stalling out--help needed

Discuss fixes, upgrades and modifications to your M37

Moderators: Cal_Gary, T. Highway, Monkey Man, robi

Sal
SFC
SFC
Posts: 516
Joined: Sat Jun 21, 2008 4:22 pm
Location: N.Y.

Re: stalling out--help needed

Post by Sal »

Jeff.
I'm a little confused. In your first post you said when it stalls it acts like its starving for fuel, then you say it acts like it flooded. Since you have a electric fuel pump on her do you know what fuel pressure you have ? Do you have a pressure gauge near the carb. You should be getting any where from 4.5 to 5 psi . Any more then 5 you could be flooding it and if its too low you will be starving it .... Just my .02

Sal
:mrgreen:
1954 M37 WO/W
1969 M101A1
1967 M416
Caldwelljj0
PVT
PVT
Posts: 40
Joined: Sat Oct 20, 2007 4:17 pm
Location: Chesterfield, VA

Re: stalling out--help needed

Post by Caldwelljj0 »

Sal,

I thought it might have flooded earlier because it quits and then won't restart until it rests for a half hour or so. Also thoughts it might be vapor lock, but I am thinking I was wrong on that original diagnosis after working on it some more. Now, I am leaning toward more of a fuel starvation issue because the clear fuel filter has almost no fuel in it when the truck quits.

I have an electric fuel pump on it, but it says it is a .5 psi to 4 psi pump. Should I replace the fuel pump with a higher psi, assuming the fuel pump is not pushing enough fuel at this point to keep her running?
Jeff Caldwell
1962 M37
Sal
SFC
SFC
Posts: 516
Joined: Sat Jun 21, 2008 4:22 pm
Location: N.Y.

Re: stalling out--help needed

Post by Sal »

Before you replace anything I would install a pressure gauge before the carb. and after the filter, then you will be able to see if your fuel starving the motor when it stalls out on you.

Sal
:mrgreen:
1954 M37 WO/W
1969 M101A1
1967 M416
WarrenD
SSGT
SSGT
Posts: 470
Joined: Mon Dec 14, 2009 10:55 am
Location: CT
Contact:

Re: stalling out--help needed

Post by WarrenD »

Do you have the original pick up on the fuel line in the tank? The ethanol killed my first one and the NOS replacement. It would partially clog but if left to sit, would unclog enough to run fine again for a while. I took it off in favor of in-line filters I can monitor better. Could also be the fuel pump failing after it gets warm, it is an electric motor.
MarkPick
CPL
CPL
Posts: 121
Joined: Sat Jun 09, 2012 2:36 pm
Location: Cincinnati OH

Re: stalling out--help needed

Post by MarkPick »

There are a lot of things going on at once. I have had a similar problems here is what I found along the way.

My engine used to stall when it got warm, about 10 to 15 minutes running. Went through a whole list of things and finally came down to a compression test. Results was low compression in all cylinders.

A little while later it started again, ( I put in a different motor) this time my in tank fuel screen had came off and the previous owner had used some type of silicone and the pick up tube would suck it up and "hold" it until I blew back through the fuel line. Took the tank cover off and found the problem.

The only way to trouble shoot these things is to pick a component and work through it. Goes without saying that you need Fuel,air and an ignition source all happening at the right time.

I would let it run for a bit and warm up and then do a compression test.
You have checked and you have spark
You have fuel flow, just done know if it is consistent. You could pull the line off and run it into a 5 gallon can and watch and see what happens. Standard safety practices should be observed. If you noticed anything odd, uneven flow, might want to clear the lines.

Again, I have found it helpful to only chase one gremlin at a time, until you catch the little sucker! Just some issues I have ran into. Hope it helps.

Mark
USAF Retired
Desert Storm
Iraqi Freedom
Caldwelljj0
PVT
PVT
Posts: 40
Joined: Sat Oct 20, 2007 4:17 pm
Location: Chesterfield, VA

Re: stalling out--help needed

Post by Caldwelljj0 »

Well gents, I think I finally fixed it. Put a new fuel pump on this morning and it has not stalled out all day. I would say that was the culprit. Thanks everyone for all of the advice.
Jeff Caldwell
1962 M37
User avatar
m-37Bruce
1SG
1SG
Posts: 2340
Joined: Fri Oct 19, 2007 8:21 pm
Location: Midlothian,VA

Re: stalling out--help needed

Post by m-37Bruce »

That is good news, same pump I guess?
Bruce,

1953 M-37 w/ow

Retired Again

Keep Em Rollin'

VMVA
8543bob
SSGT
SSGT
Posts: 318
Joined: Fri Jul 10, 2009 9:02 pm

Re: stalling out--help needed

Post by 8543bob »

GOOD MORNING, SOUNDS LIKE TO ME SHE IS FLOODING, COULD BE A BAD FLOAT VALVE OR FLOAT??
I HAD A SIMNILAR PROBLEM, DRAINED TYHE CARB BOWL A COUPLE OF TIMES AND ADDED CARB CLEANER TO THE TANK. NO MORE PROBLEM.
GOOD LUCK
BOB
Post Reply