Engine holding back at wide open throttle

[The Arch Bishop]

It's fixed..... 

Anybody want to know what it was ?

Yes, I'm a tease....

[shnazzle]

Air leak

[The Arch Bishop]

Nope!

It was indeed that I'd replaced a dead MAF with another dead MAF. New Denso one in there and it runs beautifully. Fuel trims have dropped to normal values, the stuttering has stopped entirely and the power has all come back.

I believe I've learned a very very important lesson here.

More than three months wasted by using second hand parts. Although to be fair, the part I used was working when it came off the old car (I trust the person I got it from). Just bad luck and terrible timing.

[The Arch Bishop]

I'd also like to say a huge thanks to everyone who's helped me trying to sort this out with advice, lessons on how to read engine telemetry and spare parts to try out.

I feel a bit guilty for sort of wasting your time, but if it's any consolation, you've taught me a huge amount and been amazingly generous and I can't thank you enough!

(We need a group hug emoji one this forum)

[shnazzle]

Not a waste at all and I'm glad it's sorted.

I think, given the amount of knowledge on here now, it's time we step it up a notch.

If we had measured you maf signal, we may have known.

[The Arch Bishop]

Not a waste at all and I'm glad it's sorted.

I think, given the amount of knowledge on here now, it's time we step it up a notch.

If we had measured you maf signal, we may have known.

To be fair, looking at comparisons, the ranges don't look radically different between the old and new MAFs. Which is odd!