Maintaining a used MX5 NB3B (2003)

smy0003 · Postby **smy0003** » Tue Sep 08, 2015 4:25 pm

Yep. My nb8b did that.
Something the 1300 or 1400 revs in first in the carpark, all feet off the pedals it would hop.
I just dipped the clutch a bit earlier.
My NA8 doesn't do it though. Different fuelling or flywheel weights maybe?
Who knows.
Never had a problem with it and just drove around it.

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slipshot · Postby **slipshot** » Tue Sep 08, 2015 4:48 pm

smy0003 wrote:Yep. My nb8b did that.
Something the 1300 or 1400 revs in first in the carpark, all feet off the pedals it would hop.
I just dipped the clutch a bit earlier.
My NA8 doesn't do it though. Different fuelling or flywheel weights maybe?
Who knows.
Never had a problem with it and just drove around it.

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Thanks chap - good to know. As opposed to the juddering clutch which afflicted many (including mine), I wonder if this is age related or some other minor thing. Will keep people appraised when I collect the car later.

joshuam · Postby **joshuam** » Tue Sep 08, 2015 5:07 pm

slipshot wrote:
smy0003 wrote:Yep. My nb8b did that.
Something the 1300 or 1400 revs in first in the carpark, all feet off the pedals it would hop.
I just dipped the clutch a bit earlier.
My NA8 doesn't do it though. Different fuelling or flywheel weights maybe?
Who knows.
Never had a problem with it and just drove around it.

Sent from my GT-I9505 using Tapatalk

Thanks chap - good to know. As opposed to the juddering clutch which afflicted many (including mine), I wonder if this is age related or some other minor thing. Will keep people appraised when I collect the car later.

Yeah, my NB8B has a very rough factory clutch. It unfortunately has heaps of life left in it, but it very hard to drive at low speed coming on and off the clutch all the time because it hops and carries on unless you slip the clutch which I can't stand either

I don't have your problem at 1500+rpm though.

smy0003 · Postby **smy0003** » Tue Sep 08, 2015 5:18 pm

Yep my clutch was fine. This happened when slowing down in 1st feet off all the pedals.
Keen to know what the cause is.

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speed · Postby **speed** » Tue Sep 08, 2015 6:20 pm

Does the nb have an EGR valve?
If so I'd be cleaning that.
Have had cars that do what your describing on very light or no throttle. Don't have a nb so can't comment further

de Bounce · Postby **de Bounce** » Tue Sep 08, 2015 6:47 pm

The idle issue can be one of a couple of things.
To identify if it's the IAC, set the base idle by disconnecting the IAC and adjusting the throttle stop until it idles at 850 rpm.
Go for a drive with the IAC disconnected, if that stops the idle issue then IAC is the problem.

You can try and clean it, good luck with that!
More info is available including a guide on how to clean the IAC on the big forum

slipshot · Postby **slipshot** » Wed Sep 09, 2015 9:42 am

So, the wee beast came back last night. It needed new brake pads on the front ($99) and a lower coolant hose ($68) plus we replaced the thermostat ($48) to be sure as it makes sense. The best bit was looking through the stuff that had been removed. It was obvious (and the car clicked over the 150,000km mark driving home) that this was the original timing belt so the precautionary measure as definitely the right one. It was pretty worn and perishing all over too. You could also see on the tensioner pulley where it was on its' very last setting so was actually becoming quite loose as well. Likewise when spinning the two pulleys and the water pump, you could hear the noisy bearings and could tell that one would have failed sooner or later. So very glad it's all done. New fuel filter (old one not too bad), new spark plugs (old ones were pretty good too), and the diff oil and gearbox oil.... gearbox oil was not too bad and needed changing. Diff oil was horrible - changed not a moment too soon. Plus a few new drive belts (both alternator and power steering ones were very worn) and the car feels fresher. Certainly it seems to be running sweeter and the idling is dead steady at 850 rpm.

But the bunny hopping still exists when it is warm. So potentially the EGR valve or potentially the throttle body and associated items. Will have to see how we go...

