Since I've had my car its had an annoying hesitation between 2750 and 3250.

When increasing speed it stutters/hesitates through this range then clears up afterwards. When driving at bang on 3K its quite noticeable and you can feel it stuttering. When you increase load at 3K it stutters for a second then away it will go - although on a run last night it didn't really feel like it was boosting very smoothly. It does it whether cruising at 3K or when speeding up through the range mentioned above.

So far I've disconnected the Lambda Sensor (The sensor at the top of the down pipe, yes?) Which didn't make any difference.

This morning I disconnected the MAF sensor and the car continued to run although irratically. I thought when you disconnect the MAF it should eventually cut out? The engine was cold though - would that make a difference?

Car is an MY00 Type RA VF29 with ECUTEK mapping and it does have a K&N induction kit. Possibility of headers flowed but waiting on previous owner to confirm.

I've got a PSi3 data monitor and it comes up with no fault codes.

Any ideas chaps? Its really bugging me now.

 

Could be the MAF on the way out. I know when i disconnect mine it stalls, your ECU may have 'learnt' the MAF has deteriated and compensated for it, IIRC the MAF on yours is of the 'delicate' type and the use of a IK is not reccommended as the vibration causes it to fail even quicker

Saying that, as you have ECUTEK it may be worth getting it checked by the mapper. Hth

 

Anyone?

I've bought a new MAF so will fit that when it comes. I'm not convinced it is the cause though.

 

What does the engine coolant read? I had a fault exactly like yours. My Apexi Commander was reading the engine temp up and down between -34 to 88 within seconds. I changed that and problem solved.

The only thing thats makes me think it might not be that is your problems goes after 3k revs, that makes me think its a fuelling issue, or ignition problem.

If the cars due a service I'd say change the plugs and leads, if no joy check the coil packs they can fail and cause similar problems.

 

Coolant on the monitor seems pretty steady. Low 80s to mid 90s.

The plugs, leads and pack are next. I went for the MAF anyway becuase with the induction kit its probably worth replacing it/having a spare.

Cheers

 

If the coolant temp is stable it won't be that then.

I recon the coil packs or a fuelling problem, something like faulty fuel regulator.

 

Can you see the voltage reading of the maf on the data monitor?