Warm engine stalling while driving

[General Mcgregor]

Ok Here's the problem in a nutshell...
My truck starts up fine in the cold, In NH it's been at or below +20 lately but my m35a2 fires right up every time with no need for the manifold heater.
I run her at about 1500-1800rpm until she warms up
Take her out on the road and she runs great!!! ... ...... ...........Until the temp reaches at or above the centerline...
The engine seems to loose power and die...then start running again...then die while I'm driving in gear
If I pump the throttle it seems to help, a little
It actually stalled dead on me a couple of times the other day
It seems like it's not getting enough fuel or maybe there are bubbles in the lines etc.
Oddly enough I can run it up in my driveway when I get home and I can't get it to do it, I.E. Only does it under load in gear and when warm.
When I look at my clear fuel lines it looks like there may be air bubbles leading to the injectors, But there is DEFINATELY air bubbles coming from that canister on top of the engine beside the forward valve cover
There are no visible signs of fuel leaks like dripping or anything
I bled the fuel filters and line coming up to them but I don't know how to bleed the rest
HELP PLEASE! Thank you in advance guys!

 

[wb1895]

I would change all three fuel filters, and check and tighten ALL of your fuel connections. I have to check and tighten most of my fuel connections every hundred or so hours, or I will get some slow fuel drips.

If you have bubbles in your fuel lines then you have a loose connection, or a small hole in the line.

 

[Floridianson]

Let work backwards. When all is right in the world the intake pump will pump all air out of the system and we just have to crack the bleeder at the fuel filters and you can even let it run a little bit after the air comes out. It will not hurt the pump but clear all the way back to the tank.
This is why some trucks have problems, all the fuel line system including the return must run clear and correct.

The forward canister you got me. The twin fuel canisters are driver side and clost to firewall. Here is where we bleed and also test for all the correct pressures for just intank pump alone. Then when running at idle and at full rpm. The truck will run fine if you lost your intank pump for some reason. Here is the trick if you do not change the filters or open the system and all is right in the world the truck will allways start and run fine. Open the dilivery system by hole made in the line or we open the filters then we must have working intank pump to bleed system the way is was built.

I am going to take a little break as can't type to long. Some outher operator should be with you soon to help and if not I will check back in and try to add more.
Ok back at you Operator 53 is on line how can I help you now.

The motor to run at full rated numbers the intank must produce 5 to seven but some run 4 lbs. From there the ip fuel pump must produce around 35 at idle and 75 full rpm.
You must find out if all lines are running clear and free and find the air leak if there is one bottom line. If your in take is pump is pumping not just makeing noise then the leak should show it's self when you just turn on the pump.
There has been people who have found bad hose in fuel tank and had to replace to correct.

Im tired again so someone will be right with you. Bye

 

[General Mcgregor]

I think the air bubbles are coming from the flame heater (the canister) at least I think thats what it is. There seems to be fuel in that line but it keeps drawing air bubbles from there.

 

[General Mcgregor]

I've been running Diesel winter additive for the past few months so I don't think it's a gelling problem.

 

[mhassett]

Change primary fuel filter.
Mine did that in warm weather.
MHassett

 

[Wildchild467]

i have some bubbles in mine once and a while. its been a while since i have looked close to see them, but if the return line from the injectors have bubbles, could be a worn injector seeping a little bit of air past the needle of the injector. Im not a diesel mechanic, but i have a good understanding of some things, but again not a professional. Maybe somebody can chime in if i am wrong. My truck didnt always run consistant and I found after i put the winter front cover on it helped a lot by keeping the engine temperature up even though it was at 180 on the gauge. But in the process of me looking for possible air leaks in the fuel system, i checked everything. First i started at the tank and looked at the pump and hose inside the tank. I also found the pump was not at the proper depth per the TM... it was 2 inches higher. so i corrected that and replaced the hose in the tank (pump to top of tank) just because it was not that expensive and i wouldnt have to worry about it again. Maybe if your hose is leaking (insert joke here) air could be getting in your lines there. Just read the snot out of the TMs and they explain a lot, just have to find all the information which sometimes can take a little bit, but its in there. Dont forget to check the line that goes under the radiator to make sure it is not kinked.

 

[wb1895]

You could also have trash in the fuel tank. There is a small screen on the bottom of the in-tank fuel pump that could be getting clogged as you drive causing a reduced amount of fuel delivery.

