i have a single setup. I was cruising and did a 3rd gear pull and the car backfired so i pushed in teh clutch and the idle was goin nuts. It would go between 2-4rpm on its own and i lost my brakes. The brakes felt really mushy. I was limping the car back home when the car fixed itself. The idle is still acting wierd, bouncing around at 2200rpm and if i rev it it comes down really slowly. I check a lot of vaccum hoses and cant find any cracks or popped off hoses. It has a brand new map sensor on the car. I have driven the car about another 100miles and it drives perfectly fine with exception to the wierd idle. any suggestions?

 

ok kinda a stretch but something to check

brake booster check valve/ diaphram /hose.

if one of those failed it could allow a significant amount of unmetered air into the engine causing the bouncy idle and the loss of the booster would cause a less sensitive brake pedal which if there was already some air in the system would make it seem to be more squishy than normal because you would have to push harder than normal to get it to stop.

 

check TPS