pcolt94

I'm in the C5 forum because I have a LS1 question.

Working on a friend's C4 with a LS1 engine. It was installed by an engine shop with lots of changes to the car and frame. My question is in regard to the fuel pressure regular (FPR).

The FPR is installed on the right side rear and top of engine with a fuel pressure gauge along side of it. Starts fine and runs with a pressure of 60 psi. But the pressure never changes when throttle is opened. I noticed the vacuum port is capped off with no input vacuum to it.

I did put vacuum to the FPR and it did vary the fuel pressure so it does work. It's just not hooked up so the fuel pressure remains at 60 psi.

Is this a normal set up for a LS1 where there's no vacuum line to the manifold?

Thanks for the input.

lionelhutz

Yes, no vacuum on the regulator.

pcolt94

Thanks for the info.

I thought the engine shop took a short cut or screwed it up. Would not have been my first guess for the answer.

lionelhutz

Well, my car has a little hose in it but it goes to the air breather where there is no vacuum. Plugging it may not be the best idea since that side needs to have an atmospheric reference.

pcolt94

Point taken. Florida pretty flat not much change on atmospheric pressure here. Also I don’t think that little plastic cap seals that well.