Slow to Start

[Economist]

I am starting to work through the issues on my (new to me) M998. It started to get a little cooler here, finally. The HMMWV was starting a little slow on the first start of the day. I thought it must be batteries. So, I dropped two new 800 CCA, gel batteries in here. She still starts a bit slow on the first try of the day - Cranks for 8 to 10 seconds before firing. I am waiting for the glow plug light to go out. Any thoughts? Glow plugs?

Thanks for any help.
-Economist.

 

[denubilo]

I cast my vote for the starter not cranking fast enough!

Had a similar trouble on my Dodge Diesel.

 

[Economist]

Did your problem go away once you got it warmed up? On the second and third starts of the day, it is very quick to start.

 

[denubilo]

slow starting

To tell you the truth I cannot remember.

You probably will get better advice from the other guys It was just a shot in the dark from me.
I also do not have glow plugs.

 

[Wolf.Dose]

The old 6.2 L D starters are known to be not reliable, so the are replaced by a new model. Number is 6598N and so available.
Wolf

 

[Economist]

The problem continues, but sporadically. It is definitely worse at start up. I am looking in the TM's to find out how to test for a bad glow plug. Anyone have any experience with this?

 

[emmado22]

What PCB box do you have? Check/clean all battery/starter connections for corrosion..

 

[Economist]

Apologize for asking, but what is a PCB box?

Will check all connections tonight.

Thanks.

 

[emmado22]

The "brain box" that controls the glowplugs. Look for it under the dash, drivers side, It has a BIG canon plug going to it, and a big canon plug on the engine compartment side.. Let us know what the sticker says.

 

[Economist]

Will do so tonight and post tomorrow. Many thanks.

And, by the way, the fuel cans are excellent. I sent several others from the HML (Hummer) forum your direction.

-Economist.

 

[SETOYOTA]

cranking slow would not be glow plugs. They have nothing to do with starter speed. if your glow plugs were bad it would turn over fine but would be hard to start if at all. After it did start it would seem to have a skip for a minute and smoke a bit.

My bet is a poor ground. Check the large nut that the battery cables are grounded too. It is on the frame behind the battery box. Take it apart and clean with a wire brush to remove any corosion. That should help.

 

[TedG]

When working on the PCB, never plug or unplug cannon connectors while batteries are connected.

All hmmwvs should have the ground wire kit installed and most/if not all auction hmmwv's did not have them. It connects the left rear engine head grounding point to: PCB mounting screw, Generator ground, dash/fire wall ground (above fuel filter) and finally the grounding stud on the starter. You can buy these from suppliers or make one.

Picture shows the harness installed on engine.

Good luck!

 

[xmiltm998]

i had the same problem about 2 years agao. i changed all the glow plugs and the glow plug control box and that fixed the problem. i got the new control box and glow plgs from kascar

 

[Economist]

When working on the PCB, never plug or unplug cannon connectors while batteries are connected.

All hmmwvs should have the ground wire kit installed and most/if not all auction hmmwv's did not have them. It connects the left rear engine head grounding point to: PCB mounting screw, Generator ground, dash/fire wall ground (above fuel filter) and finally the grounding stud on the starter. You can buy these from suppliers or make one.

Picture shows the harness installed on engine.

Good luck!

I looked at the truck and it does not appear to have the ground straps. I will try to track one down from a supplier and see if that helps.

 

[Economist]

What PCB box do you have? Check/clean all battery/starter connections for corrosion..

Photo of PCB box attached. I am trying to find the grounding straps Ted posted about. Does the PCB box tell you anything?

 

[TedG]

Ground harness: 535-A1- Ground Kit, 4 Wire, A, B, C, D, $70 at Kascar.

The old Prestolite control box might be tired. I use Yellow Label KDS with matching GPC sensor (yellow band). OR the latest EESS control box.

Stay away from the control box that requires a separate glow plug harness.

 

[Economist]

Excellent. I ordered the grounding strap. It is in route.

I have lead on a new box. [FONT=&quot]PN# 6110-01-542-7901. Supposed to be the latest and greatest. Do you know if that requires a separate glow plug harness?

FYI, I saw rear bumper, D-Shackle brackets on clearance for $6.00 each at KASCAR. Seems like a pretty good deal to complete the back bumper setup for me. Since shipping was covered for the grounding strap, I tossed a couple in my order -- in case you are stocking your HMMWV warehouse.

-Economist.
[/FONT]

 

[emmado22]

That NSN 6110-01-542-7901 / KDS part # CR-2701 is indeed the latest PCB box out there. I am running one on my M998 with KASCAR non swelling glow plugs.. It does NOT have a seperate GP Harness. (Only the LAU style box had this harness, and it burned up some HMMWV's before the DOD discontinued it's use.)

The Prestolite you have is a very old unit.

Battery conditon is also very important. Make sure they are clean/ charged/ and all connections tight. I love the Hawkers that I have in my M998 and M35A2.

 

[Economist]

That NSN 6110-01-542-7901 / KDS part # CR-2701 is indeed the latest PCB box out there. I am running one on my M998 with KASCAR non swelling glow plugs.. It does NOT have a seperate GP Harness. (Only the LAU style box had this harness, and it burned up some HMMWV's before the DOD discontinued it's use.)

The Prestolite you have is a very old unit.

Battery conditon is also very important. Make sure they are clean/ charged/ and all connections tight. I love the Hawkers that I have in my M998 and M35A2.

Is swapping in the new box, plug and play? Given the age of my Presolite, I am inclined to swap it out. Any domino effects I need to be worried about?

Batteries are brand new and fully charged. That was my first thought as well. I am cleaning up connections this weekend.

Thanks.

 

[TedG]

Switching your old box to the new box is plug and play (disconnect batteries first). With the old box, it is best to spray a lubricant on the cannon plugs prior to disconnecting or you can bust the threaded nut. Some hmmwv owners have had bad luck with kascar glow plugs breaking off. I have not but I did switch to the version you see on ebay that are sold in IN.

With the ground harness, clean ALL grounting points, especially the dash ground stud on both sides of the fire wall. I use star washers (internal/external toothed) to bite into the metal/aluminum for good continuity.