Dave2500

Hello
Maybe someone has some ideas,
i have a 97 TA lt1

it is starting real hard, but when it is running it doesnt miss a beat

so, i bought a fuel pressure tester and i think i may have found the problem area.

when you cycle the pump it goes to about 43 psi, but as soon as it goes off to start the car it INSTANTLY drops to 0 and when cranking slowly comes up to like 10, but when it starts its at 43 again

does it sound like the fuel pump or the regulator?
Thanks
Dave

hrcslam

To find out if it's the pump or regulator you need to block of the return line from the regulator to the tank. If it still drops its the pump check ball, if not it's the regulator.

Paul Bell

iTrader: (9)

While I'm sure this is obvious.....have you changed the fuel filter?

ThoR294

iTrader: (6)

fuel filter doesn't prevent bleed back of pressure... its either the 1way valve in the pump or fuel pressure regulator. With the pressure dropping that fast, I have a feeling its the 1 way valve on the pump

Dave2500

Hello
thanks for the help
i put a new pump in and it starts right up the pump must of been bad

now the pressure goes down to 0 after like 20 seconds when it isnt running
does that sound normal

ThoR294

iTrader: (6)

The check valve is part of the fuel pump... so you put a new pump in, and you still have the issue with pressure dropping?

Next step would be, like said before, is block the return line off the regulator and see what happens... If it still happens, you might have gotten a bad check valve in the new pump

Dave2500

thanks for the reply

it is not dropping as fast as it would before (and it runs good now)

so i am thinking of just doing the pressure regulator like this one here:
https://www.texas-speed.com/p-2108-n...regulator.aspx

i will also get a gauge to keep a eye on it

do you think that regulator is good?
you dont think injectors can leak that fast do you?\

Thanks

nomoneyz

iTrader: (15)

You've been given advice on how to diagnose your car so you don't throw parts at it. Why don't you do what was suggested? That way you'll know what is wrong. No need for an aftermarket regulator and the work to hook it up to your fuel rail. Test yours and if it bad get a new one.

ThoR294

iTrader: (6)

Injector will not leak that fast... if it did, you'd be running like garbage lol and washing down cylinder wall(s). Do the regulator test first unless you just wanna spend money

nitrous2fast

iTrader: (2)

A bad pump check ball isn't going to reduce the ability of the pump to supply fuel. IF the regulator is in good and working order then leave it as it is.

ThoR294

iTrader: (6)

He said it runs fine but when he turns the key off he loses pressure

nitrous2fast

iTrader: (2)

The car really doesn't need fuel pressure when the key is off.

ThoR294

iTrader: (6)

You car needs to hold fuel pressure after its turned off for roughly 30 min. It slowly goes down... Not immediately after the pump stops

SS RRR

iTrader: (2)

How important is it for the fuel system to hold pressure after the engine is off if the pump is proven to hold good fuel pressure throughout the RPM band? Mine has always immediately started to bleed off three pumps later. Injectors do not leak, either. No leaks in fuel system so I've never worried about it.

ThoR294

iTrader: (6)

It allows the car to start better. Imagine turning your key on and getting settled in then trying to start your engine. If your fuel pressure is 0 you're going to have a very rough time lol.

nitrous2fast

iTrader: (2)

The fuel pump primes the fuel system when you turn the key to on... this is why I tell people to cycle the key to on and off a few times after they have ran out of gas and gotten more.