Started to get some hesitation from about 5000rpm onwards, but only on full throttle. If you ease off the gas pedal slightly it will continue accelerating smoothly.

 

Also seem to get fuel smell on start up coming through air vents.

 

Coincidence ? or separate problems ?

 

Goin' to remove centre plastic cover in the morning and check for fuel leaks. Have tightened everything else around fuel filter and although needed tightening no change.

 

Also goin' to change spark plugs tomorrow ?

 

Just had a thought- I am just coming to the end of a full tank of Optimax that my UK zed hasn't had before. Perhaps?

 

Any thoughts appreciated !!!!!:confused:

Could either be the fuel pressure regulator, fuel damper or holes in the hoses. The fuel smell when cold is a dead give away. Once the engine gets warm the rubber expands and the holes will close up stopping the smell.

 

Have a look under the engine section of my web site to check you have tightened all the hoses. You can also use a little talcum powder to check the fule for leaks.

 

When was the last time you changed the fuel filter ?.

Presumed it was done on last service, as I have only had it a couple of months.

 

However I am learning fast when it comes to Zeds- Never presume anything!!!!

 

Will get these jobs done today and inspect fuel filter.

 

Cheers for advice.

I had this, and the problem dissapeared once I started using either Super or Optimax!

 

You say its your first tank of Optimax, and its only just started happening, is yours a J'Spec or UK? J'spec expect at least 98 RON and preferabally 100 RON (not achievable in the UK without Octane Booster).

 

I put my problem down to leaning out top end and as I said once I started using 98RON its been fine - my suggestion would be another tank of hi-spec go juice and see what happens.

 

Oh, btw my Sainsburys has just started selling Super - I'm clocking up the points and will soon be able to charter Concorde on my Air Miles :D

 

HTH

 

Tim

Cheers SMW1 for sound advice and top website!!

 

Under the Nissan cover at the front of the engine is a short piece of flexible fuel pipe with a clamp that was mighty loose. About 6 whole turns later no fuel leak.

 

Also replaced spark plugs-hesitation could also have been the fact that I had no more than about 40% of an electrode on every plug. Nice eh!!

Put in some NGK Iridium plugs.

 

BIG Noticable difference.

 

Think I will change fuel filter as a matter of course. Tightened every fuel connection under the Nissan plastic cover and several were pretty loose. Amazing how loose they get in the winter.

 

So hopefully no more fuel smell or hesitation :D

Excellent glad I could help. Funny you should mention it but it seems that I had my fuel leak from exactly the same clamp as you. My site is growing by the week. Everytime I do something new with the car it gets put in there :) .

 

Remeber to tone down the pressure in the fuel lines before changing the filter. This link is pretty good although the web site can be a little slow at times.

http://www.marsavius.net/zippin/ztech/fuelfilter/ff.html

Andrew,

 

Did you get the hesitation problem fixed. The reason I ask is that I am getting exactly the same thing on my J spec Z. I generally alternate between super unleaded and optimax when I can get it. I never use normal unleaded.

 

Did changing the spark plugs sort it.

 

Any help would be appreciated.

 

Cheers,

 

 

 

Dean

No hesitation at all anymore. The spark plugs were well knackered !!Looked like they had been in there for the full 72,000 miles of my engines life.

 

Seems to be fine now, although can't really give it a full testing in this shitty weather.