FPR help

[Breeze77z]

Ok, my '77 280z's FPR is dying, so i called summit and ordered an adjustable FPR from MSD (PN-2220) hoping it would work because it didn't specify if it had a bypass or not. Well, it just had two ports, so no bypass (right?). I called them, told them what i needed and that i could get a bosch one from Top-end to work on my car, so i shouldn't need the Aeromotive one that he recommended (twice the price), but he said they didn't carry bosch, well the MSD one i just sent back was bosch so he looked into it a little harder and told me that MSD PN-2222 had a bypass and was boost referenced too. Well, i got that today, and it has the same two ports, plus a little one coming out of the bottom, so i'm thinking, no, still no bypass, just a vacuum line now. Am i wrong to think that there has to be three ports (inlet, outlet, bypass)? and am i wrong that what i have won't work? I tried bosch's webpage, but they don't even mention FPR's, i tried MSD's and they have crap for info on both FPRs, i tried JWT because i read they sell a bosch adjustable unit that some people on here are using on their early Zs and i didn't even find early Zs listed for part selection.

 

I'm at a loss and getting frustrated, so any help would be great. Thanks in advance.

Pat.

[Guest Ian turbo240]

First, I'd like to know how you found out that your FPR is bad. Have you checked fuel pressures? Regardless, just about any FPR designed for fuel injection will work as long as the pressure setting is adjustable. It needs to have an inlet, outlet and vacuum port. That is all. The FPR acts like a dam on a lake. It just stores fuel pressure behind it until the set pressure is met and the releases enough to hold that pressure. There are 3 ports on the Z's FPR because the two horizontal ones act as one inlet. Those are there just so that both sides of the fuel rail are fed with fuel. The bottom one is the return. Hope that helps.

 

Ian

[Breeze77z]

Good point, i'm assuming (hoping) its the FPR. It runs rich, even before the Big Bore Throttle Body was installed, but not enough to foul plugs. It does shoot flame out of the exhaust on full-off throttle decceleration though (still working on a pic or mpeg), but i think my header leak helps that because it never did that until the leak grew more pronounced (read: obnoxious). Either way i'd like an adjustable FPR to maybe help reduce the richness of the air/fuel mixture, but the lack of a port was throwing me off. http://www.msdignition.com/fuel/2222_big.jpg

Here is what i have. Any thoughts on how to install it? I could just put a hose to bridge the gap the old FPR would leave and mount this somewhere close to where the feed line and return line both run, right?

ok, thank you for the info and clearing up my confusion.

Pat.

[Guest Ian turbo240]

In order to know for sure that the FPR is bad, you need to check the fuel pressure. In 10 years of working on F/I'd Zcars, I've never seen a bad FPR. That doesn't mean it can't happen, I just doubt that that is your problem. However, the one in the pic you provided will work. You just need to tee it off of the fuel rail. As for your rich condition, start by checking connections to the coolant temp sensor. Make sure the CTS signal is getting to the computer. You can use an OHM meter for this. If the CTS is good and the signal is getting to the ECU, then start to suspect the AFM or FPR. Good luck!

 

Ian