limping the fuel system

honda_man_300ex · 10-11-2008, 08:04 PM

Alright guys i've discussed this before on diesel place and at the time had it fixed or so i thought. i have an 05 and have an edge juice w/ att usually on level one and a diablo sport usually on level 2(65 horse); 4 inch exhaust and s&b intake along with an air dog.... i first put the edge on and was having limping problems. talked to some people and they said a lift pump will solve your problem so i done that and it pretty much fixed the problem unless i turn the edge up on 4 or 5. so i researched and found out that it could be my fuel pressure regulator but it didn't effect me unless i turned it up so i didn't do it. now i changed the filters last weekend and ever since it limps just cruising at 65-70 and very constant..... i have a shim kit on the way and also rechecked all my filters. took the programmer and edge off and it still does it..... is it possible that my fpr has just totally shot shit? the dealer i took it too is being no help either cause of the air dog lift pump system. they say that's my problem but i don't see how since it's still providing constant pressure to the pump? any help would be great guys i need this truck back bad as it is my main transportation and is pretty much un drivable on the interstate. thanks alot.

**daddysLBZ** · 10-11-2008, 08:09 PM

FRR is gone probably..Are you getting engine limp???And the truck was doing this before the Edge???It should not do that without a tune that demands fuel.Check the FPR.Do ya have some loping/surging idle with it???

**BigRedChevy** · 10-11-2008, 08:38 PM

Are you sure the lift pump is working? If it has died on you then the restriction would put you into a low rail pressure limp.

**daddysLBZ** · 10-11-2008, 08:41 PM

Good point Big red!!Would not let enough fuel to the rail,am I right.Even in stock demand..

**BigRedChevy** · 10-11-2008, 08:53 PM

That's right, that is why i liked the TTS pumps. They are a flow through design.

**daddysLBZ** · 10-11-2008, 08:56 PM

Flow thru meaning if they fail,they fail still with the flow not impacted???Like a fail safe safety deal to let diesel thru no matter what?am i on track with that thought,or does that sound dumb??

**BigRedChevy** · 10-11-2008, 09:17 PM

That is exactly what it means. If for some reason it fails there is no or i guess very minamal Restriction. It would have no problem running with the pump off. Now running a big tune would be a different story, but a stock or mild tune would be no problem.

**daddysLBZ** · 10-11-2008, 09:19 PM

Cool,thanks fer the reply...

honda_man_300ex · 10-12-2008, 01:44 PM

My air dog is suppost to be a flow through design as well and i talked to pure flow and they said if the dumby light is going of after the key is turned your getting atleast 5psi from it. i'm planning to take the fprv out and put the shim kit in it. it isn't as easy to limp it in stock form now(leaving the pump hooked up but tuners off) but still does it. they recommened check the fprv first then if that doesn't fix the problem they would start lookin at the pump. i didn't have the limp problem until i put the edge on it..... you think it could have been something lingering in the back that i've just neglected and now it's a major problem? i don't have any idling or starting problems so i don't think it's my injectors. no smoke at idle either. i also wondered if i could by pass the pump by putting a hose fitting between the inlet and out let hoses and just unhooking the pump totally? i really appreciate all the info guys! ps does any one know of any good diesel mechanics in the southeast missouri area or up around st lou?

**ob_1jr** · 10-12-2008, 02:00 PM

u know that the LLY has had problems with the #2 and #7 injector harness chafing and could cause problems like you're having. I would at least check that out before digging too far into the fuel system. Are u sure that you are having and engine limp and not a tranny limp? You are getting some codes and a check engine light when this happens right?