M923a2 starting issue update.

[Ttallent13]

I think I’m loosing prime. If I prime the motor at the lifting pump the truck fires right up. I tried cracking the bleed screw past the lifters and I get air then fuel, But If I let the truck sit a few hours then it goes back to not starting. So I’m thinking it’s sucking air and bleeding down. I ordered the fuel line going from the main fuel filter. I also ordered the spin on filter base to remove that huge canister filter. Anyone have a link or know where I can get the fuel line that goes from the frame to the filter.

thanks
Tommy

 

[98G]

NAPA can build you a fuel line with the appropriate fittings on each end.

 

[Jbulach]

I would throw a new overflow check valve on the pump. Also, check to make sure your fuel tank dip tube on the return line is still intact.

 

[Superthermal]

I would throw a new overflow check valve on the pump. Also, check to make sure your fuel tank dip tube on the return line is still intact.

My suction tube was quite pitted. This is a common issue for your rig sucking air. In my case it didn't have any holes, but I did sheath it with some fuel line and put a hose clamp at the top (not shown) to make sure if it ever does pop a hole, that it sucks from the bottom or near the bottom of the tube just the same. Did this just in case for the long haul since new tubes were not in the budget right now for me. I believe the fuel hose was 1/2" ID.

 

[Wreckclues]

My suction tube was quite pitted. This is a common issue for your rig sucki g air. In my case it didn't have any holes, but I did sheath it just in case for the long haul.View attachment 894032

Is this the pickup tube in the tank? Had the same problem in my M813. Replaced it with a copper one.

 

[Wreckclues]

NAPA can build you a fuel line with the appropriate fittings on each end.

Didn't have any luck with NAPA on my M813 fuel lines, used OMNI Services instead. Think they have locations in Virginia.

 

[Superthermal]

Yes that was my pick up tube on the stock 78 gallon tank of my M813. My return line only had a fitting in the top of the tank and no tube at all going down into the tank. From reasearch, I understand that on the return, it is best to have a return drop tube so the fuel returns below the level of the fuel in the tank and is not aerated as it is "sprayed" back into the tank. Since I will hopefully be adding two other tanks to my rig on the passenger side with "dump" lines into this "running" tank I will deal with that later.
More info on how that multi tank design I am imagining will work here:

WMO users in Ohio?

I just looked it up you're right most dryers spin at a maximum of 2000 RPMs but some commercial ones spin up to 3900 according to a quick Google search

www.steelsoldiers.com

I decided what was there was fine for now and I would add something better down the road for getting fuel into the tank in the best way possible. You can follow my progress as I go on my own rig build here:

Superthermal's M813 Build, THE BOT

Had been looking for some time for an M813 with winch. Not much luck and was always behind another buyer it seemed. Finally found one in decent shape and an excellent price but on the other side of the US from me. The rig was located near Detroit. I know that is a long ways away but I bought...

www.steelsoldiers.com

 

[Jbulach]

Regardless of why down tubes were designed on these return lines, if you still have yours and it doesn’t leak that is one less place to introduce air, if your check valves aren’t doing their job perfectly while not running.

 

[Valley Rock]

Previous quote from this thread: "From reasearch, I understand that on the return, it is best to have a return drop tube so the fuel returns below the level of the fuel in the tank and is not aerated as it is "sprayed" back into the tank."

I also have read this idea before and it is not something personally I would do, I shall share with you why, and you cant reach your own conclusion .

I have never "personally" had a problem with aerated fuel FROM THE TANK, in these trucks, in fact actually due to only due to a faulty return valve at the pump OR from leaky fuel lines .

That being said, these trucks tend to set around for years, maybe while you own them or maybe before you owned it .

How many people have removed their tank and all of their fuel lines and filter housings and cleaned up everything like an operating room in a hospital ?
Answer: no one .

There is always ALWAYS, some junk of some sort in the bottom of the tank, where it will typically set and stay in its home safely for years just below the reach of the pickup tube, until an extended return tube is put to the bottom of the tank to blow it around like a fan in an aquarium for the suction tube to do its job and suck it on up .

If you actually believe that your engine is running poorly due to aerated fuel, then add an inline elec. pusher pump ($25) back near or in the tank .
This Will do three things, it will keep your fuel compressed in your lines which is favorable over the fuel being pulled from the injection pump, it will give the upper pump a break or do the job for it should it quit, and it will show you any leaks in the fuel delivery line since it will be lightly pressurized .

I don't know why these trucks dont have an in tank pump like the Duece and a halfs, if they do then mine doesnt work, it would stop 90% of the fuel problems with these trucks if they had one (or two)

I'm just a guy who figures things out as I go along, the above is just my opinion, there may be others like it, similar, or completely opposite, but that one is mine at this moment in time .

~ Peace & bacon grease ~

 

[WillWagner]

No need to return fuel to the bottom of the tank on these. There is almost no return. The injectors dump to the pressure filter inlet and the amt of fuel coming from the overflow valve is minimal. When it returns it is not under pressure, just a bit of flow.

The only way to see what is going on is to install a clear looped line from the pump to the pressure filter and some gauges, restriction from the tank and in/out of the pressure filter. Otherwise, you are just guessing.

 

[WillWagner]

I can drawer a picture if you like, but, the engine needs to be fired off and ran a bit after the test stuff is installed in order to fully get it right the first time and not unleash the parts cannon on it.

 

[WillWagner]

PDF to print, JPEG just to look at.