I installed a fuel pressure regulator. I do not know exactly how to use it. I put the guage on and the fuel pressure jumps back and forward from 40 to 60 psi when the car is started.

I took my car to a dealership and they hooked up a guage to it and it was steady. I baught a new guage and it is still doing the same thing.

What could cause the fuel pressure to do that?

I didnt disconnect the hose at all when i changed the psi.

so i could use some instructions on how to use and where to set it at for the best performance.

And why the fuel pressure is jumping so much.

 

[B]


Adjust it with the vacumm line disconnected. Trial and error. Every car is different

Another faulty gauge? What brand?

 

The one i thaught my g/f broke was from crane cams.

The new one i baught is from auto zone. so....

What vacuum to i unplug. I know you have to release the pressure, and the guage a button on it to release it.

I guess ill try it unplugging the vacuum that goes to the breaks.
Change it, then plug it back up.

I guess your right with the trial and error.

what is the stock fuel pressure for my car?

were should i set it at?

would getting a aftermarcket fuel pump help, maybe a fuel rail also?

coul dthe spark plugs not getting a good spark cause it to jump like that?

thanks for the help, very thankful.

 

u have to unplug the vac line that runs to the afpr, and ajust it to that pressure, that would be ur wot pressure,
i think stock psi for ur 350 is 43, i have an afpr on mine and i have it set for 47 wot and at idle its about 38, most ppl set it to where they get the most seat of the pants feel, but do not set it over 50 ur u will be replacing ur pump soon if its a stock one,
not sure why its jumping around on u like that, hopefully u just got a couple of bad gauges, was it running good before u installed the afpr? spark plug fireing has nothing to do with the fuel pressure it would spray out of the injector long before it gets spark so its not jumping cause of poor spark

 

i know what what you ment on the unplugging the vacuum. I was a little confused.

Well, i just finished messing with it and with just the key on i set it at 42 psi.

the guage still jumps back and foward when i start it. i tryed both of my gauges and they both do the same exact thing so i dont think there broke.

does an adjustable fuel pressure make a differance in performance? i've heard they dnt do anything and then i have heard they can make a big differance?

 

I agree with billyhoss, as I had 2 Autometer gauges do that annoying flicker. Probably another bad gauge.

 

they are supose to spray out better at a higher pressure to get better atomizaion(sp) so it can mix with the air better, u should set it with the car running and the vac line off, not with just the key on, while its runnign does it flicker all the time or just on start up?

 

it flickers all the time when the car is started up.

I'll try adjusting it with the car runnning.