wondering if im bleeding the fuel system correctly M1151A1

[duanejacques]

so i picked up a m1151a1 slant back at govplanet and it seems complete after my initial inspection. i have changed the oil and all other fluids seem clean. the spedometer gauge panel with the gauges was missing but the tech who removed it left the wiring in good shape. still has the plugs and no wires mangled. i had figured that i would bleed the fuel by the purge line. but no fuel after cranking it . with a small amount of clean fuel sprayed into the intake it didnt seem to ever come alive. my question is with the gauge panel removed is there something keeping it from firing over? there was a decent amount of left over fuel in the tank but i had added 5 gallons of fresh fuel. i was tpld by a freind who owns 5 of these to open the fuel drain valve near the naster cylinder and crank a bit until fuel comes out then close the valve. but i havent seen any fuel yet. i would appriciate any advice. thanks

 

[Coug]

If there is fuel in the tank, but none getting to the filter, either the check valves in the fuel line just in front of the tank are plugged, or the fuel pump is failed.
It could possibly also be an air leak somewhere in the system before the fuel pump, so check over the fuel lines and make sure everything is properly attached and tightened.
Potentially the fuel pickup filter is also clogged, or broken off inside the tank. It is probably a good idea for you to at least pull the cover on the top of the tank and take a look inside to see what the inside of the tank and the fuel pickup look like.

The gauge panel just shows you gauge sender readings, it doesn't have anything to do with the engine starting or running.

Diesel engines aren't like gasoline. You can't just spray fuel into the intake and expect anything to happen. Diesel engines rely on the fuel being sprayed through the injector nozzle under extremely high pressure, atomizing the fuel at the correct time when the cylinder compression has heated up the air enough for it to ignite.
Spraying any type of starting fluid into the intake is also a bad idea, as the glow plugs will cause it to ignite early, potentially causing damage to the cylinder heads and pistons/rods. Some engines it's safe to do it, this type is not.

 

[TOBASH]

1: drain the old fuel from the tank. It is not a good idea to try to use it.

2: fuel lines have check valves that get clogged. You need to remove them.The sock at the end of the fuel intake in the tank gets fouled and blocked… check and/or replace it.

3: with check valves removes and fuel purged, see if you can blow air into the tank from the hose that enters the fuel lifter pump.

4: loosen fuel input to the injection pump at the fuel filter and now see if fuel flows while cranking.

5: this is NOT a gasoline engine. You can’t spray diesel into the intake to initiate ignition. NEVER USE STARTER FLUID UNLESS YOU WANT TO CRACK THE ENGINE. NOT EVEN A LITTLE!

This topic is discussed repeatedly. Technical manuals are provided for free on the forum. Search engine will also turn up many answers here.

Good luck and welcome!

oh…. Hey new guy…

EDIT-below, frauhansen recommends replacing the fuel lift pump… I recommend first making sure the fuel hoses themselves are patent.

You will need to read up in fuel pump replacement to keep from screwing up the easily breakable pushrod. That means you will need to learn to use the TM (technical manuals) and the Search function BEFORE attempting this potentially problematic repair if and when the time comes.

My way you start at the foundation and work up. Frauhansens way has you starting somewhere in the middle. Maybe he’s right. Maybe I’m right. Good luck!

 

[Mogman]

Welcome to the SS forums!

 

[frauhansen]

I recently had my painful story with the diesel.
I would therefore suggest a slightly different approach.

Go the way of the diesel And continue from the tank.
Unscrew the outlet of the lift pump and see if it delivers at all.
If nothing comes out of there, the lift pump may already be bad.

Many people say... pressurize the tank, then this should come out of the inlet of the lift pump. This has not worked for me.
What did work was using a vacuum brake bleeder to pull the diesel out of the lift pump inlet. You can then see whether the lines from the tank to the pump are clear.
You can also, for example, replace the mechanical lift pump temporarily with an electric one and simply draw the diesel from a bucket. Then you can see if everything behind the lift pump is working.

You can also fill the inlet of the original mechanical lift pump from the bucket. Then you know if the pump is working.

You can then take the tank down and check the valves after all this if that will be necessary.

My personal guess... Lift pump broken.

 

[DREDnot]

Fuel Check valves that can be removed

 

[Mogman]

Fuel Check valves that can be removed

View attachment 909656

Should be removed, you will need some 3/8 and some 5/16 line

 

[TOBASH]

I have not seen any follow up replies from the OP.

He has not logged into the forum since midnight last night.

 

[duanejacques]

Welcome to the SS forums!

Thank you very much

 

[duanejacques]

So I have not had any time to physically spend on it but I like the ideas. I plan to drain the tank, then maybe pull it down and replace the lines and inspect the internal pick up. I guess then try the home depot homemade tool to push some fuel forward to the pump. Once I get it there it should be getting pumped up to the filter if the pump is good. I recently ordered the priming valve for the driver side line (it currently has a bolt in it). I found new fuel filters at Royal Equipment in vegas. I really appreciate the help

 

[TOBASH]

So I have not had any time to physically spend on it but I like the ideas. I plan to drain the tank, then maybe pull it down and replace the lines and inspect the internal pick up. I guess then try the home depot homemade tool to push some fuel forward to the pump. Once I get it there it should be getting pumped up to the filter if the pump is good. I recently ordered the priming valve for the driver side line (it currently has a bolt in it). I found new fuel filters at Royal Equipment in vegas. I really appreciate the help

Replace the brass filter sock in the tank. It is also a source of merriment.

 

[duanejacques]

ok. so sorry for the late reply my son just had emergency surgury and it relly scared us but after the whole 2 weeks of panic it looks as if its going well now. So I have read and finaly worked out the bugs on this M1151A1. Here is the results and thanks to all it has been running WAY better than I had dreamed. It turns out that yes I needed to relace the bolt in the bleed hose that was jammed into it VS the spring loaded bleed valve. I had then bought and assembled the YouTube style hose cleaner device to add pressure to the fuel system and maintained 25psi. Once I had fuel moving to the pump I operated the bleed valve on the bottom of the filter hose. Once there I cracked loose the screw and watched the bubbles until solid fuel came out. Then loosened the fitting on the IP. Also a few of the rear injectors. It started like new. I am so proud of how it runs. Originally I had to fill every fluid in the whole truck. I mean everything i am not sure why they had everything drained but it saved me the labor of doing it anyway. It drives great and I hope to add pictures along the way. I also have a 2008 LMTV and a M1152A1