Compression Test Injector Disable:

[McRat]

First, let me say I'm a tard.

I've always been either unplugging the FICM (LLY) or the individual injectors on the LBZ+.

I tried all the fuses on the LBZ today, and didn't find the "magic bullet" that disables the injectors and permits the engine to be cranked.

Well, DUH...

You have 2 bale connectors on the top center driver's side on all Dmaxes. The top one is mostly sensors, but the bottom one is ... drumroll ...

THE FREAKING INJECTORS! No lower (large) bale plugged in, no injector can fire. Funny thing is, I knew this since for awhile I was datalogging and had mapped all the bale connectors so I could see the injector timing.

Just unplug both (you kind of have to unplug the top to get to the bottom anywho), and you can crank till your battery dies without fueling the engine.

I imagine many folk already know this, but the question keeps popping up, and I'll probably forget again, so here's the Cliff Notes:

To disable the injectors for compression testing, unplug the bale connectors.

 

[duramaxdiesel]

I did not know that. Good info though. It might come in handy sometime. Thanks Pat!

Nick

 

[x MadMAX DIESEL]

I told ya that didn't work pulling fuses! Also while were on the subject on compression testing LBZs. The harbor freight kit WILL NOT work with LBZ heads

Good post though, its better than jumping the starter!

 

[Burn Down]

Good to know! Thanks Pat

 

[McRat]

Update:

After we did this, the truck had no throttle response, only idled. Not sure if it was cranking it with fuse(s) missing, or the bale connector.

But after reflashing the ECM it is back to normal. Pretty weird. Like a hidden limp mode.

 

[BLKLMM]

Glad u got it running again Pat, I did make it home at snail speed:roflmao: Thanks for everything,now gotta build it up and take it back to you to make some serious numbers

 

[Leadfoot]

I told ya that didn't work pulling fuses! Also while were on the subject on compression testing LBZs. The harbor freight kit WILL NOT work with LBZ heads

Good post though, its better than jumping the starter!

So I spent money for nothing

What will it take? Any adapters that I can buy for that kit

 

[BLKLMM]

It will not give you an accurate reading cause fitting hit on side of head but if i recall the Kent Moore kit reads and fits fine but needs a 90 degree angle to get to number 8 cylinder

 

[dmaxfireman]

the harbor freight kit worked fine on my lbz??

 

[McRat]

So I spent money for nothing

What will it take? Any adapters that I can buy for that kit

I'm currently working on a solution as we speak. I've ordered several different pieces to come up with a cheap and easy LBZ/LMM solution. Just the Kent Moore tip is about $130 alone (no gauge or other fittings). That's just abusive.

 

[McRat]

the harbor freight kit worked fine on my lbz??

I have both the cheap HF kits, and the best we could do with a HF tip was 2 turns, and it leaked on an LMM.

What sucks is the HF fitting have a different connector than the Kent Moore or Mity Vac pieces. HF kits are "non-standard".

 

[dmaxfireman]

yeah the fitting i used out of bens harbor freight kit when i though i blew a head gasket worked just fine on all eight cyls

 

[McRat]

The HF kits have changed over time, and that might be some of differences folk have reported.

 

[bullfrogjohnson]

Keep an eye out on eBay for the Kent Moore kit. I bought one for 30.00 bucks a few weeks back.

 

[McRat]

Problem is, the Kent Moore kit won't do #8 or any cylinder than has something in front of the glowplug, like twin charger mounts, steering shaft, etc. It has a very long straight section on the gauge assy that is metal. Only #8 is a real problem though, other stuff can be removed, but is a PITA sometimes.

And KM doesn't have an angle adapter for their stuff.

 

[JoshH]

I borrowed a Snap-on glow plug adapter from a buddy of mine and took it with an LBZ glow plug to a machine shop. I had them make me an adapter to fit my head. It looks like the picture below, but the threads are further down the shank like they are on an LBZ glow plug.

 

[GeorgiaDuramax]

Good to know!

 

[madmatt]

I have a 90* that works on my Kent moore adaptors:thumb:

 

[BLKLMM]

I have a 90* that works on my Kent moore adaptors:thumb:

Nice:thumb: where did u find it?

 

[madmatt]

it came with one of the kit moore kits I bought