I was wondering if it was normal for the engine idle to become lower after the supercharger install?

I'm idling around 500-525rpm warm. On occassions at a traffic light it would drop to 450 and the car would shake but not stall. The car that came with the supercharger said the car would idle rougher but is this what I should be expecting?

I'm going to be bringing my car into a dealer to look into the battery warning light coming on while driving. I wonder if it is related?

 

I used to have a supercharger and when my car was fully warmed up, the idle was the same as stock. My idle is still the same as stock even with my turbo. So something is def not right.

I doubt it has to do with the battery because you can disconnect and remove the battery from your car if you want while the car is running and it will still run.

 

The car will take some time to learn the new fuel maps being presented to it. It will calm down and hold a steady idle after a bit.

 

i had the sme problem and it didnt go away after 2 week. i took some throttle body cleaner and sprayed it on a rag and cleaned my tb and it then worked fine

 

x2!!!!!!!! to that! I did the same and it fixed my problem. Mine wasnt idleing at all. it would just die if I let off the gas when i came to a stop.

 

Shortly after mine was installed, I got the same warning...took it back to the dealer and it turned out that the alternator was not tightened down after the install. I'm not sure if these issues are related, though...

 

also check for a vacuum leak...my vacuum line was left uncapped after my tune and that is exactly what happened. Went to autozone, bought a cap, and capped it and it ran fine

 

clean the MAF sensor. buy some MAF sensor cleaner from a car store and clean it up. you should notice a big difference. hope this helps.

 

x3!!!! i had the same problem and dealer cleaned out my throttle body. car doesnt die but occasional rough idle.

 

I brought it into the dealership today.

I told them the symtoms and they took it in the back for diagnosing and I went off to work.

The tech tested the cranking and charging systems and determined that I had a bad battery. (odd its not even 2yrs old) They also found that my cargo light had been disconnected. (normal after a super charger installation?)

Anyways, they replaced the battery under warranty and said they couldn't reproduce the low idle. I didn't notice it either on my way home. I'll find out if it is truly fixed tomorrow on my commute to work. The 2 mile drive home and cold weather might not be enough to warm the engine up enough have a rough idle.

BTW - is there a good throttle body cleaning guide for the tC? I couldn't seem to find any tC specific ones around.

 

i went to a auto parts store i read the label. some said sont use on turbo or s/c cars. the one i found i just sprayed on a towell and wiped it of . DO NOT SPRAY WITH CAR RUNNING!! that stuff is very flamable.

 

I cleaned the throttle body with CRC Throttle body cleaner. The label said it was coating safe but in fine print it said do not use on turbochargers, superchargers, etc but every product said that too!? I hope its safe, I didn't use a lot and I wiped most of it off.

I noticed that there wasn't a lot of space to work with so I had to take the airbox out incld. and the associated piping out to get to the pipe leading to the throttle body. Pictures below.


The outside looks ok.


There was a dark spot on the other side of the valve but it wasn't too bad.


Does this look like enough dirt on the towel (white blob)?

I reset the ECU and drove off. Everything seemed good so far idle is pretty smooth. I need to go on a longer drive to confirm.

 

if the idling problem was due to a dirty throttle body why wasn't it happening when the car was NA?

 

^-- Maybe whoever installed the piping didn't plug them back in all the way and air leaked and the process of cleaning the TB seated the pipes properly? Just a wild guess.

Ok idling problem fixed. I drove around for a bit, airport run and back so the engine is definately warmed. I still get the supercharger buzz but it idles smooth at red lights 650-700rpm.

 

yeah thats about my idle but occasionally it drops to 500 but never dies.

 

I just got my supercharger reflashed today and when you first start it even warm it has stalled on me twice parked.After I get going down the road its fine if I stop at a light it idles around 400-500.I had to drive it to dealer without reflash and it idled better before.I'm going to assume for now it needs a few days to learn.

 

It shouldn't take a few days to learn. Force a ECU reset by pulling the negative terminal on the batt for a few minutes (5+ minutes). Start the engine and let it idle (don't go anywhere) for 10 minutes and it should learn the proper AFR. My car never stalled after the S/C install it just idled rough. Throttlebody cleaning + ECU reset fixed that.