Tapping in the fuel rail

[tazgn]

I asked this a while ago, but didn't get any answers. I have a rather exotic setup. I have CAS's sheetmetal intake which comes with the custom fuel rails. Also 83# injectors and FAST DFI. The rest of the stuff is in my sig. My problem is a rather LOUD tapping sound from the fuel rail on the passenger side. I can feel the tap as well most predominately in the supply line and fuel rail on the passenger side. I can't feel any "tap" anywhere else on the drivers side (i.e. intake, injectors, valve covers, exhaust, cam sensor, water pump, tanny, etc.). I've tried disconnecting each injector one at a time on that side with the car running with no change. I can also feel the tap in the supply fuel line all the way back to the tank. It has me stumped. It gets louder as the car heats up to the point where you can here it echoing of cars next to me on the road. Any ideas at all???? Any ideas on what I can try to do to find the culprit? My fuel system consists of a -10AN line from the tank to a 'Y' block. Then 2 -8AN lines to each rail. Then out of the back of each rail with 1 -6AN line on each rail to the FPR. Then a short -6AN line from the regulator to a -6 to -10 adapter to a -10 line to the tank. My fuel pressure is very steady while running too. I'm stumped, but when it's hot people must think it's about to fall apart.

Derrick

 

[REDS HOT AIR]

that is a wierd one...only thing that went thru my mind was a injecter using the rail as anamplifier but you unplged then with no change

just for giggles have you pulled plug wires one at a time to the cylinders on that side?

sounds like a nasty lil 3.8 you got there

 

[tazgn]

Yep, I have tried pulling the plug wires one at a time as well. Same damn tapping. I've also disconnected 2 injectors at a time and the tap was still there even though the motor had a hard time running. I've even had it running with all three injectors on that side disconnected, but it was hard to tell if the tapping was there or not as my attention went more to trying to keep the motor running (but I think the tapping went down quite a bit). Oh, I forgot to mention that it does increase it's frequency with RPM. I've thought about switching sides the injectors are on (put drivers side in the passenger side and vice-versa), but it's a big job with the CAS setup. It almost sounds like a lifter, but I can't feel it anywhere (even the rockers shaft) but in that fuel rail and supply line (and much fainter in the line to the FPR).

Derrick

 

[Black Car]

Have you pulled the valve covers to see if there are any marks where something could be hitting? I am just suggesting a possibility.
I understand how this can drive you crazy.

Gary

 

[REDS HOT AIR]

wierd for sure

feed line dont happen to be laying on the cam sesor or anypart of the timing cover