On my way back from work tonight in 4th and 5th I noticed the car felt like it was surging, almost like it couldn't make up its mind wether to accelerate or not. First few gears are fine, if anything in the cold going better than ever As my tank was low (but not on fumes low) I stopped and topped up the liquid tax thinking maybe it wasn't getting the juice it needed, but it was still doing it after filling up.

Car is an 02wrx with vf30 and associated bits (injectors intercooler ect) and has never done this before at all. Now I may be wrong but I think it may be compressor surge, I understand some vf turbos can be prone to it but why has it only come about this morning when temps were down too -5??

As I changed turbo and mapped in the summer I haven't really driven too much in the cold with it, I'm just hoping its nothing too ugly too worry about

 

May just be the cold air, cold = more dense therefore leaner running.

 

I will have too take it for a blast for 'testing purposes' when it warms up a few degrees

 

I shortly need my map tweaking, I will ask the mapper see what he says. Was thinking of adding a 3 port at the same time, maybe this will help a bit.

 

mine was doing that was a dirty maf sensor cleaned it and was fine.

 

mines doing the same it's the cold weather i would say, i had my map backed off a bit in 4th and 5th which helped but it still does it a bit so i'm just taking it a bit easier till weather warms up

 

Went for a mess around in the snow today, temp was up to 2 degrees and no apparent sign of surging so hope it was the low temp that was the problem. May try cleaning the MAF sensor as well just to cover all the bases.