12 Valve Cummins Isues

jayphizzle · Jun 15, 2015

The boost reference tube is a small 1/8 poly tube that goes from the intake plenum to the rear of the AFC housing on the back of your injector pump. Some older models ran from the discharge side of the turbo. All it does is tells the injector pump how much more fuel to provide by sliding the rack forward. Mine cracked a fitting there before and went to crap! Ill find some pics and post up.

EDIT

Attached is a cut away of a p7100. The arrow below "Aneroid Fuel Control" is pointing directly at the boost reference hole. You should have a tube that connects here. If there is a leak in that tube it will run like crap!

xjmarc · Jun 15, 2015

Thanks I'll look at it when I get home.

Craig_c · Jun 15, 2015

Has anyone worked on the truck? Slipped timing could also cause this

xjmarc · Jun 15, 2015

The boost line is fine but I did find my shutdown solonoid which I replaced back around December is no longer bolted down. The bolts are gone. Guess I should have put locktight on them even though I torqued the crap out of them. So I guess I get to find new bolts. Oddly enough it still starts and turns off fine but I'm wondering if it doesn't pull the fuel shutoff arm up enough if that's why I'm not getting enough fuel.

Humpy · Jun 15, 2015

Yes^^^ that's your problem... My bolts stripped out and it was a turd... Your exactly right it's halfway on and running like ****... Bolt that back down and u will have less of a turd... Stock 180 pump 12v is no powerhouse lol