your lift pump is shot.

my does the exact same thing when i first start it on cooler (50* to 60*) mornings. it does not react to how much i am pushing on the go pedal, it just does whatever it feels like. very abrupt pressure fluctuations 5-13-5-9-5psi etc etc. mine is NOT a vibration problem. after a mile or so it will calm down and act normal and hold steady. i also have a new fuel filter. it started doing this every so often about 1.5 months ago, the first day it did this i went to Cummins and bought a spare lift pump and have it behind my seat for when it reads zero.

Pat

 

ok i am going to change that filter soon, so if it still acts up i guess it is the lift pump. i change the vaccum line to the intercooler piping before the intake. is this going to be ok? i was a little worried about drilling into the intake itself. do i need to drill into it to get the most accurate readings?

 

I would, it's not hard to drill. Just unbolt it and take it off before drilling, and clean it real good before re-installing.

 

Why don't you just remove the pipe plug in the head, get the correct adapter and read the boost there?

 

but would the piping cause for a false reading?

 

What piping? You would just adapt down to the 1/8" compression tube that comes with the guage.

 

i did use the compression fitting that came with the gagues but i tapped into the intercooler piping on the drivers side after the intercooler and before the intake on the motor. that piping. what pipe plug in the head?

 

There is a 3/4" pipe plug that you remove with a ratchet and no socket(four sided hole). It's on the driver side of the truck near the firewall.

 

i could accurately read boost from there? is it not accurate in the intercooler piping?

 

I would think it is, somebody else might have suggested otherwise, but not me. I like the pipe plug thing, no drilling and taping!!

 

yeah, do the pipe plug. thats where i put it, as well as others, and it is easy and impossible to screw up. just get the adapters to go from 3/4 inch to 1/8 in and run your boost line from there to your gauge. i would recommend a pressure snubber if your boost gauge begins to rattle. i tried a needle valve and rubber hose and it didnt work but the snubber stopped the rattle. i got mine from McMaster-Carr for $8, 1/8npt with a .04 orifice.

Pat

 

If you have already installed in the intercoller tube, I would just leave it. You will get the same reading from there as the head, and if you move it, you will have to plug up the hole where you have it now.
As for the fuel pressure thing, I would get a new lift pump asap, and keep it in the truck, so you can change it when your dying pump finally dies.

 

i've heard about the whole lift pump problem, but how often every year am i going to have to replace that thing? i would like to get something like the fass system if the lift pump is going to be a real porblem but i gotta save up for that. also how i can i increase the boost pressure? i've heard of a turbomaster but what is it? would a plug in box help add boost or is it all fueling? if so how much boost can i acheive?

 

Increasing boost without the extra fuel is pointless. Get a box and then up the boost. I've got my boost gauge in the plug in the block and have had it there for 3 years. No problems here. The turbomaster helps control the amount of boost you push. Adding it will do nothing unless you have a box.

As for the fuel pump problem, save up and get a FASS or something else. My roommates truck is doing the same thing.

 

Personally I like the turbo master, you can adjust your boost, whereas if you use a boost elbow you only get what the orifice dictates.