m816 starting issue

[doghead]

My M819 will start then stall, then start and idle high for a few seconds . I have been using the primer pump to build up pressure, after it stalls, then it starts right back up. I have not found any air leaks yet, but I need to inspect the in-tank pick up tube(they rust through above the fuel level).

I think the stall/odd idle/hard restart, is common of an IP in need of a rebuild.

I decided to try to fix this issue today.

First I replaced the 2 plastic fuel lines for the fuel primer pump. I used 1/4" DOT air line with inserts and new brass ferrules.

I then pulled the emergency fuel shut off valve apart. I think this was my problem all along. I cleaned it all up and replaced the shaft o-ring with 2 new o-rings to fill the space and compress them well). You must be very careful when you pull the valve apart as there are a few little clips that can fall out(after you figure out how to get them out). They "clock" the valve port.

Once this was done, I opened the petcock on the cold start system and used the hand primer pump to bleed the system. This took about 25 strokes. Then I closed the petcock and fired it up.

It now starts instantly and when I shut it of(ignition switch) it shuts off like it should(it used to run on some).

I let it sit a few times for about 5 mins or more, and each time it fired right up with no hesitation and no high idle(like it used to).

Just thought I'd update this post with my issue.

 

[Welder Sam]

I decided to try to fix this issue today.

First I replaced the 2 plastic fuel lines for the fuel primer pump. I used 1/4" DOT air line with inserts and new brass ferrules.

I then pulled the emergency fuel shut off valve apart. I think this was my problem all along. I cleaned it all up and replaced the shaft o-ring with 2 new o-rings to fill the space and compress them well). You must be very careful when you pull the valve apart as there are a few little clips that can fall out(after you figure out how to get them out). They "clock" the valve port.

Once this was done, I opened the petcock on the cold start system and used the hand primer pump to bleed the system. This took about 25 strokes. Then I closed the petcock and fired it up.

It now starts instantly and when I shut it of(ignition switch) it shuts off like it should(it used to run on some).

I let it sit a few times for about 5 mins or more, and each time it fired right up with no hesitation and no high idle(like it used to).

Just thought I'd update this post with my issue.

good deal. im slightly intimidated by the variable speed pump and primer pump. i know i need to rebuild the hand pump and change both fuel filters. but.....

 

[doghead]

The hand pump is easy.

I suggest you pull it out of the truck and do it on a bench. There are 2 small springs and check balls you do not want to loose. I clean them and their seats with carb cleaner and Q-tips.

I had already done that a while back.

I'm not sure I solved my issue, only time will tell for sure. But today it seemed better.

 

[Welder Sam]

Dh, thats just about word for word what ron said too. In warm weather it kicks off good even after sitting for a week or more. In cold weather, when its needed most, i have to bump the starter a couple rounds to, and im guessing here, prime the primer. After that, it hits 120 easy. Dumps fuel on my right boot when i pull the t-handle out though. This is one of those things that if i saw it done once, id be down with. The lack of soldier b to close bleeders or run the pump shys me away too.

 

[doghead]

To prime, you simply leave the petcock open. There is a needle valve as well as the check balls) in the primer. It's a one man operation.

 

[Welder Sam]

Ah-ha! I knew i was misreading something somewhere! Thanks man

 

[doghead]

This is also how you prime the system after a fuel filter change.

 

[Welder Sam]

This is how i took it

 

[doghead]

I'm not sure I solved my issue, only time will tell for sure. But today it seemed better.

The truck has sat for a few days. Today it cranked and fired right up. I seem to have fixed my air leak. I don't know for sure if it was the new lines with new inserts(I did try to put an insert into the old line and it would not fit in the end of the old plastic line. The line was also very hard) Or it may have been the emergency shut-off valve.

 

[m816]

I'll go with the transfer switch fuel lines. They dry out,crack and/or collapse and you start sucking air. That cummins will not run with air in the fuel system. and that pos switch couldn't be in a more inaccesable spot. It will sure up the alcohol intake levels until you fix it

 

[doghead]

It's an M819, only one tank. I was talking about the primer pump lines.

 

[crasheej]

It's an M819, only one tank. I was talking about the primer pump lines.

The pump dose not prime the pump all it dies is pump fuel into the intake. That is used for cold starts.

 

[Jakelc15]

The pump dose not prime the pump all it dies is pump fuel into the intake. That is used for cold starts.

It does prime the fuel. Open valve on intake and pump away. It will suck fuel through the pt pump and filter from the tank.
Put a piece of hose on the end and stick it in a bottle, check for bubbles.