 

[General Mcgregor]

My truck didnt always run consistant and I found after i put the winter front cover on it helped a lot by keeping the engine temperature up even though it was at 180 on the gauge.QUOTE]
So even though the temp on the guage was normal the cold air made it run like crap? Was it behaving alot like I described? I had never had any problems like this until the cold set in.

 

[General Mcgregor]

C'mon boys is it your bed time already???

 

[General Mcgregor]

Problem solved!

She was getting too cold as I drove her! This is my 'Poor man's cold weather front' works great!!!

 

[wb1895]

This is the first year that I put the winter cover on the front of my deuce. It made a huge difference in performance from last year. I cant remember who I got my winter from from here on SS, but I believe that it was only $30.00 new and with all the hardware. It is worth its weight in canvas

 

[Wildchild467]

My truck didnt always run consistant and I found after i put the winter front cover on it helped a lot by keeping the engine temperature up even though it was at 180 on the gauge.QUOTE]
So even though the temp on the guage was normal the cold air made it run like crap? Was it behaving alot like I described? I had never had any problems like this until the cold set in.

Well my truck didnt run completely like crap, just sometimes it would not idle as good, could just feel like its sluggish. the gauge on the dash works fine, the temperature gets up to 180, but it seems to like having the front cover on it and i like running it around 200 degrees.... i think it promotes complete combustion and i do notice that it feels like it runs a little better (i can tell on the hills). When i hit a hill, i dont have to have it floored as much to get the power. Its not a HUGE difference, but enough for me to think im doing something right.

 

[Wildchild467]

She was getting too cold as I drove her! This is my 'Poor man's cold weather front' works great!!!

Even have the bridge numbers on it! NICE!

 

[Kalashnikov]

I would say the flame heater is allowing air into the system. Cap off the lines or connect them back to the injectors and seem if that cures it.

Loosen the bleeder screw on the secondary and final filters and fuel should spray, not dribble, out.

Loosen a connection to one of the injectors and crank the engine and fuel should squirt out.

Turn the power switch on and listen for the return fuel splashing in the tank.

I had a similar problem where the truck would cut out in 4th and want to die. Turned out my return lines were clogged.

An after thought is that my flame heater leaked badly but the truck always ran fine, just was hard to start. I'd check out the pressure at the injectors and for returning fuel because it sounds like it's starving for fuel. Blow out the lines with compressed air then run a few gallons of gas and diesel cleen to help clean the lines/fuel system.

 

[General Mcgregor]

Even have the bridge numbers on it! NICE!

Of course!!

 

[General Mcgregor]

Still happening

She was getting too cold as I drove her! This is my 'Poor man's cold weather front' works great!!!

Disregard started doing it again today. Thought everything was fine and dandy after I put the cover on. I am going to start by replacing my fuel filters. (they should probably be done anyway) Next I am going to check all of my fuel line fittings all the way back to the tank. I'll try running some gasoline through it to clean her out a bit too. I will also check the pressure on the injectors and at the secondaries. Whats the best way to go about that btw?

p.s. Could there be water in my system? I don't completely trust the gasket around my intank pump and it's been snow covered recently.

 

[Wildchild467]

I just thought of this, dont know why i didnt think of it before. have you adjusted the valves? I checked mine and a couple were tight. If you dont have enough valve clearance, the engine will get hotter under load, valves get tighter and you could be losing compression causing it to quit. diesels need 2 things to run. fuel and compression. it seems you are getting enough fuel to make it run, but what about the compression? I dont know why, but i have a good feeling about this one..... check the valves

 

[General Mcgregor]

I just thought of this, dont know why i didnt think of it before. have you adjusted the valves? I checked mine and a couple were tight. If you dont have enough valve clearance, the engine will get hotter under load, valves get tighter and you could be losing compression causing it to quit. diesels need 2 things to run. fuel and compression. it seems you are getting enough fuel to make it run, but what about the compression? I dont know why, but i have a good feeling about this one..... check the valves

Can they be adjusted easially? Just pop off the valve covers right? And I need to tighten them not loosen right?

 

[Wildchild467]

yes, pop off the valve covers and check the valve lash with a cold engine. All the information is in the TM's. I dont know what you need to do with the valves exactly because you should check the valve lash before you do anything so you have a good starting point. If you have a "tight valve" that means the valve lash (clearance) is too little. The TMs have all the information to do the job.... its not bad to do.