Chevy & GMC Vans

Hey there,

I have a fuel pump question.

A couple of years ago I had SPR Performance Mod my TBI, it was suggested that I also up the pressure with a new pump. I also adjusted the regulator to allow for more pressure. That new pump has now failed. As we all know, it's a major pain to replace a fuel pump, so I put in a new EP386, the OE stock pump.

Well, everything works, but the van no longer gets up and goes like it used to. Even after two years I was still surprised every time I started from a stop and it was also enjoyable to feel the power range as I accelerated to the next gear. The surprise and feeling are gone.

What am I doing wrong?

I would start with taking a fuel pressure reading.

How does one go about checking fuel pressure?

You attach a pressure gauge to the fuel rail.
Loner62quiet @ fuel pressure
Autozone should have loaners.

Fuel rail? I've got a 1987 with TBI, no fuel rail.

Properly relieve the fuel system pressure.
If necessary for access, remove the air cleaner assembly and plug the vacuum port(s).
Disconnect the flexible fuel supply line, located in the engine compartment between the fuel filter and throttle body.
Install a fuel pressure gauge, such as J-29658 or equivalent, in-line between the fuel filter and throttle body unit (between the steel line and flexible hose). If necessary use an adapter or Tee fitting in order to connect the gauge and complete the fuel circuit.
A Tee fitting may be fabricated for this purpose. Depending on the fuel pressure gauge, short lengths of steel tubing, appropriately sized flare nuts and a flare nut adapter may be used.
If the engine will run, start the engine and allow it to run at normal idle speed. The fuel pressure should be 9-13 psi (62-90 kPa).
If the engine does not run, turn the ignition ON, but do not attempt to start the engine. Listen for the fuel pump to run. Within 2 seconds of turning the ignition ON, pressure should be 9-13 psi (62-90 kPa). If necessary, cycle the ignition OFF, then ON again, in order to build up system pressure.
If the fuel pump did not run or system pressure did not reach specification, locate the fuel pump test connector. The test connector is usually found on the driver's side of the engine compartment (on or near the fender), with a single wire (usually red) leading from the relay to the connector. Using a jumper wire, apply battery voltage to the test connector in order to energize and run the fuel pump. The pump should run and produce fuel pressure of 9-13 psi (62-90 kPa). If the pump does not run, check the relay and fuel pump wiring.

OK, Thanks