mx5cartalk.com

I have random power loss in my 2001 NB with k&n typhoon, new magnacore leads and new battery. It can happen any time if the engine is hot or cold, with a full or near empty fuel tank. I drive 400km a week and it can not happen for months at a time and then out of the blue it happens. It is happening more frequently now and almost every day or so since my 120000km service a couple of weeks ago (new plugs). This is what happened yesterday:

After 20 minutes of spirited driving I was on a long straight flat road in 4th gear at a steady 4000rpm when it happened. Low droning from the intake and no acceleration if I floor the throttle. But steady speed; no slowing down. I dropped it into third and the revs jumped up from a steady 4 to a steady 5. (no wobble from the needle). Again, no acceleration flooring the throttle and no slow down. No smell of fuel. After about 15 seconds I caught a whiff of too hot rubber so slowed down to pull over. As soon as I did it came back and I was off.

Then it struck me that it behaves exactly the same as if I have hit a steep hill and I'm in too high a gear. The intake starts barking low and slow and I don't get any acceleration if I floor the throttle.

To confuse matters: The last time I went to Wakefield it was doing this consistently. Every session after about 5 laps it would strike around turn 9. Which suggests it's heat related but then it can happen first thing in the morning after a just a few minutes.

I have tried a new cam sensor. No joy.

It did not fail when it was up on the dyno in an attempt to reproduce.

Any ideas ?

Thanks.

maybe a fuel pump or fuel filter problem?

borrow somone's cam angle sensor, take it for a very spirited drive.

I assume you have an nb8b with the vvt....

I agree it may be your fuel pump breaking down and not supplying enough flow or pressure.
I had a similar problem with a different type of car that is on gas. When I switched to petrol I could cruise but could not accelerate.
The problem with that car turned out to a faulty injector.
Maybe that is something to look at too.
Cheers

Or coilpacks...

Thanks for the advice so far...
This morning the problem manifested as hesitation for a couple of seconds when getting back on the throttle after gentle braking.
wun991: I have a new cam sensor and yes it's an nb8b with vvt
fuel pump, injectors, coilpacks... This list is looking good. Any other likely suspects?
The question then is what order to start swapping out these parts.

Pull the leads out ....clean and reseat them...

It could be as simple as a dodgy connection?

Where are you?

If you are in Sydney I can lend you some coilpacks and cam angle sensor to try out. They're not the best (have done 230000km) but they still work...

Caffeine's old coilpacks worked a treat so I have installed new and am 99% sure I am all fixed.
I have a run at Wakefield next month which should confirm.
Many thanks to this community and Caffeine.

Nice one Liam, keep us posted on how it goes. Fingers crossed you've found the issue.