NB8B cold start stutter

aviper4u · Postby **aviper4u** » Sat Mar 05, 2011 1:02 pm

When starting in the morning, car starts then attempts to stall though recovers and then runs fine afterwards even when restarting after drive

Only recent changes were tightening alt/water pump belt as would screech with lights and windows functioning.

cheers

93_Clubman · Postby **93_Clubman** » Tue Mar 08, 2011 2:59 pm

On the NA this was usually a faulty temp sensor for the ECU - see pic at figure 5 half way down this page: http://www.miata.net/garage/CoolingSystemProblems.html

But it could also be a plug lead, although symptoms are usually different:
viewtopic.php?f=29&t=23528

More suggestions:
viewtopic.php?f=29&t=42171
viewtopic.php?f=29&t=40375

aviper4u · Postby **aviper4u** » Tue Mar 08, 2011 8:22 pm

some good leads there though no exact scenario or maybe my car just needs some more time..........

fair bit about spark leads and coils though how can that be the case when stutter only happens on first start of the day and no stall.

anyways will keep updating with anything new

Charlie Brown · Postby **Charlie Brown** » Wed Mar 09, 2011 9:23 am

aviper4u wrote:how can that be the case when stutter only happens on first start of the day and no stall.

The motor and running gear is cold first up. Second and subsequent starts the motor is warm so if you have a bad wiring (spark or other) connection, it may close up as the cable expands.

If the car has the original spark plug leads I’d go with replacing them first up, after all they could be 10 years old.

Next I’d pull the plugs before the first cold start and have a look at them. See if there’s any oil on them. If so then your rings or valve stem seals are on the way out.

aviper4u · Postby **aviper4u** » Wed Mar 09, 2011 2:57 pm

the spark leads of the nb8b are the type that are different from earlier models, anyone out there changed these coil/spark leads on their nb8b to resolve any issues?

Locutus · Postby **Locutus** » Wed Mar 09, 2011 3:04 pm

you can borrow my coils if you promise to give them back.

aviper4u · Postby **aviper4u** » Wed Mar 09, 2011 4:22 pm

ah yea

ill give em back.........

Garry · Postby **Garry** » Wed Mar 09, 2011 7:14 pm

Mine does the same thing. It's worse after sitting around for a few weeks, then sometimes it's bad enough to stall, but it refires straight away and then runs fine. If I drive it every day it doesn't do it. I thought it might be a fuel priming issue but I haven't spent any time investigating seeing as everything works fine after the initial cold start. Let me know if you find the cause.

aviper4u · Postby **aviper4u** » Thu Mar 10, 2011 9:23 am

hmm interesting as i have had the car for a year and only did something like this when battery was bad about a year ago but that required throttle depression to save.........

car has not had the prob since new batery and only ever started it on the weekends though now as you say saves itself and then runs fine...

anyways will prolly just live with it unless it gets worse

bear2230 · Postby **bear2230** » Thu Mar 10, 2011 11:18 am

Mine does the same thing too. usually after not being dríven for a couple of days. It only happens occasionally and I put it down as just being a quirk. I would also like to know what is was if you ever found out.