Hello and thank you for any info you can give me. I have a 1998 gmc jimmy with 4.3 vortec vin w. I replaced egr,iac,plugs,wires,cap,rotor,tps, I noticed the new spider injection the pressure sending unit looks like it has a vac line or should have one. when I took it off there was no line. does this work off the vac of the intake manifold? There is a sensor on the top of the plastic plenum that says pressure sensor is this the fuel pressure? I have a problem of the truck runs great idles smooth drives smooth but when I come to a stop it stays at 1000rpm and right before I come to a complete stop it dies down to 800 or 600 rpm idles fine. Tap the gas and it goes right back to 1000 when rolling. this is the only problem with this truck that has me totaly baffled. Thanks again for any help.

The 4.3L does not have a fuel pressure sensor. Where is the sensor you're refering to? The EVAP solenoid and the MAP sensor are both on the passenger side of the plenum. If you post the color of the wires that are connected to it, that will help us identify what it is.