My lift pump quit working and so did the injector pump(surprise, surprise). The dealership replaced them under warranty and relocated the lift pump to the tank. Ever since I got the truck back, it does not seem to have the power it use to. I have been told it is because the new lift pump is not supplying the injector pump properly. I tested with a pressure gage with results of 7.5 psi at idle and < 4 psi driving. When I questioned the dealer, I was told that these pressures mean nothing and the only way to properly test the pump is to check its volumetric flow rate. Has anybody experienced this problem and if so, what is the fix to get my power back? All info is greatly appreciated.

 

WELCOME TO DTR. the lift pump won't cause a power loss. If you need more power you will have to chip it, or injectors, or both. Where did your power go? I don't know, but a different lift pump won't help

 

OMG!!! Blackdiesel, IMHO you nailed it right off the bat!!! I was really expecting a "slam" of the in-tank unit and it being the cause of all evil. What a breath of fresh air!! Personally I have installed a few intank units and the only injection pump I've had to replace with one in place had the lift pump installed previous to some already suspicious drivability issues. Not saying (EVER) that any particular lift pump in general will "save" your VP, but I'm not sold on the "you have to have over 10 psi all the time" theory.

I also highly doubt that the lift pump is the source of your problem. Not sure what "power loss" or how you metered this (not good wording), but I would look elsewhere. Maybe a subtle difference in the VP itself??? hard to tell.

No Body

 

While I don;t care what LP is in the truck, 4 psi is low and is below factory specs (see FSM, the fule pressure must be 5 psi or more). Low LP pressure can cause lack of fuel delivery to the IP and subsequent poser loss; if you have 5 psi under load, your VP is getting all fuel it may ever need, unless your truck is bombed (per Blue Chip site).
-P

 

Thank you for all inputs. I define power loss as not being able to pull a load like it use to. Dropping gears on hills I use to clear in high gear. When the truck is under load (pulling a loaded trailer), no black smoke? Hard to get it moving when first started after setting overnight. Unable to pass grandma going uphill. (look out going downhill).
I want to add a computer (Edge Juice), but not burnup another VP-44.

 

After reading some of the other threads, I pulled the codes on my truck. They were PCU P 1693 and ECU P 0234. What do they mean?

 

0234 is turbo boost limit exeeded, it could be a stuck waste gate. possibley putting you in limp mode, hence no power

 

https://www.dieseltruckresource.com/...ighlight=po234

 

Thanks johnh, that article pretty much described my problem to a tee!!

 

Just food for thought. I'm not an expert by any means but I was told by my injection shop that when an injection pump goes out there are usually small particles of metal that enter the fuel lines and can cause clogged injectors. My injection shop recommends going through the injectors before reinstalling them after an IP failure. Might want to replace your filter also. Sometimes the dealership cuts corners.

 

If you are refering to your 93, then "yes", I do agree with the metal krap. On a VP truck I would say you would most likely be wasting your $$$. I've got hundreds of VP installs under my stupid corner cutting dealership tenure and have yet to have a "drivability" issue after installing one.

No Body

 

I took the turbo off the truck and found the waste gate linkage froze. Repaired linkage, cleared codes, truck runs MUCH better!
Thanks to all for help!

 

Good deal, glad you got it worked out.