1992 6.5 crank no start

[DmaxMaverick]

Fuel should only flow to the return when cranking (injection pump turning), but the lift pump should provide pressure any time it is powered. Any air in the system should push out the return line as it's cranking. If it continues to get more air once bled, you have a leak on the suction side of the system (a pressure side leak will leak out fuel), or the fuel level in the tank is too low.

If you had air in the system, then bled it out via the filter bleeder, the injection pump, injector lines, and injectors are still air-locked. Once you confirm fuel flow/pressure, with no air, remove some glow plugs and crank until you get fuel mist from the GP holes. Keep the batteries fully charged and let the starter cool after a few seconds of cranking. It may take several attempts, about 15 seconds cranking, 2 minutes cooling cycles. Longer cranking, less cooling, or discharged batteries make the process longer, and can damage the starter. Removing glow plugs shortens the process significantly.

[arveetek]

You mentioned the glow plugs are working; have you actually verified they are heating up? These diesels WILL NOT START without a healthy glow plug system.

Casey

[atikovi]

You mentioned the glow plugs are working; have you actually verified they are heating up? These diesels WILL NOT START without a healthy glow plug system.

Casey

Replaced them 8 years ago and have only driven it maybe 20 miles since. It was 70 degrees yesterday and not even a sign of wanting to start after 5 or 6 attempts.

[Yukon6.2]

Replaced them 8 years ago and have only driven it maybe 20 miles since. It was 70 degrees yesterday and not even a sign of wanting to start after 5 or 6 attempts.

As i wasted a bunch of time yesterday "assuming" my boiler system was ready to start seeing it was working fine when i shut it off last spring.Every fall it's a simple procedure for the first fire and many burns to bring my system up to temp.Not yesterday.It was air-locked and by me assuming it was fine i put the system in jeopardy.If the final safety had not shut down the fan it could have turned into a steam explosion if it was left unattended.

Verify your glow plug system

What you did 8 years ago means nothing today.

[arveetek]

Verify your glow plug system

What you did 8 years ago means nothing today.

Agreed. Just because it hasn't been driven much doesn't mean there's nothing wrong with the glow plugs. These older IDI GM diesels won't even start in 80 degree weather without some glow assistance.

Plugging in the block heater to warm the engine will help a bunch as well.

Casey

[atikovi]

Agreed. Just because it hasn't been driven much doesn't mean there's nothing wrong with the glow plugs. These older IDI GM diesels won't even start in 80 degree weather without some glow assistance.

Plugging in the block heater to warm the engine will help a bunch as well.

Casey

So it wouldn't even SEEM to want to start after all that cranking? Hard to imagine ALL 8 new plugs wouldn't work.

[JohnC]

If it's getting fuel but no heat it would blow white "smoke" out the tail pipe. Crack the lines on a couple of injectors and see if they weep fuel when you crank it over.

[Yukon6.2]

It doesn't matter if the glow plugs are new if they are not getting power
It takes very little time to verify.
If the truck doesn't start you need to diagnose why.
That means checking the things that would make it run and finding the one or ones that are not allowing the engine to start.
Guessing and assuming will waste your time.
Plus it wastes the advice that people are giving you to try and help you.

[arveetek]

So it wouldn't even SEEM to want to start after all that cranking?

Nope!! I had an 82 6.2L that wouldn't start one day after a massive glow plug failure. I don't remember what happened, but all 8 plugs burned out (probably due to an error that left them on too long). It was 82 degrees, and it wouldn't even hit a lick.

These old, mechanical IDI diesels need just three things to start: fuel, air, and heat.

As long as the air cleaner and intake manifold are open and clean, the engine will get air.

If the fuel system gets air in it, it can be difficult to get out. However, following DmaxMaverick's advice above to get air out will be the best thing to do: remove all 8 glow plugs, and spin the engine over until you get fuel mist coming out. Shouldn't take all that long.

Once you have fuel mist, all you have left is heat. The engine will need to spin pretty fast in order to create enough heat from compression. To assist with cold starts, the glow plugs heat up the air inside the precombustion chamber. Since you have the glow plugs out from the previous step, now is a good time to check them. Once you verify the plugs are good, and that you actually have voltage to the plugs during the glow cycle, the engine WILL start once the plugs are installed (assuming that no one has messed with the injection pump timing at some point).

I rebuilt my 6.5L about 2 years ago. After reinstalling the engine (with new injectors), I followed the procedure above to bleed the system. It worked like a champ, and the engine started almost immediately once I installed the glow plugs. Here's a video of me starting the engine for the very first time; at the point the video starts, I had already spun the engine over without glow plugs until I had fuel mist coming out; I then installed the glow plugs, and then hit the 'record' button on my phone:

https://www.youtube.com/watch?v=mPMMtMAyQmo

As you can see, it took very little cranking until she was running.

