I just installed one of thoese 30psi westach fuel pressure gauges. I fired it up and it went straight to 15-16 at idle....Then driving it goes to about 10-11 psi ....After a few minutes, it quickly drops down to about 4psi and then works the same as if it was at the 15 psi mark. Full thottle it goes to 0 ps1...But when it went down to 4, it was like someone shut the gauge off. So, i was driving at the 4 psi mark and decided to floor it....The gauge jumps up to the 15 psi again and works fine all the way home. Its like it dows this everyday after i fire and drive for a few minutes.....But then flooring it, brings it back to the 15psi and it doesnt jump back down til i shut the truck off and it cools off....I have the gauge double grounded and all connections are tight. I dont want to buy a new lift pump if i dont have to. I have no symptoms of dead pedal or loss of power....Ideas?

 

Check the pressure manually.

I am having the same problems with my Westach fuel pressure gauge right now.

I messed with some of the wires that attach to the sender and now it only reads 30 psi whether the FASS is running or not.

It probably needs a new sender but I will check fuel pressure manually in the morning.

 

2nd on manually checking the fuel pressure.

leeboy,
I'm guessing you still have the stock lift pump, have you ever replaced it? I had one give me similar results. Fuel pressure would drop while cruising and if you floored it the pressure would go up. I attributed it to a flaky bypass valve on the pump.

 

Update:
Checked mine manually this morning. 30psi+ of good fuel pressure.
Either my Westach sender is bad or there is short/bad connection somewhere in the wiring to the sender.

 

Hey guys, ya i have the stock lift pump still...I am going to pick up a manual gauge this weekend. I guess, i will tape it to the window wiper or something and see if they match....

 

The sender is probably bad.I went through 3 or 4 senders doing the same thing before I ditched mine and went with a diprocal mechanical guage with a needle valve and no isolator 3 years ago. No problems since.

 

Is the pressure transducer remotely mounted?

If its mounted someplace where the engine vibrations can hammer it, there may be problems. I remotely mounted mine, when I installed them in AUG of 2000.

 

Nice Job, mines just simply screwed into the filter housing...

 

use a ohm meter and check resistance on your sender to ground it should vary depending on your pressure. Open lead to the gage will read 0 ground that lead it will read max.

 

I havent found a cheap manual fuel gauge yet....What i did notice was, once the psi drops to 4psi, if i shut the truck on and tunr back on...it goes right back to 15 psi for a while...or somwtimes the whole ride...

 

Did you ever find a solution to this problem?

 

if you in Can. Princess auto has hyd pressure guage on sale 2 weeks ago $4.99 0 to30 lbs and you can buy 10 feet 1/4 of hyd hose for about $10 to attach it.

 

I bought a $20 gauge and screwed it into the other side of the fuel filter canister. So, when one went down to 4psi, so did the other. So, it doesnt look like a gauge problem. I ordered a new Fass DDRP that is goin in tomorrow, so that should fix that gauge...