From what I have read here, I need to get a fuel pressure guage, and screw it into the fuel rails? I know where the shrader valve thingie is, but im not sure what i need to do to test it.

Do i check it with the engine off? or both on and off? Do i drive around with it to see where the pressure is? Or should i just revv it in park?

Also, what PSI should it read?

Thanks guys!

 

Connect gauge to Schraeder valve, remove and cap the vacuum line that goes into the top of the fuel pressure regulator, and turn the key to the RUN position...don't start it yet. Ensure no fuel leaks are present. Having passed this condition, start the engine and read the gauge at idle.

Should be 39-48psi depending on what year your car is, assuming a stock fuel pressure regulator.

For troubleshooting a high-rpm dropoff, some people duct tape the gauge to the windshield so they can read it from inside the car and go for a thrash. This is normally done with the regulator vacuum line connected.

 

I agree. But I highly suggest you don't drive the car with the gauge hooked up its a fantastic way to kill yourself. Also be carefull about removeing it on a hot motor keep the end wrapped in towels as you are removeing it. I think I read your car was an 86' so GM's recommended fuel pressures 37 to 43 psi. So on that note I would be carefull about turning up the pressure. However it can have an extreme effect. My IROC ran 0to60 in 6.3 and the quarter in 14.48@100 w/ the stock pressure of 47psi but i ran 0to60 in 5.5 and the quarter in 14.1@103 by just bumping it up to 52psi buy a regulator if you don't have one but you don't have to crank it to get a big jump in power. 55psi is the max that tpis takes it to and that was with a later motor which had the stock pressure set higher from GM.

 

Yup, I said "some people" do it. Playing with pressurized fuel is inherently dangerous and should be done with caution.

 

There is nothing wrong with taping a gauge to the windshield. It's the people that run it in the car with them that are asking for trouble.