Engine Stutter around 3k revs

[8thumpers]

I have an issue around 3k revs. It feels like a misfire - but not as obvious - more sort of  bumpy acceleration thru 2.5 to 3.5k revs. When it hits 4k the vvti kicks in no problem.
It has had recent new sparkplugs which did cure a bad misfire.

Also suffering from a "rattle" at this same rev range - more top end than big end - could be piston slap??

Anyone cast any light? Cheers.

[2 of the left]

MMmmm Could be fuel supply at low revs

[jonbill]

I'd have a look at what the o2 sensors and fuel trims and ignition timing are doing in that rev range

[m1tch]

The rattle might be a heat shield although its usually at 2k rpm, as jonbill says, try and check the fuel trims, you could perhaps also reset the ECU by removing the ECU fuse in the engine bay for about 20 minutes as this will allow the engine to relearn things.

[shnazzle]

As we say... MAF MAF MAF  s:) s:)  
Pull that MAF off, give it a good spray inside with maf/carburettor cleaner, let it dry, reset ecu (remove negative battery cable for 20 mins or so), and see if that helps

Sent from my ONEPLUS A5000 using Tapatalk

[8thumpers]

MAF does sound most likely... it hasn't got any heat shields so that is rules out. I'll pull the MAF..

[ptennisnet]

Don't forget to remove the O ring before spraying with the carb cleaner.

[8thumpers]

Don't forget to remove the O ring before spraying with the carb cleaner.

Ok cheers [emoji106]