Fuel pressure regulation 95 tbi

[someotherguy]

I Looked up the pump on chevrolet website for 95 305 it's discontinued..they show a fuel line external pump...like you see on ebay for 29$ [the delco one is 167]

Most parts for these trucks you won't find from GM - long obsolete. But if you look up your application on Rockauto you'll find different part #'s based on which engine you choose. Pump manufacturers are aware it's not "one size fits all" on fuel pumps, but it's puzzling how the folks supplying a tank w/included pump don't give you the same options.

Richard

 

[PlayingWithTBI]

thought about putting in an adjustable kit they make but the location underneath tbi sucks you need a boy hand to turn the adjuster screw

You simply have to unscrew the 3 bolts holding the TB down, tilt it up and turn the screw. You're not going to be adjusting it frequently, you set it and forget it...

You must be registered for see images attach

Did you check for any blockage in your return line yet?

 

[Schurkey]

So I have a 95 silverado.

WHAT ENGINE??? 305?

I put snap on fuel pressure guage online and sure enough the pump is putting out around 30 psi.

HOW is the gauge connected? Is it installed "dead head", or is this in parallel with the injector/regulator? Is the engine RUNNING?

If the gauge is connected "dead head", the regulator is out of the circuit, you're seeing unregulated pump pressure which is going to be higher than the regulated pressure.

Ideally you wouldn't use a gauge intended for up to 100 psi on a system that only outputs 30 psi.

.according to chevy the correct pressure is 15 psi.

I thought it was 9--13. Most guys want to be at the upper end of spec.

the factory regulator in the tbi may not be able to return this much excess to the tank.

Only if the return plumbing is restricted, or the fuel pump is some wild aftermarket high-volume pump. High pressure doesn't mean squat. High volume--IF the volume is more than the return plumbing can accommodate--could be a problem. It's also unlikely that your pump produces that much volume.

My '88 K1500 5.7L has a high-pressure pump, and it's worked flawlessly with the original style regulator and plumbing for decades.

so two ways to fix.....1] fuel pressure regulator....or 2] drop tank and put in pump with 15 psi.

The stock TBI pump probably puts out 17-ish psi. The pump must be capable of more pressure than the regulator is set at.

The pump could output 300 psi, but unless there's a restriction in the return line, the regulator will maintain whatever it's set to.

First Guess: Someone crammed a higher-pressure spring in that regulator, or the regulator is from a big-block TBI that uses higher pressure.

Second Guess: You've got kinked tubing somewhere on the return side.

Third Guess: Your procedure for measuring pressure is faulty.

does anyone know of a fuel pressure regulator that will drop into 15 psi?

The OEM regulator IN GOOD CONDITION will work just fine--if the return plumbing isn't restricted.

does an y one know where to get an in tank fuel pump that puts out 15psi?

Mistake in logic. You don't need a lower-pressure pump. You need to verify the function of the regulator you already have, and you need to assure that the return plumbing--hoses, metal or plastic tubing, etc--isn't kinked or otherwise restricted.

I want to stop the excess before it gets to the factory regulator on the theory that it was never designed to regulate double the oem pressure.

Wrong theory.