the following.
92 DX hatch
D16a6 w/ vtec z6 tranny
Walbro255 intank
B&M fpr (and gauge)

Before I got the FPR I installed a Stage3 PYR race cam with 270/280 duration. This isnt a streetable cam, doesnt idle + low vacumme so brakes arnt as great either... anyways. After installing I started getting check engine codes for fuel pressure. The B&M gauge is reading 65-67PSI at idle and WOT on the 3 different OEM fpr's I have so I put the B&M FPR on and turned it completely down. Now its at 57-60psi all the time but still running way too rich. How can a cam cause this? or could it be the fuel pump? I didnt have the problem before the cam but I dont see where a cam would effect fuel pressure. I know it could be tricking the ECU from such low vaccum thinkin it is under WOT. but why around 60psi? any clue? thanks to any who can help me find the problem.

Oh yeah, any of you have Walbros as daily's? any fuel pressure changes?

 

I have a Walbro and B&M on my daily and yes the pressure is a little high, at least when I had the guage installed. My pressure was usually between 45-50 somewhere around in there.

Have you tried drilling the little hole in the regulator to get the pressure lower?

 

No I havent yet, But i'll try that. Any other tips you know of? thanks for the reply

 

You said the Cam isn't streetable. You also said that it doesn't idle well and has low vacuum.. You know this because your brakes don't work too well..

Well if you know that you have low vacuum @ idle and you know that you have a vacuum line to your Fuel Pressure Regulator (FPR), you've pretty much solved your problem..

I'm pretty sure your FPR has a vacuum line to it.. Doesn't all Honda's, I might be wrong.

But if it does have a vacuum line to it, this is how your FPR is suppose to work.. The FPR uses the vaccum to assist in controlling fuel pressure. Low vacuum, not enough assist to FPR and thus FPR restricts and raises fuel pressure.. High vacuum, FPR doesn't restrict as much and lowers fuel pressure.

In short, the low vacuum caused by your camshaft isn't enough to assist your FPR to lower the fuel pressure.

Hope some of this helps..

 

read this:
http://www.theoldone.com/articles/regulator/

 

I know this. I was just making sure about the pump. I'm removing the pump this weekend for a stock one. thanks again for all your help.