i just got my s/c installed like last weekend, and when i start it up early in the morning b4 i leave for work (6:45am) i let it warm up for about 15 min or so b4 i start driving.

when i start it idles really low (about 450-500rpm) then it'll idle high (about 1200-1300rpm) and it will keep going back and forth.....also when it idles low, the motor seems to almost want to stall out....you know it makes that knocking sound when the engine bogs really low.

when i start moving, however, the rough idle and the low idle go away, and it idles and runs great.

is this normal? or should I take it back to the dealer?

Thanks everyone

 

possible vacuum leak.

also you dont need to warm up your car for so long. i usually let it warm up for like about 3 minutes, just make sure you dont hit boost before normal operating temperatures...

 

ill have to go and check, ill trace all my lines back to see. are there any major problem areas that i should check first?

Thanks

 

if you had the dealer install it then have them check it...

 

It's normal bro. I know it sound crazy but it's OK

 

I dunno 450 rpm sounds really low, my s/c did this, this morning when it was a mere 58 degrees out failed to start after 4 cranks (it started then fumbled then died), and now its back in the shop for the 9th time in 11 days.. But the revving up to like 1-2k is normal.

 

thats kool, i thought that somthing was messed up with the unit, or that somthing went rong with the install. Thanks for all the help.

it hasnt failed to start yet (knock on wood), but if it does i will def. be taking it in and having it looked at.

Thanks again guys

 

I had this exact same problem right after the dealership installed my supercharger. When I picked it up,all the techs had left for the night,so I brought it back the next morning. Turns out one of the vacuum hoses next to the throttle body blew off. Perfect idle after that.