Hmmwv 6.5 starting problems

Hi,

I just started having problem with firing up the hmmwv. Sometimes it fires right up and sometimes it is just pouring white smoke out of exhaust and no start. I got the truck for about 3months ago and when I first got it cranked maybe 10 seconds on new fresh batteries and fired up, poured some smoke at the start up and was rought for some seconds and then acted normal. It always started the 2 first months, sometime almost instant and sometimes it cranked 5 seconds and then started with some smoke coming out. It may sound like it is rought in the first seconds when the engine is fired, almost like a knocking sound, but the sound dissapears after 20-30 seconds and is then normal. The smoke out of the exhaust smells diesel, unburnt fuel when it is not starting up. No lack of coolant

When it starts and I ride it to it gets normal operating temprature I can shut it off and start it up instant with no hard starting

I just installed new glow plugs and hoped that would fix the issue but it didnt. The glow plugs i pulled out looked good and were tested to 1,9-2,2 ohm. I have also drained the water out of the fuel filter box and checked filter.

The wait light stays on for 7-10seconds when the engine is cold and I have measured that power is getting to the the glow plug connectors

Any tips? Can it be the injectors?

The truck is a M1045a2

From 2mas-

Hi,
Im new to the forum. I just started to experience this with my M1045A2 Humvee. Im curious on what may be causing this and look forward to the feedback from other more experienced users.

Hi MGC, do you have the same problem?

Are both of you seeing the voltmeter dip down during the glow cycle? If not, the plugs are not heating up leading to this problem.

I measured that power was getting to the GP connector cap. But I will take an extra look on the voltmeter to see if it drops and then get up to normal again.

Thanks for the tip

Does sound like the glow plug controller. There are several threads on the site you can search out. The motor is common to both HMMWV and CUCV, so search both sub-forums. There are several options ahead once troubleshooting is done, involving replacing the control box or making a manual glow plug circuit or other solutions. It could just be some wiring needs cleaned and reconnected.

I'll ask the question before someone else does... Do you have a supplemental grounding harness? If not, do it. It will help many things, possibly this issue even.

Welcome to the forum.

Bulldogger

Yes additional grounding added. I couldnt see the voltmeter drop and go up again after glowing. The voltmeter shows yellow even if the batteries are fully loaded. I think there is an issue with the regulator on the generator also, sometime it is on green when the engine is running and suddenly it drop to the yellow. I have cleaned the wires and put it back together

Noticed after i turned the igniton today and it wouldnt start I heard a "clunk" sound coming from the PCB box. Like something was turning on then off every 6 seconds

2mas- said:

Yes additional grounding added. I couldnt see the voltmeter drop and go up again after glowing. The voltmeter shows yellow even if the batteries are fully loaded. I think there is an issue with the regulator on the generator also, sometime it is on green when the engine is running and suddenly it drop to the yellow. I have cleaned the wires and put it back together
Noticed after i turned the igniton today and it wouldnt start I heard a "clunk" sound coming from the PCB box. Like something was turning on then off every 6 seconds

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Which alternator do you have? 60 amp, 100 amp or 200 amp? Different troubleshooting for each of those. The voltage regulator may be able to be adjusted. Most of the time it is replaced though, in my experience.

It sounds like you have more than one problem, though they may be interconnected or caused by the same failure.

BDGR

I got a 200amp alternator

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