Mysterious big loss of power/drive on Spa circuit during parade laps.🤔

Does anyone have any suggestions please.

Last Saturday during the parade laps on an open straight I floored the throttle in 3rd, 4th or 5th gear.

When the revs reached about 6500-7000, the whole car suddenly jumped and the revs rushed up but all power was gone.
My first thought was that I blew the engine and I immediately slowed down. To my surprise, I noticed the car was still pulling well when I gave some throttle. There was no smoke, no suspicious sounds and no lights on the dashboard - everything seemed normal?

I continued driving and everything seemed just fine under normal acceleration and loads but as soon as I gave it maximum power over 6000 rpm the same thing happened again and again.

After 3 or 4 times of this happening I decided not to go flat out above 6000rpms. Now I want to know what might have happened, because it was a first time experience in 21years of ownership, much spirited driving, lots of track days and a far few wild parade laps at many circuits and now I don't trust the car like before.

Has anyone ever experienced this fault and if so what cured it for you???

I will be sprinting it up the Beaulieu house drive tomorrow morning and afternoon when the chequered flag drops, it may well do it again under these conditions so I will report back as to what happened.

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Originally Posted by Pride

lots of track days

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It could point to a weak fuel pump but it doesn't have to be. On track cars the fuel pump wears out sooner. How many miles now? Be careful while testing this.

I'd mount a fuel pressure gauge on top of the fuel filter and would monitor the fuel pressure with a small camera in the engine bay. If the fuel pressure drops you have a hint. At least the behaviour seems to be consistent (WOT above 6k rpm), so the chances are good that you'll soon find out.

144,000 miles, new fuel filter about 2,000 miles ago.

What gauge should I buy, any links or suggestions from Amazon ???

If it has never been changed it's surely a candidate.

I've used a similar to this one: https://www.ebay.com/itm/Fuel-Pressu...LH_TitleDesc=0

I'd already suggested the fuel pump but is it possible for the cambelt to jump a tooth? Not so sure given the long V configuration but a wrongly timed engine can give similar situations...

it seems like the fuel pump is getting blamed for everything just lately lol!!!!

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revs reached about 6500-7000, the whole car suddenly jumped and the revs rushed up but all power was gone.

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i think 'the revs rushed up' may be the critical statement here.... losing power but the revs rushing up sounds like the drive unloading..... so i'd be looking in the clutch direction...

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Originally Posted by britlude

it seems like the fuel pump is getting blamed for everything just lately lol!!!!



i think 'the revs rushed up' may be the critical statement here.... losing power but the revs rushing up sounds like the drive unloading..... so i'd be looking in the clutch direction...

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I thought the same... Clive had a new clutch fitted last year (?), maybe clutch pedal needs adjusting? Check the pedal clearance....

Also assuming there are no error codes stored?

If the TB should be off you'd see it in a simple emission test with HC all over the place.

I didn't read anywhere that the clutch pedal needs to be adjusted with a new clutch. But good hint. If the revs really rushed up it could point to the clutch.

The key question is in which manner the revs rushed up:
1. If the engine was reving more quickly at the moment you 'fell' a loss of acceleration (I do intentionally not use the word 'power') it could be related to the drivetrain/clutch indeed.
2. If the revs still were still climbing but at a lower rate you had less power from the engine.

What speaks against no. 1:

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Originally Posted by Pride

the whole car suddenly jumped and the revs rushed up but all power was gone.

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A clutch would never do this. The transistions are much more uniform if the clutch is slipping.
This could only be induced by a sudden lack of power delivery of the engine. This could also induce a cluch slipping but only for a fraction of a second.

Let's see what additional info Clive can give to us.

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Originally Posted by NSXGB

I thought the same... Clive had a new clutch fitted last year (?), maybe clutch pedal needs adjusting? Check the pedal clearance....

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He said it was "initialised" properly when fitted...