[beheivjer]

my 98 seems to be running out of fuel and doesnt like to start right away what is the stock fuel pressure on my 98 gt. any ideas thanks guys/gals

[MustangMatt96GT]

I believe its somewhere between 35 and 45 PSI! For somereason 40 PSI sticks in my mind!

[beheivjer]

thanks that what i was thinking the killer is i put a pump in it last july and its starting to go already. it was a pain changing it on a hoist and this time i have to do it on the ground

might just have to park the car for a while and drive the 79 while i finish my kitchen remodel and my garage build maybe 3 weeks then ill have a place to do the job.

[ILUVSTANGS]

the fuel pressure on a '98 gt with the engine running is 30-45 psi.
key on engine of 37 - 43 psi...
hope this helps.....

[ILUVSTANGS]

that was engine offffff.....37 -43 psi way toooo earily for this...

[beheivjer]

thanks i guess im just going to put my fuel pressure gauge in that ive had sitting around for almost a year now

[beheivjer]

well acording to my guage it is reading 30 psi while running and flutters down below every so often and when im hard on it it runs up to about 35 but thats it. I did change out the regulator and it is atleast up to much now instead of the 20-25 i was running.

so fuel pump? or inertia switch? if i trip it and start it it runs up to 35 at idle but only once and then the next time its back to 30.

[ILUVSTANGS]

a quick question....when was the last time you changed your fuel filter????
it could be the issue here!!
and are you the original owner.???...maintenance wise.. the other owner may not have taken good care as in what kind of fuel they bought...
dirty cheap gas leads to clogged fuel filter and fuel pump filter and dirty injectors and so on....
let us know!!!

[beheivjer]

new pump new filter im a autoparts slaesman, i know the drill. did both of these when in july last year i bought the car in feb 06. so previous owners flaws would have shown long before now. all the injectors were of and pressure checked in june of last year when i swapped in the pi manifold

[ChrisJ]

Sounds like if you flip the intertia switch and it runs good then it starts runnign bad again...I would say it would be the intertia switch...

[Casper98GT]

well you cant exactly just "flip" a swtich when talking about the intertia switch.

Why would you even consider the inertia switch ? When you have I.S. problems its usually a crank but no start. What exactly is it doing, you will have NO fuel pressure if you have a bad I.S. Its a fuel cut off. Find the I.S. and hit it with youre hand and see if it pop's up. If it does push it back down. If you honestly have youre mind set on it just jump the wires and rule it out.

[ChrisJ]

I have seen a faulty inertia switch short itself and give false readings and such...Im just trying to get him to rule thigns out...

Also how exactly are you reading the fuel pressure? I know you said a gauge but did not know if you might ahve tried another method...

Also how does the car run when it flutters?

Could all wind up being a bad sensor or gauge...

[Casper98GT]

Im just saying the I.S isnt the problem if it starts. It could very well stall out due to the switch. I didnt remember readings a stalling condition.

Just that it seems to be running out of fuel and sometimes take a while to crank.

[ChrisJ]

I am guessing you are not getting any trouble coeds either are ya?

The main thing that has me stuck on the switch is that when he messes with it then his fuel pressure goes up to 35...

Double check all the fuel lines to make sure they are secure and in good repair...

Try and see if we can fix this without you having to buy anything...

[Casper98GT]

dude, not to start a war but you tell me right now in a technical way how a inertia switch makes the fuel pressure regulated. I honestly wanna know. You tell me how a on/off switch makes fuel pressure jump.

[ChrisJ]

Originally Posted by Casper98GT dude, not to start a war but you tell me right now in a technical way how a inertia switch makes the fuel pressure regulated. I honestly wanna know. You tell me how a on/off switch makes fuel pressure jump.

I was talking about it stalling...I mis-read the earlier posts by him...I thought the car was stalling out...

I really have no clue how the inertia switch would have any way to fluctuate the pressure...The only way I could think of is if it is fluctuating the power to the fuel pump...And then that would effect the fuel pressure...

Im jsut trying to give ideas of what it could be...This used to be a big issue with the fox bodies...

[beheivjer]

if the inertia switch start to go on some vehicles it will allow the pump to work but not enough to run, i personally have had it happen on my sable wagon. its odd but it has happened thats why i ask.

[beheivjer]

i have a fuel pressure testor the connects to the fuel rail and then i have a autometter gauge in the car. It is a comp electrical gauge and the both read the same so i dont think i have a bad gauge.