Misfire in NB8B

Divo · Postby **Divo** » Wed Mar 27, 2013 9:39 pm

Have an intermittent miss in my clubman with an NB8B engine. Very annoying. Only starts missing once warmed up.
I have replaced the cam angle sensor, plugs and leads and coilpacks. (All new parts.) Using the Mazda fuel pump and standard ECU. Took it to MX5 Plus at Zillmere, but never played up for them while they had it.

Anyone suggest another honest reliable mechanic who knows MX5's in Brisbane, or can suggest what could be amiss?

I'm thinking maybe an injector issue, faulty fuel pump or crank angle sensor?

Cheers

Mark

project.r.racing · Postby **project.r.racing** » Wed Mar 27, 2013 9:58 pm

normally coilpack if it is a 'once warmed up issue.'

Gladiator · Postby **Gladiator** » Wed Mar 27, 2013 10:39 pm

You won't find better than MX5 Plus in Brissy.

Crapweasel · Postby **Crapweasel** » Wed Mar 27, 2013 10:50 pm

Divo wrote: Took it to MX5 Plus at Zillmere, but never played up for them while they had it.

Leave it there, problem solved.

Sorry, I had to.

Seriously though, yes another vote for MX5 Plus being the best there are in Brisbane.

PAU61L · Postby **PAU61L** » Wed Mar 27, 2013 11:11 pm

I had a similar problem, also I changed the crank angle sensor, but the problem went away when I swapped the air flow meter, hope this helps, Paul

Divo · Postby **Divo** » Fri Apr 05, 2013 5:58 pm

Fixed it !

Big thank you to Brisbane Tuning and Turbo, Nile St at the Gabba. Rob was great. He knows his stuff about MX5. I had a call an hour after I dropped it off to tell me the oxy sensor was dead and the fuel pressure regulator needed replacing.
They hook the car up to their gear while on the dyno and it checks out the codes if any.
I now also know all sensors, injectors etc... Are all functioning correctly too.

I'll be going back there instead of the "experts" at Zillmere in future.

A very satisfied customer

Cheers

Kev05 · Postby **Kev05** » Fri Apr 05, 2013 8:56 pm

Divo, good to hear you had the problem sorted. It's good to know that there is another place to go for second opinion.

Divo · Postby **Divo** » Fri Apr 12, 2013 8:39 pm

A further update

Fitted the new O2 sensor but ran worse again. Disconnect the sensor and runs perfectly. Took it back to Rob. He put it back on the Dyno and spent more time seeing if the issue could be found. All the mixture figures where within 0.03% of normal without the sensor fitted. He seemed to think that the position of the sensor in the exhaust could be affecting the poor performance of the sensor. We decided to run without it.

Upshot is no charge for extra time spent, and full refund on the new sensor!

Thanks again Rob! A good honest operator.