I noticed the other day when I turn my key to on (engine not running) I hear the fuel pump fire up (nothing new) but I noticed another noise coming from the engine bay. I had someone turn the key on and off a few times and noticed it was comming from the intake manifold area. The only thing there to make that type of noise is the fuel rails. I don't seem to remember ever noticing this before but is it normal? If anyone wants to hear it I did take a video that I can upload to my website if needed.

Thanks

Dan

 

You sure it's not the airpump turning on?

 

I have the same noise and I dont have an airpump. Ive always thought it was normal, if not it be interesting to see what it could be.

 

the only times I have heard that noise is when my fuel rails were completely empty/unpressurized.. as in when I have opened the system or let the car sit for a long time.. like the three weeks it was down during my six speed swap...

could be leaky injectors, a bad check valve, or nothing at all... I would say if all runs well and it starts right up.. don't worry.. worrying would be like jumping at every creak a plane makes before takeoff..

 

Hmmmm I wonder if this could possibly in some way be the cause of my upper RPM miss if it isnt normal.

 

check you fuel pressure.. turn on the ignition and let your pump prime the system and then watch the gauge.. it should stay around 40.. when a buddy of mine had a bad check valve it would prime to 45 and then all the pressure would bleed off to zero in a few seconds.. when he would turn it over you could watch the pressure slowly build until there was enough to fire up the car..

a miss usually points to the standard coil, opti, wires, plug gap scenario though...

 

The car runs just fine I just never remember noticing this noise before. It'll make the noise if the key is turned off for more than 10 seconds and then turned back on. If i turn it off and on real quick it doesn't do it.

Edit: here's the link to the video with the noise.

http://www.dan1701z.com/videos/carnoise.AVI

 

Dan, mine sounds the same way.

Ill check the fuel pressure tommorow...

 

Sounds like you have a sick bird in your car! J/K.

It has to be something in the fuel system. It seems to go away as soon as the fuel pump stops priming. Perhaps the fuel pressure regulator is leaking fuel..??

Does the sound continue after the engine fires?

Your best bet is to do as mentioned before and get the fuel pressure tested. I bought a gauge a year ago and has helped me diagnose a lot.

 

It is pretty normal to hear some noise when the lines are pressurizing (unless they have been pressurized real recently).