: Clogged vacuum port to fuel pressure regulator

09-27-07, 08:13 AM
(This post is not about checking for a bad FPR [fuel pressure regulator]. It is about checking for an extremely clogged vacuum port in the manifold. This is something totally different than checking the FPR. It is also something that could be easily overlooked.)

I just thought I'd let everyone know about a problem that I had that could be common on other cars. I pulled the vac line off of the FPR (fuel pressure reg) to check for gas coming out of it. No gas (good), but I also noticed there was no vacuum in the line either. I pulled the short little vacuum line off the intake and it was clear. I tried to poke a wire through the intake manifold nipple and couldn't even force it though. I finally took the intake completely off to see what was going on. I took the throttle body off and found a 1/4 inch of built up nasty carbon all over the back of the throttle plate and inside the intake. This also covered the vacuum port for the fuel pressure regulator. It actually took a drill to get it opened up, even after I scraped all the carbon off the inside!

This vacuum line is important for proper fuel mixture. If it is clogged, fuel mileage could suffer and the engine could run lean or rich causing other problems. My car ran better instantly after fixing this.