I've had my truck about 3 weeks and I installed my gauges, BHAF, and Vulcan lp relocation kit last weekend. I was only able to drive it for a short time after the install, and then a few miles today, and now I have a couple of questions.

First, my lift pump was acting weird when I first moved it down to the frame. It initially ran 14psi at idle, and about 11 psi WOT, then when idling in the driveway the fp jumped down to 6psi. I could tap the throttle and the pressure would immediately jump back to 15psi. I could hear a different sound coming from the lp for the different pressures. It did this intermittantly that day. Then today it did it again when I first started the truck, but once I started driving the pressure didn't drop below 11psi agian. Should this be cause for concern???

Also, I was wondering about my boost pressure. I think I've read where I should get about 20 to 21 psi with my setup (no boost elbow or fooler). Well, I wasn't able to get more than 16psi today. I was running empty, but I did tackle a few nice hills. It would go to 16 fairly quickly, but never go higher. Is this normal??

Thanks in advance
Brad

 

I would watch and listen to the LP for awhile. It sounds like its starting to go... But It could be just a loose wire too. So double check all your work. Make sure you got a tight fit on the power connector.

As for boost it sound low. It can get 20 PSI in just about any gear. I would check your boots and your wastegate. The wastegate might be stuck partial open.

 

The pressure fluctuations are caused by a bad checkball and/or seat in your lift pump, It's a very common reason for these LP's to fail. Afraid the pump will have to be replaced.

 

Yeah, coming in to work this morning it was jumping around a good bit. It never goes below 6 psi, but I would prefer a steady pressure. I think I'm going to try a Holley pump.

Any other thoughts on the boost numbers???

Brad

 

Your boost depends on where you are taking the pressure reading. Should be around 20 to 21 at turbo and you will probally loose about 3 psi through the inter-cooler and intake, so about 17 or 18 at the manifold on stock truck. Plus your guage could be off by 1 or 2 psi.

 

My boost gauge is connected to the 3/4" port on the block just behind the fuel filter housing. I did manage to get it up to 18 psi today. Is this correct for a stock truck with the gauge in this location??

Thanks
Brad

 

thats where i put mine and i've hit 20 to22 psi and i have no box or anything

 

18 to 19 lbs. is ok for a stocker w/stock exhaust in this heat. You'll pick up a coupla pounds when the weather cools off.

 

Yeah it's been super hot down here since my gauges have been installed.

How would I go about checking the wastegate? I don't even know where it is.

Brad

 

I get 19 without my boost controller......

 

Your wastegate is on yer turbo. I don't know about testing it....I guess you have to be able to see it.