How do you replace the fuel pressure regulator on a Chevrolet astro van?

What kind of Fuel Injection system do you have? Do you have a fuel rail? If you have a fuel rail - it is at the tip of the fuel rail (front of the engine). There are two tiny bolts that secure the fuel reg to the base of the front fuel rail (bolts with tiny nuts on the inside - so be careful about losing them around the heat shield that is on top of the intake manifold).

Once you have freed the fuel reg. from the base of the fuel rail, it will come off of the fuel rail. Remember, to de-pressurize the fuel system (there is a cap nut on the side of the rail, take the cap off and de-pressurize). Sometimes, you do not have to de-pressurize (on the rail side of the fuel reg. sometimes that o-ring fails, and that willautomatically depressurize the system). You have to depressurize, or prepare to take a quick mini shower in gasoline.

Ok, the other side of the fuel reg. - not the fuel rail side, but the other side. You should see a VACUUM WIRE BLOCK JUNCTION. Fuel reg has a vac hose that plugs into a manifold fitting - disconnect it and lay it aside. Pull that VACUUM WIRE BLOCK JUNCTION directly upwards and it will come off (don't break it!). Under that juction block is a bolt - loosen it. The retaining clip for the junction block - remove it, and the wire harness retaining ring (flat pice of rounded thin gage stock meant to hold the wire harness on the front side of the engine manifold. Most importantly, remove the same style retaining clamp for the fuel line. Now, you can work on the Fuel reg. - it is freed up, and should wiggle around freely although it is still attached to the hose. I goota get back to work - this should be easy from here on out - reverse the procedure for installation and send $20.00 to Wulfmun! Just kiddin - good luck! Wulfmun.