Last week i was replacing one of the upper intercooler piping, all oem othere then my air intake, which I took off to clean the inside of the pipe. Put everything back together, started the car. Started right up but 10sec later rpm's went up to about 2,200, stayed there for a few seconds. Then started to act up where it would rise up and come back down repeating. I didn't know what it could be, for some reason I decided to unplug the MAF, that moment it stopped doing that, went back down to normal idle. But was running really rich. Maybe bad maf?

 

It could be a bad MAF.

1. When you installed the UICP, did you do a complete boost leak test?

 

Don't think its a vacuum leak but I think ill try and swap out the maf with someone I know.

 

Why do you not think it's a boost leak? You just swapped a UICP. If the car was working fine before, and that's the only thing you changed, then that's where the diagnosis starts.

Get a spray bottle, and an air compressor, and check for leaks.

The MAFs job is to detect the correct amount of air, and tell the ECU how to handle it. Your car runs fine, but you just completely changed the amount of airflow the ECU and MAF are used to seeing. Did you disconnect your battery at all, because that will let the ECU re-learn. Otherwise, if you re-connected the MAF while the battery was still connected, you could've easily arc'd it.

1. Do a boost leak test and report back.

 

The battey was connect, did it mess the maf u think? And ill look into the boost leak this weekend.

 

Well... anytime you're connecting a hot circuit to a computer, you're asking for trouble. But you were having the problem BEFORE you pulled the MAF. So it's possible you could've fried it, but if nothing else has changed then start with a BLT.

The last couple cars I put IC pipes onto idled pretty wonky for a couple of minutes before it got back to normal, and after a couple miles of driving in and out of boost, it was no issue at all.

So I would probably:

1. Do a boost leak test (which is part of installing any component related to the turbo).
2. Disconnect the battery for a few minutes (or while you're doing the BLT).
3. Re-connect it, fire the car up, let it idle for a couple of minutes. After it seems to stabilize, go for an EASY drive.
4. The get it into and out of boost a bit to let the ECU work out the maps. (Don't go full boost right away in case the car leaned out)

Boom. Done.

 

Before I took the maf off the car, the car was running fine, problem stared when I put everything back together. I might have damaged the maf some how. I'll look into the BLT.

 

Looks like it was the maf, changed it with a used one and started up good and ran normal.