Vacuum leaks: should EGR solenoid and FPR hold vacuum?


Feb 28, 2003
In my search for a lowish boost Kr problem, I decided to make sure I have no big vacuum leaks.

I 've been replacing all the vacuum hoses and using a Mityvac to test for leaks. I was surprised that hooking the Mityvac to a short piece of hose, then to the vacuum nipple on my Bosch adjustable fuel pressure regulator, it didn't hold vacuum well at all. The needle moved when I applied vacuum but sank back to zero within a second or so. Is this normal?

Also the EGR solenoid. Applying vacuum to the larger hose that goes into the solenoid, it leaked audibly. Car was off at the time. Is this normal? It sounds like it's an open system which of course doesn't sound right. Perhaps it's a closed system when power is applied? Also does anyone know if you can get the little tiny air filter that goes under the round plastic cap on the solenoid? I somehow put my stupid finger into mine tearing it a bit.

They both sound like they are toast, they should hold vacuum. The regulator I am almost sure should hold, the egr should for sure, one test for a bad egr is to push up on the diaphram and hold finger over vacuum inlet when you let go of diaphram, it should hold.

there are vendors that sell egr selenoid filters, can't remember which ones off the top of my head, too early in the morning.
Thanks for the reply. To be honest I'm not sure how the EGR solenoid works except that I suppose it likely decides when to apply engine vacuum to the EGR valve. The fact that it seems to have a little air filter suggests to me that it's supposed to suck air at times. I'm gonna read up on how this works and maybe test it with the car running to see if applying voltage to the solenoid closes off the system and makes it hold vacuum. The EGR itself holds vacuum so that seeks to be functional.

Yeah, at the very least the FPR sounds like it might be toast. I'm gonna see if I can dig up the stocker until I can order a new one.
I've been through this and the FPR should definitely hold vacuum. If not then the FPR should be replaced as I've seen it where the fuel will leak into the vacuum chamber of the FPR because the diaphram is defective.
Before trashing the FPR thought I'd open it up. The mating surface where the top of the housing and the bottom meet looked a bit tweaked and the rubber o-ring looked a bit damaged. I put some RTV and we'll see if it holds pressure.