how to tell if fpr is good/bad

[gmmuscle]

Just installed fuel pressure gauge, boost/vac gauge and have scanmaster. FPR is stock but reading 40-42 at idle. My Kirban book says stock FPR is 28 at idle? Boost and FP rise 1-1 under boost. When I pull the vac line from FPR the pressure goes up 4-5 lbs.

I know the fuel pump is going bad as it is really loud, and after driving, it has a bad surge sound that cooresponds to 4 inch fluctuation of vacuum and about 1 lb on fuel pressure gauge. Fuel pressure also sometimes drops to 36 at idle.

Trying to tune, too many other issues/ tests am performing, data from scanmaster-but first need an answer to this question.

Carl

 

[84BuickGNYorkPA]

You all most have to update your ECM (computer) chip from stock, because of the change in fuel among other factors, as in advancements in chip technology.
And as far as I know, they each have there own fuel pressure at idle specifications, for example Turbo Tweak, ask us to start at 42lbs pressure with the vacuum line off the fuel pressure regulator. Saying that you may want to rethink having a stock fuel pressure regulator on the car. Not telling you what to do, just saying what most of us have done.
I would say from what you are telling us, about the fuel pressure, the pump is on the fritz... And again most of us go with a aftermarket pump and hot wire kit for the fuel pump... hope this helps in some way.
Edit: ooops I see you have a turbo tweak chip, you will need a adjustable regulator in that case...
To answer your question on how to tell if a fpr is bad, the way I do it, I have two adjustable regulators (I have almost 2 of everything on the car) and swap them out to compare pressure readings to each other, usually if they go bad, they have a leak, from what I read.

Chuck

 

[gmmuscle]

I'm a little premature on the tt chip (listed in my sig file). It will be here in a few days.

 

[84BuickGNYorkPA]

I'm a little premature on the tt chip (listed in my sig file). It will be here in a few days.

That's good it's on it's way, fuel pump failure is pretty common, I keep a spare one all the time. You might as well figure on getting a good one and a billet adjustable regulator.... and a hot wire kit if you don't have one already. The stock pump barely has enough muscle to feed a stock motor, any little performance upgrade and you'll need more dependable fuel.

Chuck