This is a repost on a new account, on a diffrent thread(i previously posted on the wrong thread, im new to the forum)

Hey guys, i'm new to the evo scene and have recently purchased my first Evo 4 GSR, i have never worked on a boosted vehicle. The car was clearly a project build as i expected and by no means am i a mechanic but i've worked on cars here and there. I've been told the original owner of the car put aftermarket cams on as well as a valve controller, i was told he swapped the engine with an evo 5's. I have a strong feeling as the car runs very rich it was never tuned properly, the car was having issues dying at low rpms and it runs okay once it gets moving. Today (being in canada as well) the car doesnt want to start in the cold now. Where should i start? The spark plugs were recently changed. It also has an issue with going WoT, but i was told the car needs a new MAF sensor so i think that could be the issue but i'll leave that for another day.

 

The "valve controller" is just a boost controller and doesn't do anything at idle. Since you have cams, you need tuning or it's going to run worse than stock - there is no good way around this. If they are bigger cams, you'll run much reduced vacuum at idle and the ECU will be very confused, hence the poor low-speed performance. Since you need the whole thing tuned anyway, pitch the silly (and possibly broken) MAF and convert it to Speed Density. Do a boost leak test after that, and see where you're at. There is no sense in trying to get it running without messing with the ECU, and you probably can't diagnose a bad MAF on a car that can barely run in the first place.

 

Thanks a ton for the reply!

​​​​Tuning is definately on the top of the list, just trying to get everything in good working order before i actually transport it roughly 4 hours away to get the tuning done.(is there an etune possible for this situation to make my life easier?) I havent even heard of the speed density conversion yet but i'll be looking into it!

Thanks again!