If you don't have fuel mist when cranking the engine with the glow plugs removed, then we can stop and take a step back to see what is wrong with the fuel delivery system.

I hope this helps!

Casey

[JohnC]

One winter day, many years ago, I needed to move our '93 6.5. It had been sitting for several weeks, and when I went to start it it cranked over in that manner where you wonder if it'll make it over the next compression stroke. No need to wonder, though, as it fired off after no more than 4 compression strokes. Cranking RPM in my estimation, was no more than two cylinders per second, or 30 RPM, if my math is correct.

I'm pretty sure the glow plugs were working...

[atikovi]

remove all 8 glow plugs, and spin the engine over until you get fuel mist coming out.

I'm working by myself. How do you do that? I mean, I can't watch the plug holes AND crank at the same time. And how long cranking before mist comes out?

[DmaxMaverick]

Place a paper towel along the bank at the GP holes. Crank for 10-15 seconds. Check the paper towel. Repeat as necessary. You don't need to see fuel at all the cylinders, only a couple. It can take many cycles, like 10-20, but may be as few as 2 or 3. It depends on how much air is in the system, the overall health of the IP and injectors, and/or cranking speed. Keep the batteries charged.

[arveetek]

I'm working by myself. How do you do that? I mean, I can't watch the plug holes AND crank at the same time. And how long cranking before mist comes out?

It's very obvious when you get fuel mist; it fills the engine bay with what looks like 'smoke'. I did it by myself on mine, and it was very obvious. I think it only took 2 cranking cycles of about 20 seconds before I had a lot of fuel mist.

Casey

[JohnC]

Just stand by the driver's door and stick you hand in through the window and turn the key.

[Robyn]

With the plugs out the starter can really whip the engine over....Nowhere near the drag as when it's bucking compression....
All the times I have done this with dry fuel system (Injectors, HP lines and a rebuilt IP) and just fuel up to the IP from the filter and the lift pump running full on...The time to have fuel fog out from under the hood was 20-30 seconds of cranking....
Replace the plugs and go for a start....Glow and let it rip......Generally the engine will start and stay running....Maybe a little rough off and on for a short time until it settles down and smooths out to a nice idle.....

If no fuel out the glow plug holes after a couple sessions....PROBLEMS.....Fuel shutoff not working.....
Make sure of 12V to the power plug on the IP....LARGE PINK WIRE ON IP.

Make sure you have fuel delivery to the IP when you are cranking.....
Jumping the LIFT PUMP relay will run the lift pump....

The lift pump comes on during the "POST" for a short time....

[atikovi]

Got back to the truck to try again.

Hotwired the lift pump and opened the bleeder on the filter. Got a good bit of bubbles and air for 5 seconds, then a solid stream.

Closed the bleeder on the pump and went to the valve up front. Opened that and got more fuel coming out that rubber hose. Closed the valve and attached a pressure gauge. Getting a good 8 psi with the valve open.

Still no start.

Pulled out 3 glow plugs on the drivers side. With lift pump working I cranked three times, maybe 10 seconds each time. No mist coming out. Dry holes.

Would a bad shutoff solenoid cause this? I hear just a faint click when energizing the terminal and get a bunch of little sparks as well when touching a wire to it. Kind of like when you test a bad window motor with an internal short.

If so do I have to remove the intake cover to access it. There isn't much room to get to it in place.

[JohnC]

Keep cranking. Crank at full throttle. The amount of fuel pumped per compression stroke is relatively small compared to the volume of the fuel lines.

Keep in mind that with 5 glow plugs in, the engine may start... You could loosen the B nuts on the remaining injectors to prevent starting.

[atikovi]

Keep in mind that with 5 glow plugs in, the engine may start...

If by some miracle that occurs, what's the problem there?

[Robyn]

No worries.
If it tries to run it won't hurt it...Shut down and get the plugs back in...

The IP SHOULD make a pretty decent click when you connect the Big pink wire with the ignition on....
A faint click may well indicate a failed shut off solenoid.....

Replacing it is NOT HARD...Just tedious....REMOVE the top cap on the IP.
The solenoid is under the cap.....

You need to read the R&R procedure well....If you replace the solenoid and do not get it in correctly it will allow the engine to start....BUT the throttle will go full on and no way to shut it off....
Get hold of the manual on the DB2 and read the part on replacing the solenoid......

Try a few more spins of the engine to see if she will fuel up before you go after the solenoid...

[JohnC]

what's the problem there?

It depends on whether you're expecting it and shut it off or you're not expecting it and freeze (with your foot on the throttle and fuel spraying out of three holes.) Just a heads up...