Humvee Cranking But Not Starting

[Hummer Guy]

I haven't started yet to diagnose this, but after finally receiving my humvee, it had dead batteries, so I got some new batteries and install them then try to start the truck but I'm only getting it to crank as if it's not getting any fuel at all. My plan is to check the fuel filter and lines and see if anything is clogged. My next step is checking the fuel pump. Is there anything else I should be checking as to why it's not getting fuel?

Another question, does anyone know what these wires are for in the circle that's by the glow plug smart box? I notice it was disconnected so I reconnected them.

Has anyone else ever got a humvee from govplanet that was running and it ended up not running when you finally got it?

 

[Action]

Are you waiting for the wait light to go out before you turn switch to START ? Does the wait light even come on ?
The connector is usually pulled apart to stop the engine from overheating.

 

[Hummer Guy]

Are you waiting for the wait light to go out before you turn switch to START ? Does the wait light even come on ?
The connector is usually pulled apart to stop the engine from overheating.

Yea, the light comes on, I wait for it and it still just crank.

How does pulling the connector apart stops it from overheating? What specifically that connector operates?

 

[MarkM]

The default for the clutch fan is on and hydraulic pressure from the power steering pump keeps it disengaged. If any part of the system fails the fan will stay on and cool the engine.

Mark

 

[OBX]

I haven't started yet to diagnose this, but after finally receiving my humvee, it had dead batteries, so I got some new batteries and install them then try to start the truck but I'm only getting it to crank as if it's not getting any fuel at all. My plan is to check the fuel filter and lines and see if anything is clogged. My next step is checking the fuel pump. Is there anything else I should be checking as to why it's not getting fuel?

I recently brought home my M1152A1 6.5T from Albany as a non-runner. Would crank but not start. After reading many of the contributions here from knowledgable members, decided to start with the IP. Today, after removing the top of the IP, I found the internal linkage fouled and stuck closed. Cleaned everything with aerosol brake cleaner, filled IP with fresh fuel then reassembled. That’s all it took! Started immediately.

 

[Hummer Guy]

That make sense, most likely I will try that first, did you end up taking the pump off to clean it?

 

[OBX]

That make sense, most likely I will try that first, did you end up taking the pump off to clean it?

No. However, I did remove the air intake duct and negative cable running across top of IP to generator for easier access to IP.
You need a “tamper resistant” five point T25 torx to remove the three attachment screws securing cover of IP. If you find the IP full of fuel, as I did, chances are your fuel pump and filters are not the issue. I used clean shop cloths to soak up the approximately 1cup of fuel present in the IP to see the submerged dirty linkage within. I had to use a flat tip screwdriver placed between the IP housing facing the firewall and the internal valve (?) to gently pry it free. Stop prying when you see the valve begin to move and begin spraying even more Brake-Free directly on that area. Liberal spraying of Brake-Free is needed to thoroughly clean the linkage and valve. use your finger to cycle the entire linkage many times to ensure it operates properly. I also cleaned inside the IP cover before refilling the IP with fresh fuel and re-installing cover. Re-install cable to generator before starting. I have additional cleaning of the engine bay before I re-install air intake duct.

 

[Crapgame]

Same situation, 2003 M1123, wait light comes one, acts like it wants to start but getting no fuel. I have tested both sides of the fuel/water filter cannister, have fuel going in and fuel shooting out.

I unplugged IP solenoid Wire #54A, have power to it, the solenoid clicks.

Cold Advance Sensor Switch showing continuity.

We loosened the rear 2 fuel injectors, only enough fuel to wet the hex collar came out.

I tested the rear glow plug on driver side, it is getting 18v.

So the fuel shutoff solenoid is getting power and "clicks" but the IP isn't getting fuel to the cylinders.

I have to get some alligator clips tomorrow to make a jumper to test continuity of Wire #569B.

Another symptom, the throttle cable is limp as a noodle, I tried reaching through the doghouse opening to manually rock the throttle valve but no start.

I did pour an entire bottle of Sea Foam treatment into the tank as well as 5 gallons of fresh Diesel.

Truck was processed into Preserved Storage 6-4-2018

IROAN March 2009, 132 miles since, labelled as a USMC MRC145A Radio Set M1123

 

[Mattguy]

Same situation, 2003 M1123, wait light comes one, acts like it wants to start but getting no fuel. I have tested both sides of the fuel/water filter cannister, have fuel going in and fuel shooting out.

I unplugged IP solenoid Wire #54A, have power to it, the solenoid clicks.

Cold Advance Sensor Switch showing continuity.

We loosened the rear 2 fuel injectors, only enough fuel to wet the hex collar came out.

I tested the rear glow plug on driver side, it is getting 18v.

So the fuel shutoff solenoid is getting power and "clicks" but the IP isn't getting fuel to the cylinders.

I have to get some alligator clips tomorrow to make a jumper to test continuity of Wire #569B.

Another symptom, the throttle cable is limp as a noodle, I tried reaching through the doghouse opening to manually rock the throttle valve but no start.

I did pour an entire bottle of Sea Foam treatment into the tank as well as 5 gallons of fresh Diesel.

Truck was processed into Preserved Storage 6-4-2018

IROAN March 2009, 132 miles since, labelled as a USMC MRC145A Radio Set M1123

Did you check the check valves in front of tank? No fuel on mine and check was frozen shut. Also check strainer sock in tank.

 

[Milcommoguy]

I might have missed it... was the resistance of the glow plugs measures? To be sure check them all. 1.5 - 5 ohms in that range would be good. I checked the temperature there to be about 55 degrees. That's a little cool to start without some glow action. Should or could be popping and a smoke-en a little. Even with the flow or drizzle out the injector line it may not be true sign of line pressure. Don't put your finger across it or you might just start... Don't think of it!!!

Lately a lot of fuel and IP issues.

Sounds like you'er all over it. Keep poking at it. Might just wake up Shrek...LOL

Sleeping GIANT, CAMO

GOOD LUCK

 

[Hummer Guy]

I manage to get it started today, I had just pulled the hose from the fuel filter and tested it. The fuel started squirting out like 2 seconds after I hit the switch so I plugged it back in and it started up. Now I just got some loud rattle at the generator, it only does it while idling.

 

[Crapgame]

I manage to get it started today, I had just pulled the hose from the fuel filter and tested it. The fuel started squirting out like 2 seconds after I hit the switch so I plugged it back in and it started up. Now I just got some loud rattle at the generator, it only does it while idling.

Think maybe the backflow valve on your fuel/water filter inlet was clogged or gummed closed? I was told that valve isn't really needed, by one of the professional HMMWV wrenches. I'm just a parts changer who can read the 3rd grade level TMs and the M998A1 AMG Troubleshooting TM.

Mattguy, I never knew that was a check valve at the fuel tank. I've read about the strainer "sock" issues though. Will survey the glow plugs for resistance as my next step, I'm thinking I'm having something Simple-Stupid that is the cause. I start to feel like some "dumb" inanimate object is getting the best of me.