station out in the boonies (might be good fuel, but I don't know). Engine ran strong & smooth for 50 miles after the questionable refueling, and it shut down normally.

Glow plugs and controller, lift pump, and timing chain / gears all replaced in last 10-15k miles. Truck has been running strong and efficiently since last repairs in November, 2004. Typically has been getting 15-16mpg around town and 18.5 -19.5mpg on the highway (cruising @ 65-70).

I read through the 6.2/6/5 diesel guide, and searched this forum before getting under the hood.

Here is what I found so far:

1. #1 injector does not seep any fuel after being loosened one full turn and three attempts at 30 seconds of cranking with full throttle.

2. All fuses in both the under hood and in-cab panels are OK.

3. Pulled and replaced the fuel filter after the injector testing - it has 10k miles on it and was dark brown, almost black inside near the center. The filter housing was 2/3 full of clear fuel when I pulled the filter. I drained the filter housing (all clear) before installing a new filter. Followed owner's manual procedure for replacement and air purging. Purging pumped a strong flow into the empty fuel can used to receive the waste fuel. Black specks in bottom of (new) red plastic fuel can, but not sure if those are from can, rubber filter vent hose, or what.

4. Tried cranking it over before re-installing the fuel tank cap - and it turned over & started for a few seconds, but died on its own.

5. Tried cranking with full throttle for 30 seconds, with no success.

6. Re-inspected the fuel filter. All clear, as was waste fuel from purging.

7. Lift pump sounds normal. Voltmeter dips as normal during glow plug cycling.

If I'm understanding the fuel delivery path, this indicates that there's an interruption somewhere between the fuel filter and injectors.

So, what could it be? Reading the 6.2 / 6.5 guide, it sounds like there's a "fuel shutoff solenoid" attached to the IP that could be acting up.

Any advice appreciated at this point, before I take her into the dealership (shudder). Had a good, local independent tech who had 5 years experienc as a GM Goodwrench 6.2 / 6.5 specialist, but he's moved on to greener pastures.

Thanks in advance for any help rendered.

--Ian

[DChristie]

Ian,

Welcome!

The shut-off solenoid is a deep socket lookin' gizmo monted on top of the IP with a pair of wires coming out of it. Some have a nut on top to put a wrench on, others require an allen wrench.

An easy check is to rest your fingers on it and have some-one turn on the key, you will hear and feel the solenoid click open. If it fails check wires etc.
If it is good then I'd investigate the Pump Mounted Driver next. They will go out, seemingly at the drop of a hat. engine will spin like a top but never fire.
All kinds of info is available in the archives for this. search PMD/FSD. There is even a photo or two of a specialty wrench you can make to remove the PMD yourself.
If you find you need a new one, I'd suggest you not put it back on the pump. Lots of members here have them mounted somewhere cooler. Mine is in the front grill, cool air blowin' on all day long. :D
One fellow even has three or four ready to go at a moments notice, just unplugs one and plugs in another.
John Kennedy sells an extension harness and an aluminum heatsink. These make remote mounting possible. He is listed on the advertisers section. Others sell them too, but I've only dealt with Mr. Kennedy.
I hope this helps and encourages you.
again Welcome.

DChristie

[97SubK2500]

Thanks for the help.

The fuel shutoff solenoid is getting nearly 12V from its input line, and it actuates just fine when battery voltage applied to it directly.

So, it sounds like this is a FSD (PMD) problem.

Any other possibilities that I'm missing?

Any way to confirm that the FSD is working OK without removing it and the hours of labor that involves?

--Ian

[a5150nut]

Any way to confirm that the FSD is working OK without removing it and the hours of labor that involves?

Only way is to substitute with another one.

[tom.mcinerney]

>>Tried cranking it over before re-installing the fuel tank cap - and it turned over & started for a few seconds, but died on its own.

"Start...stalls" is more characteristic of a LP prob than FSD. LPs are known to make good noise when not pumping. Might want do press+output test for LP....though it seems your FSD may be shot.

The Helm manual states 15 seconds is max for starter cranking, then let starter cool down for a minute or two....

[Aryeh Levy]

if you've got a newer model, have a friend crank in drive gear, you wont engage starter
but it will energize lift pump
I did this, and unscrewed the fuel filter black thingy to purge - got bout 6" shot of diesel straight up. That means the lift pump's working. there are other ways to do that, like hotwiring the lift pump and then opening purge to see pressue.

But for pressure readings on fuel lines, where do you take the readings????

[97SubK2500]

Tom and Aryeh,

Thanks for the reminder about checking the lift pump. It's got 11k miles on it, and I got a strong stream through the filter purging process. It sounds "normal", too.

Well, I guess it's time to contact Mr. Kennedy for an FSD remote mount kit...

--Ian

[tom.mcinerney]

Aryeh:
>>But for pressure readings on fuel lines, where do you take the readings????

The fuel filter assy drain -- brass valve near thermo at front engine -- connects to filter base, from port at same head as the line feeding the FuelInjectionPump. If you connect a gage to the output/drain fuel line from the brass valve , you thus read gage pressure at the input to the FIP , which is the LP output pressure you are interested in. You can measure pressure with a tee installed in either of these lines , etc.

Measuring FIP output pressure is expensive and specialized.....we in field diagnose inadequate pressure there when engine with good timing and compression won't start.

[tom.mcinerney]

Ian-
suggest Remarque Sol-D !

[97SubK2500]

Received the FSD & remote mount kit from Mr. Kennedy yesterday, and she was running like normal (GREAT, that is) by dinnertime!

Thanks to all who responded to this newbie's need for help. I saved hundreds of dollars of labor charges, and learned a lot about our truck in the process. Can't beat that with a stick!

--Ian