M817: Starting issues, no prime, at wits end!

[coxoncall]

not trying to hijack the thread.
We have a 1989 M817 and I cannot get the primer to pump up to any pressure.
I have pumped it well over 500 times in one sitting and many times in other tries.
It has fresh fuel in the left tank.
The dash tank selector is left.
The drivers side floor selectors is left.
The emergency stop is pushed in all the way.
I filled the large fuel filter under the driver's side fender.
I poured diesel into the injector pump and cleaned out the injector pump filter.
I am ordering a set of fuel filters this week to replace both of them.
We just tried to pull start it with our M35 for about a half mile and nothing but light white smoke out the stack.
The air pressure built up in the system rather fast when pull starting it.
4 brand new batteries as of 2 days ago.

 

[doghead]

Did you open the petcock, when you pumped?

Has your pump ever worked for you?

Have you run it before on the left tank with the valve set as it is now?

Did the truck run normally ever?

 

[coxoncall]

Did you open the petcock, when you pumped?

Yes, on the intake manifold elbow.

Has your pump ever worked for you?

No.

Have you run it before on the left tank with the valve set as it is now?

Yes.

Did the truck run normally ever?

Yes.

 

[doghead]

You may need to remove and clean your primer pump.

It has 2 orings. It also has 2 screws that can be removed (on a workbench over a pan). Under those screws is a small light spring and a steel ball.

Carb and choke cleaner and Q tips work well.

Also, the needle valve must work(move).

Since it never worked for you, I would look closely and determine if it is plumbed correctly too.

 

[doghead]

Is the washer set where it needs to be, for the filter bolt?

 

[coxoncall]

You may need to remove and clean your primer pump.

It has 2 orings. It also has 2 screws that can be removed (on a workbench over a pan). Under those screws is a small light spring and a steel ball.

Carb and choke cleaner and Q tips work well.

Also, the needle valve must work(move).

Since it never worked for you, I would look closely and determine if it is plumbed correctly too.

I did remove it today and noticed scraches midway along the rod.
The orings looked dry and probably should be replaced.
Anyone know the size?
As for the plunger and pin, they push in and out fine. I will remove and take a picture tomorrow and clean it with carb cleaner and take a picture.
I will check all of the lines for tightness.
I notice 3 lines behind the dash. a top, middle, and bottom. The top line is copper, the middle line goes to the elbow on the intake manifold, and the bottom line goes to the injector pump. Does this sound correct.

I am still combing the manuals for part numbers and diagrams.

Thanks you doghead for your quick and concise remarks!

 

[coxoncall]

Is the washer set where it needs to be, for the filter bolt?

I will verify this tonight. At last look I thought it was set.

 

[doghead]

One other concern may be your tank selector valve. They are notorious for leaking air as well.

I found this while searching for o ring sizes. http://www.steelsoldiers.com/showthread.php?104619-M817-Blowing-smoke-but-won-t-start Good reading.


Obviously your primer needs repair first.

I think I recall the orings being 1/2" od and 3/8 id.

 

[73m819]

Is the FLAT WASHER on top of the of the fuel FILTER set IN THE RECESS AND IS FLAT, if NOT the top O-RING will NOT SEAL AND YOU will SUCK AIR.

 

[coxoncall]

Is the FLAT WASHER on top of the of the fuel FILTER set IN THE RECESS AND IS FLAT, if NOT the top O-RING will NOT SEAL AND YOU will SUCK AIR.

It was not. I seated the square washer and tighened the bolt.
I primed the pump 300+ times (lost count after a bit) zero pressure.

Attached are the pictures of the primer pump. I will be getting the orings replaced.

Does anyone know if the scratches on the brass rode are from normal usage?

 

[doghead]

The scratches are OK.

You'll need to remove the primer from the dash, to clean the 2 check balls and their seats.

 

[coxoncall]

The scratches are OK.

You'll need to remove the primer from the dash, to clean the 2 check balls and their seats.

I will pull the back half here shortly. Will i need to replace the seats? Material?

Thanks again for all of you guy's help!

 

[doghead]

No replacement, just clean.

I use a q-tip and carb cleaner.

Remember, the springs are small and light. Do this over a pan, or bowl. Under each(2) screws there is one spring and one ball.

 

[doghead]

How full is your fuel tank?

Have you ever replaced your rubber fuel line that connects to the IP? (frame to IP, 1/2" id)

 

[Monty]

I had the same problem on my 818, truck ran fine for the first year I owned it then I was running it in winter using the ("wonderful pump method") to move some things around. After about five cold starts using the cold starting method on the dash the truck started getting harder and harder to start. I did everything you did, more pumping, changed out the fuel filter, the line from the fuel filter housing to the injection pump, all the lines on the fuel selector next to or under the driver seat, cleaned out the injection pump as described before and it still wouldn't start. I finally got feed up and installed a 12vdc electric pump inline from the fuel filter to the injection pump and the truck fired right up.

I let it run shut it off removed the pump and tried to start it and the same crap, I finally removed the cold start hand pump from the system by plugging were it feeds into the bottom of the injection pump ( I believe it's 1/8th inch npt so I plugged it). After that it started with out any problems and has for over a year. This past summer I drained and cleaned out the coolant system and installed a block heater in it and it always fires right up after being plugged in for 1/2 hour.

Hope this helps

 

[coxoncall]

How full is your fuel tank?

Have you ever replaced your rubber fuel line that connects to the IP? (frame to IP, 1/2" id)

Fuel Tank is 3/4 full of month old fuel.

I will be ordering parts today to replace the fuel lines, rebuild the pump, and suggest the electric fuel pump to the owner.

 

[coxoncall]

Update: Air leaks Everywhere

I ordered the orings, fuel lines (all on the drivers side only), separator filter, and IP filter.

When I went to remove the FWD portion of the primer pump assy (behind the dash) I notice the fuel line and one of the return lines was loose. Being as it is 13°F outside I went ahead and did a pressure test of the tank...**** COLD OUT BTW! All of the fuel lines showed large leaks. When I went to remove one of them is just completely broke off.

We are going to drop the tank, clean it out the best we can, re build the tank selector, replace all the soft lines on the drivers side tank, and rebuild the primer pump. This may take a couple of week due to the weather.

Anyone have a source for the 24 Volt jumper cables?

Thanks again for all of your help.

 

[WillWagner]

No need to change the little screen filter in the pump. It is only there to stop debris from getting into the injectors if there is a pump failure.

 

[coxoncall]

ok heres the update:
Replaced all fuel lines on the drivers side tank and the main line to the Injector Pump.
Replaced the injector pump filter and large fuel filter
rebuilt the primer pump with new orings
cleaned the primer pump seats with carb cleaner

It still will not start. it still just puffs white smoke when cranking. We have not tried to pull start it again.

I have attached a couple of pictures of the emergency stop to verify it is where it is supposed to be.

 

[doghead]

Are you able to prime/pump/bleed the fuel system now?