fuel pressure regulator ticking noise

[ofgofg]

Alright, so I have searched, this site, and Codsm,, to no avail. Also have googled about 10 different but similar topics but nothing helpful was found.

Heres the problem. I have a 95 talon tsi AWD, 5 speed. All stock, no mods at all, 63k original miles. Some problem huh? Anyway,, the fuel pressure regulator is making an annoying ticking sound. I can here it inside the cabin sometimes. I replaced it with a new one,, also replaced the FPR solenoid with a "used unknown cond" one,, and the ticking is perhaps a little quieter, but still there.

No, its not lifter tick, or crank walk, or spun bearing. I stethescoped it,, and definitely coming from the FPR. Just wondering,, what to check next,, or why it might tick. Too much pressure? Cloged return line? Cloged filter? Pressure leak somewhere? Along with the ticking,, it also has a hard start problem sometimes. Takes a while of cranking,, then fires. Not all the time,, mostly after sitting for around 9 hours in the cold.

Other than these,, the car runs great,, and once warmed up,, boosts smoothly and strong,, idles fine,, starts warm easily...

Coolant temp sensor?? O2 sensor?? Failing fuel pump?

 

[Calan]

Cloged return line? Cloged filter? Pressure leak somewhere? Failing fuel pump?

I would start with these. Minor changes in pressure can cause the spring and restrictor to "bounce" on the return seat in the regulator. It's also possible that the seal where the pump outlet joins the hangar is bad, causing pressure fluctuations.

 

[ofgofg]

Funny thing happened last night after work. It fired right up, no extended cranking. Hopefully, it will do it again tonight.

 

[Detail]

Are we sure this isn't the noise of the injectors firing?

 

[ofgofg]

Not injector noise. It actually sounds like an olde time electro mechanical fuel pump,, the kind you would use to supplement in an old ford truck. knockanockanockanockanocka.

I have a new theory. Pretty sure my coolant temp sensor is to blame for the hard start. So, it may also be to blame for the fuel system running at an incorrect pressure. Going to change the temp sensor,,, someday.