I've got a flat spot roughly between 4000 - 5000 RPM that I'd like to get to the bottom of. It's fine up to 4K, a bit hesitant between 4K and 5K and then it picks back up again at 5K.
It used to have a random boost and hesitation problem below 4K but I seem to have solved that by having the following done. (the above flat spot was still an issue before doing any of the stuff below so these haven't caused it.)
- Change both Boost Solenoids.
- Change the standard AFM for another standard one.
- Change the turbo for a VXR one (as the seals were on their way out)
Aside from the above I'm still running standard map and all other stuff is standard too.
I'm thinking MAP or Lambda sensors may have been damaged by my old leaky turbo (although ECU lights not on)? Any other ideas?