Wanted to share this here to get the information out there since I know this issue frustrated the living hell out of me for weeks and no amount of tuning or creative thinking at the time could I figure this out. I eventually removed the adjustable FPR kit and went back to the stock unit.

There is a long running but apparently little spoken of issue of lean conditions at low RPM typically between 2000 to 3000 RPM's when using an aftermarket fuel rail and aftermarket fuel pressure regulators on the X. I personally was affected by this when I installed an AMS fuel rail along with an AMS AFPR kit. It was so bad my car would buck and almost stall if I put it in 5th gear and tried to go slightly uphill such as on on ramp starting at 2000rpms. It happened from low load vacuum to a few PSI of boost. The only way around was aftermarket rail and stock regulator (I can confirm) or aftermarket regulator and stock rail (I never tried this route).

With that said it was speculated that a Fuel Pulse Dampener (FPD) as seen on various manufacture cars may help and/or solve this issue such as the one offered on the Radium fuel rail:

http://www.radiumauto.com/Fuel-Rail-...on-X-P394.aspx

A user going by the name "Boostinhuey" on another forum took the initiative to modify his AMS rail using a FPD from Radium and had great results. This made me take the plunge and modify my AMS rail the same way so the AMS AFPR would no longer be a conversation piece sitting on a shelf.

So last night I got to work on the fuel rail modification and I can happily report the FPD completely resolved the lean issue. I tried every way I could to induce the issue including running 5th from 1500 RPM till 3500 RPM not once did the car remotely go lean. Now after a day of driving the car to and from work and around during lunch break I can further confirm the issue has been completely resolved.

You need to drill & then tap a 3/8" NPT hole in the bottom of the rail between injector #2 and #3 as shown in the pictures below.

Here is a direct link to just the FPD:

http://www.radiumauto.com/Fuel-Injec...mper-P300.aspx

Enjoy.

 

Nice! I've been wondering about this so I'm glad someone took the plunge.

 

Interesting find! Maybe this would help those of us with erratic idle leanness with big injectors. Putting the car in open loop helped some on this but it's still pretty erratic for me. I'm on the stock rail. Wonder if there's a way to add a damper.

 

I'm going to do this to my AMS rail as soon as the FPD comes in. My car sputters 2000-2500 and couldnt figure it out.

Thank You

 

Thanks for the info. very usefull

 

http://www.radiumauto.com/Fuel-Pulse-Damper-Kit-P606.aspx

 

Has anybody else tried this? My car still has erratic idle issues. I'm Going to try it but the site is down.