M35a2 stalling when hot?

[RAYZER]

Edited my post.
A fuel pressure test would be a good place to start.

 

[andy3]

15-20 seconds to start and still have to play with pedal? It is starved for fuel. Is the truck making oil?

 

[RAYZER]

http://www.jatonkam35s.com/DeuceTechnicalManuals/LD-465Maint.Man.TM9-2815-210-34-1.pdf
This tm has some test procedures on the fuel system, there are other tm's that deal with the fuel system as well.

 

[JP871Racing]

Definelty will do a pressure test too, good thing I just bought a new snap on tester. Do you mean is the truck building oil pressure? Because it is when I go to start it it's at 30psi, and when it's at idle it's at 45-55psi, and that has a brand new gauge and sending unit also. They didn't work when I bought the truck.

 

[73m819]

In my opinion, this doesn't sound like a valve adjustment issue.
I think your dealing with a fuel system problem.
I would look at injectors and injection pump, a compression test wouldn't be a bad idea either.
Maybe start with a fuel pressure test.

Also the starting issue sounds like you are sucking air/loosing prim, the stall could be caused by a fitting or something a bit loose, that opens up when hot, allowing you to suck air.

 

[andy3]

Sorry, I was asking if the oil level rises after driving the truck. If I can quote Clinto there are 5 places that fuel can enter the oil on the truck. 3 of them are in the area of the IP & HH. If that is happening you would have low fuel pressure and be at risk of washdown/wear in the engine from thinned oil.

 

[JP871Racing]

That's something else I will do today, I'm gonna check all my fittings to see if any are loose. Plus check all my rubber hoses near the engine, one thing i haven't scrutinized yet. At least I know everything on the fuel tank and fuel pump are tight, so no worries there, but as far as the oil level, I haven't noticed any significant changes on the level, but what I can do is take a scribe or scratch awl and make a mark where it is now, run it for a few days then check it again when it's cold, if there is any difference, then the injection pump has to be the cuprite.

 

[RAYZER]

There is a fuel pump on the injection pump itself that can be pressure tested.

 

[JP871Racing]

I did see that in the tm plus I found the specs on what the pressures should be, correct me if I'm wrong but this is what I found:

Delivery valve opening pressure . . . . . . . . . . . . . . . . . . . .250-400 psi
O v e r f l o w p r e s s u r e . . . . . . . . . . . . . . . . . . . . 5 psi max.
Fuel pressures, minimum (after final filter):
700 RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 psi min.
2600 RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 psi min.
Pressure regulator valve setting (all fuels) . . . . . . . . . . . . . . . . . . . . . . . . .20-21 psi

 

[patracy]

Those numbers are correct. I actually added a mech oil pressure gauge to my fuel filter housing on one truck after wiping out a HH. (Starved it for fuel) I never took it back off either because oil pressure gauges are cheap, and it's a nice quick indicator as to what's going on with the fuel system.

 

[JP871Racing]

That is such a great idea! I actually have an old mech gauge laying on one of my shelfs somewhere and I know it works. I'll have to plumb that in to the filter housing, because your right, that is the last thing I need to happened is fry a HH. It will give me a piece of mind when driving long distance. It's kinda off the subject but after doing more reading on certain posts on here, it seems advisable to get a pyro gauge for these trucks. I'm gonna start saving $ to buy a good kit from ISSPRO.

 

[RAYZER]

If I'm not mistaken, the 800 series 5ton with the 250 uses a mechanical oil pressure gauge that can be used for that purpose.

 

[JP871Racing]

I'll have to check that out, see if I can't track one down. It would be nice to keep all the same gauge.

 

[Floridianson]

So who is going to break the bad news to JP871 if the Head is bad?

 

[RAYZER]

So who is going to break the bad news to JP871 if the Head is bad?

I think that might be you James since you have one to sell him!

 

[JP871Racing]

I'm not gonna admit defeat yet, I'm gonna start checking pressures and tear into the pump a little

 

[steelandcanvas]

I actually added a mech oil pressure gauge to my fuel filter housing on one truck after wiping out a HH. (Starved it for fuel) I never took it back off either because oil pressure gauges are cheap, and it's a nice quick indicator as to what's going on with the fuel system.

I have done the same thing to keep an eye on fuel system pressures. I used an 1.5" back mount gauge mounted to a tee. I removed the bleeder screw and placed it on top of the tee to retain the bleeding feature. The gauge has a 0-100 psi scale.

 

[JP871Racing]

I know I should have mentioned this way earlier in the thread so please don't bash me because I forgot, would running clean used motor oil have anything to do with my problem? Maybe the HH is acting like it's starving for fuel because the oil is to thick to run through it? Just still trying to eliminate having to dish out for a new hh

 

[RAYZER]

I know I should have mentioned this way earlier in the thread so please don't bash me because I forgot, would running clean used motor oil have anything to do with my problem? Maybe the HH is acting like it's starving for fuel because the oil is to thick to run through it? Just still trying to eliminate having to dish out for a new hh

Is your fdc bypassed?
Mine is and I've run filtered wmo of all different consistencies through mine without any Ill effect.
But it's best to run wmo mixed with gas or diesel 50/50, imo.

 

[JP871Racing]

The fdc isn't bypassed, it's all there and hooked up. I have it currently 5% diesel and 95% oil at all different consistencies