Won't rev no power above 4500rpm

[Mickygee]

Posted recently about electrical probs (fuel pump relay) and detached advance and retard.

These issues have now been resolved (new relay, vac advance reattached).

However the lack of power issue for which I started looking at the electrics in the first place is still there.....

The car idles fine has plenty of torque and low to mid range grunt, but when you give it a bit of welly say in second once you get to about 4500 rpm revs rise very slowly and even at full throttle it won't rev past 5500rpm.

Until recently it was quite the opposite once you got past 3500 rpm it would very quickly flick round to 6000rpm.

The engine is a NCK 4441cc BV rebuilt by V8 Developments with only 10,000 mile on it. No mechanical noises from engine.


I am guessing the issue is fuelling or airflow, can't see it being a timing issue? And I hope it isn't knackered cam(V8 Developments 218 hybrid)as the mileage is so low and oil changes have been very regular.

Were do I start to try and pin this one down, I guess checking the fuel rail pressure is as good as place as any ?

Any advice would be apperciated.

[GreenV8S]

Have a careful look at the induction between the filter and throttle. It's been known for the induction hoses to delaminate and collapse inwards under full load, causing a huge power loss.

[Mickygee]

Thanks for the advice, the induction hose just prior to the airflow meter had delaminated and collapsed (see pics). Where is the best place to get a replacement and are there any better materials available now ?

Cheers !

[BicesterGriff]

Speak to tim at ACT

[davep]

Mickygee said:

Thanks for the advice, the induction hose just prior to the airflow meter had delaminated and collapsed (see pics). Where is the best place to get a replacement and are there any better materials available now ?

Cheers !

Try ACT Induction hose:

http://www.actproducts.co.uk/shop/induction-hose-k...

[Mickygee]

Ta !

[griffdude]

Also a good idea to cover the smooth hose with sticky backed aluminum tape, as you'll appreciate it gets quite hot above the exhaust manifold.

[Uncle Fester]

ACT also offer a tube made of heat shield material that slides over their inlet pipe.