hello guys,

i have my comptech SC with AC kit installed for 2 months. recently, i hear some ZZZZ sound from the car. normally, when i use the air condition for more than 1 hour then u can hear that sound, but if u park the car for a night, then the sound should disappear when i drive it in the morning. same case, i use the air condition more than 1 hour it appears again. i also can hear this sound when i turn the key to connect with the battery( before i push the start putton). i can hear it for 1-2 secs. after the gas gauage meter fully loaded the sound disappear.

by the way, if i don't use the air condition during the driving, nothing will happen. there is not problem when i use the CD player.

i go to a car shop and let some guys listen to it, they say it sounds like the electronic current, but they don't know where to look at it and they say it is not a big deal. i do not want my car with any problem, so what should i do? do u guys have the same experience? how can i slove this problem?

 

Sound could be your upgraded fuel pump. Can't see why that's air conditioner dependent though. Mine makes a whining noise every once in a while. If not that, could be a grounding issue. Does the sound go away when you turn the stereo off?

 

i am sure the sound is different from the fuel pump. i can hear the fuel pump sound and that electronic current sound together when i use the air condition more than 1 hour. when i turn on(off) the radio, it doesn't change. when i change the fan level, the sound will change a 0.5 sec. then it is still on.

i think the air condition works fine. the problem must be from the wiring. but the sound just comes out when i use the air conditon for long. the car shop mechanics tell me this sound seems like electronic current , but they don't know where to look at it.

 

Definately your fuel pump....it's normal. As for your air conditioning issue..... We went on a trip to Las Vegas recently and ran the A/C with 2 SC'd cars....both of us mentioned the humming of the fuel pump.

 

but i can hear that electronic current sound and the fuel pump sound at the same time. The sound is different. is that still the fuel pump?

 

It could be interference from the white aftercooler wire that comes through the firewall.

Next time you hear the noise, pop the trunk and see if it gets louder. From the intermittent way you are describing it to be, I also think it is the Walbro, which tends to whine under very inconsistent conditions.

 

FUEL PUMP!!!