I have an 89 vortex motor in my wagon.

 

I noticed that it surges and loses power as it nears 5k rpm so i bought a narrowband Air fuel ratio gauge.

 

As i accelerate, it goes from rich and 3k rpm to full lean by about 4-4.5k rpm, (i wasnt game to rev it any more)

 

So i hooked up a fuel pressure gauge and noticed that at idle i had like 38psi and at cruise i had about 42psi. but on boost i have only 46psi.

 

Thats says to me that the fuel pressure cant keep up, as boost pressure raised by 7psi but the fuel pressure only raised by 4psi.

 

 

Anybody had a similar problem?

My fuel pump started making grinding noises the other day so ive bought a new pump

 

Will see how i go

Bump for an update

Replaced pump, still runs like crap and still makes noises.

 

So i swapped the Fuel pressure regulator and driveability is back. Not perfect so i tested fuel pressures and they are better, but im gonna get a malpassi ajustable 1:1 and use that.

 

The rubber diaphram in the stock one must go hard

Think you would be happier with a rising rate regulator like 1:1.5.

 

Easy/cheap way to boost pressure is to just restrict the return line with a hose clamp.

Make sure you post pics of the FPR when its installed. I need something to go off of for my wagon.