No Current to Injection Pump

[Jon0249]

Feeling pretty stupid today, but I'll swallow my pride and beg for help!

Enlisted a friend's help to jump my M998A0, and he got the cables switched for a short time. No telling what damage was done, but I know for sure I am not getting power to the IP. Glow plug light cycles, starter works, lights are fine, but no fuel.

I'm fairly certain there's no fuse block or fusible link, so not sure where to start. Tracing the elec source to the IP is gonna be tough, so maybe someone has had a similar problem?

Thanks,
Jon

 

[porkysplace]

Probably fried the power control box.

 

[Jon0249]

Good news, I now have power to the IP. Don't ask. Now it just won't start. Aren't there resistance tests I can do on the box? I opened it up and there is no sign of obvious burnt components, so I'm hoping it's still good.

 

[papakb]

When you turn the start-run switch to the on position you should have power to the #54 wire on the top of the IP and you should hear the solenoid in the top cover of the IP click. This is the solenoid that opens up to allow fuel to flow into the IP. If it isn't clicking then you should replace it. It's pretty simple, 2 wires and 3 screws should get you going again.

Kurt

 

[Jon0249]

Thanks for the tip. Fortunately, i found the problem. When I reinstalled the alternator, I might have missed the ground cable... Funny how I now have power. And fuel.

Focusing on the EESS box now. No visible damage, but no way to test it without the STE/ICE, unless someone knows a way. GPs are good, it cranks like it should - I can hear the solenoid in the EESS engage. I'm stumped.

 

[NDT]

Confused here, you said you found the problem but are you saying it stiil won'f start?

 

[Jon0249]

Yes, found the IP power issue (operator error), but won't start now. I'm finding dead GPs, so starting there.

 

[porkysplace]

Yes, found the IP power issue (operator error), but won't start now. I'm finding dead GPs, so starting there.

It should be warm enough in Dallas that you don't need the glow plugs.

 

[Jon0249]

I agree, it should be. So why won't it start? I'm in the process of making a grounding harness, mostly because it'll make me feel more comfortable, jut not sure if it's a contributing factor.

I know this sounds stupid, but aside from controlling current to the GPs and housing the solenoid, what other purpose does the EESS serve? What does the circuit board do? At some point, with fuel and compression, this thing should start.

 

[papakb]

Since there are only 3 things a diesel needs to start, yes it should. If you have fuel, air, and compression that's all that's necessary. Below a certain temperature it needs the glow plugs to cycle but I think Dallas shouldn't be that cold this time of year. Current temp is showing at 77 degrees and that's above the set point.

The grounding harness is something every HMMWV owner should make sure is installed as it makes up for poor electrical bonding throughout the HMMWV body. It's easy enough to make with a handfull of ring lugs and some #8 gauge wire. Plenty of information on them here and on the G503 site.

The PCB provides reverse polarity protection among other things. Keeping the pfc's in the maintenance shop in line. The newest boxes with the third connector on them also have some diagnostic capability if anyone ever finds out what the test box is supposed to look like! LOL

Kurt

 

[Jon0249]

Agree with everything you said, Kurt. I see so many folks that are advised to replace the EESS under specific indicators of failure, and I'm not experiencing any of them. The WTS light hasn't changed in the 2 yrs I've been driving it; the GPs are dead, but I'm well above the target temp. However, from day 1, I've always needed the WTS light to go out before starting. On a couple of occasions, I've started in cold weather when the WTS light wouldn't turn off (first hint the GPs were going), but generally, it seems like I've needed the GP on initial daily start.

This all began when I blew out my fan clutch. It's been sitting for a few weeks after being a near daily driver for 2 yrs. Fan clutch was replaced, and when I went to start it, the batteries were dead. Not unusual, I suppose, given a couple of LEDs that stay on, but now I can't get around what seems to be fairly straightforward indications. So the grounding harness and GPs are must-haves for me, then I'll see how that goes.

Thanks for the feedback.

 

[porkysplace]

Have the fuel filters been changed ?
Have the fuel lines been changed since you owned It ?
Have you made sure your getting fuel to the IP and it didn't lose prime.

 

[Jon0249]

Fuel lines haven't been changed or damaged. Fuel filter is due for a change. I suspect lost prime in the IP - how do I know for sure? And how do I regain it? Does that happen after sitting for a few weeks?

 

[porkysplace]

Fuel lines haven't been changed or damaged. Fuel filter is due for a change. I suspect lost prime in the IP - how do I know for sure? And how do I regain it? Does that happen after sitting for a few weeks?

Old rubber lines can cause it to lose prime .
DON"T USE STARTING FLUID
[h=1]HMMWV A1 Troubleshooting[/h]
[h=1]M998 with 7k miles, won't start[/h]
[h=1]: Ran out of fuel on a HMMWV[/h]
[h=1]Opened drain and it stalled out[/h]
[h=1]Ran out of fuel on a HMMWV[/h]

 

[Jon0249]

Final note: Gunny (yeah, I named him) started right up this morning. Fan clutch working as it should after replacing it. WTS light was on for literally only half a second and the engine started after 8-10 seconds of cranking. After sitting a few weeks, I suspect fuel was dropping down and just needed a good cranking. Charging gauge in the green again after removing, cleaning and reinstalling the alternator. EESS unit exhibited no signs of failure, and it is in fact still working well. All glow plugs tested dead, so all were replaced with new from the super service oriented folks at Mac Motors. Still have to build the grounding harness, but can do that in confidence all other systems are working. Thanks to all of you for the probing questions and advice.

Also: The EESS unit was a bear to get out, as the pressed nuts on the underside were stripped and spinning, making it near impossible to get a vise grip on them. Drilled them all out and used body panel nuts/U-clips. Works perfectly and no backup necessary.

Jon