what tools do you need to check fuel pressure on a 98 24 valve. I know i heard you can plump it into the cap on the filter housing but on my 01 that cap is plastic

 

is it a 24 valve or a 12 valve? 98's were 12 valvers and 98.5's were 24's.

 

24 valve
i am pretty sure
i havent seen the truck

 

The 98.5 and 99s and 00s have a metal top on the fuel filter. The plastic ones are on 01s and 02s There are 2 brass plugs in the metal top. The one on the left is post-filter and the other one is pre-filter.

 

put the guage into the one on the left. 1/8"NPT.
98.5's -00 have the metal top. Don't tighten it too tight, don't ask me how i know that but the Jb weld is still holding.

 

So tap the FP Gauge into the Brass bolt closest to the engine?

 

It's the one closest to the center of the cap, that one is post filter. the one furthest out is pre filter.

 

Why don't you just tap into that banjo bolt there on the VP?? I just picked up a Vulcan Performance fuel pressure test gauge and it has a fast connect brass fitting that screws right on, right there. On my 02 it's the banjo bolt with the cap on it (that protects it) but it's like a tire valve stem which is depressed when the gauge is hooked up, allowing the gauge to monitor the FP. I have to use some light pressure with pliers to get it all the way on. But that gauge setup is well thought out and is long enough to hold in your hand hooked up while sitting in the drivers seat, starting your rig. I've seen em on Ebay for half of what they want for them new. Even then, at $50 plus shipping new, it's a QUALITY test gauge setup that's extremely accurate that makes checking either the fuel pressure @ the VP or the accuracy of another gauge VERY simple to do.

 

thanks for the responses guys. I guy i am asking for says he truck is just dying and someone told him it was the lift pump so he wants me to replace it. i told him if it just dying it is either the tps or his VP-44. The codes he got off they key trick we
po720-cant find what this one is
po628-low voltage at the lift pump
po573-High voltage at brake switch

does the po628 mean like the lift pump is not getting full twelve volts or is it just bad

 

His is a 98.5 and they don't have that valve on the banjo bolt. That valve came along in '01.

 

On a 01 on the side of the VP44 you will see a banjo bolt with a plastic cap. You can get fuel pressure readings from there.

 

But he has a 98.5 -- No valve on the banjo bolt.

 

thanks for the input guys. The truck i am going to work on is a 98.5 and my own personal truck is a 2001

 

Sorry about that got confused in his orginal post. Thought he was wanting to know on both trucks.

 

Can't he just screw a 0-30 psi gauge on to the fowardmost pipe plugged port on the fuel filter top to get a pressure on the pump bump?