I have 680cc and aem fuel rail and aem fuel pressure regulator.. I noticed my idle was rough I check the fuel pressure gauge and it was shaky..I tapped on it with a wrench and it held steady and idle was better..I opened up the fpr and the diaphram is like new.. Its the newer design..Maybe the spring is stickin? help!

 

So your problem went away?

 

no sir....after 3-4 hrs...fuel pressure gauge is shaky...tap on the fpr steady again lol

 

Swap it with a stock FPR and see what happens

 

I wouldn't worry about it. some gauges need a dampner or they will shake it.

 

well after switching to stock oem fpr...fuel pressure guage is steady... wondering if i stay with stock fpr will it effect my tune??? i was tuned with base pressure @ 50psi...

 

Pretty sure it will seeing that stock base pressure is 43psi