Help! Just finished installing my supercharger...now I have a rough idle during cooler mornings... once the engine warms up ... or I rev the engine a couple of times it smoothens out... what can the problem be?

 

Just a wild guess but try cleaning the maf?

I once had a similar prob with my non charged/turbo'ed, and it was just that the maf was abit messy.

 

I cleaned the maf when installed the supercharger.

 

A rough idle at cold start that smooths out when the engine gets warm (and revving the engine counts towards that) suggests the air temp or coolant temp sensor inputs to the engine controller are wrong, signaling the air or coolant temp is warmer than it actually is.

As a result the engine controller doesn't supply a rich enough mixture when the engine is cold and rough running, with possibly some intake spit back though this may be masked now with the supercharger present, is the result.

You can check the intake air temp and the coolant temp before cold engine start with an OBD2 code reader/data viewer and if either (or both) are too far removed from ambient, well you have a good lead.

You can try disconnecting the MAF from the engine wiring harness, clear the codes (even if none are present this also erases the adaptation the engine controller has learned with the MAF connected) and start the engine engine and run the engine some. Now the engine may not show any improvement right away, or it may run worse, because you have erased the learning. The engine controller will need time to relearn absent the MAF.

However, it just occurred to me that with the supercharger the engine controller may be hardpressed to adapt since its adaptability is based on the engine being naturally aspirated.

Well, up to you if you want to try the the MAF disconnect or not.

Since the engine just had a supercharger fitted you need to go back over all vacuum lines, fittings, and fuel lines and such to make sure all are good, no cracks, or loose connections.

Generally when something like a supercharger is fitted it is a pretty good idea to renew all vacuum lines because the original ones are old and close to perhaps cracking. The handling they get subjected to when the supercharger is being installed can send them over the edge.

Which prompts me to ask: Since you were at the engine installing a supercharger is the secondary air injection system still installed and working properly?

Sincerely,

Macster.