Discussion Starter · #1 ·
Okay, my CJ with MPFI had been idle badly. It would drop to almost dying then come back up the back down. If I applied some gas quickly it would die. This would go away once it warmed up. So while cleaning the engine to get ready to fix that lovely leaky vavle cover I noticed a rubber hose the ran from a port on the intake manifold had come off of somewhere and was just lying there. I look around and see a round silver colored round thing with a nipple coming our of the center. This is on the end of the fuel rail. I believe this is the fuel pressure regulator and the rubber hose is vacuum. I reconnected it and my baby runs fine now. Even seems to have better acceleration.So, if my assumptions are correct, what does the vacuum do here?