Next thing is a proper clean with steam cleaning the seats and carpet, having my local magician fix the small marks/holes in the side of the seat and door skin, and for me to replace the hood handles, rubber gearbox boots and a few other things before the new headunit speakers and amp go in...

slipshot · Postby **slipshot** » Wed Sep 09, 2015 10:05 am

A replacement key...

Blimey, what a kerfuffle. I used to think that a replacement key was relatively easy, especially on a 13 year old car but nope. The few places I went to all looked at it and said it should be fine, then put it in their machine and then told me 'this is a special crypto-key that you need special technology to be able to do it'. After some tracking down I spoke to a chap at JB and Co Locksmiths in East Bentleigh, Vic, who said there's not been an MX5 key yet he could do but I would need the car there at the time. I head down there, he looks and says 'ah, we can do virtually all of them but for some reason this one is unique and although I've not seen one before, he knew of others that had. He then said I should head to Oakleigh Locksmiths (Atherton Road) which is where he sends all strange requests.

And they were great - apparently some MX-5's such as my 2003 model have crypto keys that require a bit more work. It took him about 15 minutes to cut and program the key but he did it and it cost $155, which given the cheapest quote I had was $125 (and they could not do it) and the most expensive was $360, I was happy. It all works fine too. So anyone who has issue obtaining a replacement key, these boys were successful.

I also looked into a new or second hand remote for the central locking - that is most definitely not required as unless I found a decent price used remote (about $150 upwards) a new one is in the region of $400+. Crazy...

slipshot · Postby **slipshot** » Wed Sep 30, 2015 7:32 pm

And the next challenge - repairing the damage to the door and seat which were rather harsh and not something I could have done so, I use a guy called David Prince that has been a magician in the past with vehicles that have incurred damage and once again he came up trumps. Very impressed. So the areas - the drivers side thigh bolster, the door card which was a nice little chunk and tear and the trim by the seat belt that someone had obviously tried to fix and it not really worked. And he also cleaned up my steering wheel too... Anyhow, here's the before and after for a total of $120.

SileNceR · Postby **SileNceR** » Thu Oct 01, 2015 2:34 pm

slipshot wrote:I also looked into a new or second hand remote for the central locking - that is most definitely not required as unless I found a decent price used remote (about $150 upwards) a new one is in the region of $400+. Crazy...

I paid $60 for my second hand fob.

slipshot · Postby **slipshot** » Mon Oct 19, 2015 11:48 am

Latest jobs done

Installation of Garage Star Delrin door bushes

Easy to install and do they make a difference - yes they do. Car is tighter and taughter, with less rattles and scuttle shake over bumps in the road and just feels a little bit more planted. A worthwhile upgrade and recommended.

Foamectomy

Took about 1" or so out of the bottom of the drivers seat - still comfy and makes a difference in that I am slightly lower - I'm 6' 1" and I still have a steering wheel that is a bit too large and so the legs look a bit bandy but I can live with that. May try and remove some of the rear lumbar support to sit a little further back too but that is for another time.

Head unit replacement

Being finished off today but the standard (weak) head unit and speaker have now all been replaced with an Alpine head unit, Boston Accoustic 6" speakers and crossovers with tweeters, all fed by a 250W Alpine amp that has been very well hidden away in the boot on the vertical left side of the boot area. Sounds wicked and so much better than usual, with Bluetooth and all that other funky stuff. Pics if required.

MAF Sensor & EGR Valve

Took both of these off at the weekend and gave them a good clean. EGR valve was dirty as expected and was fine. Used throttle body cleaner and let it soak for a while. The MAF sensor looked fine and clean but of course you could not see it. Using MAF sensor cleaner I gave it a good spray from both directions and then soaked a cotton bud/Q tip in the fluid and very gently wiped all along the metal probe to ensure it was as clean as could be. Let it dry and reinstalled. And this made a difference - the engine was smoother and sweeter and just ran that little bit better so I'm glad I did that. Now I also know that this could just be a placebo... and that like a clean car runs so much better than a dirty car, this could be the same, but it certainly felt better anyway.

davekmoore · Postby **davekmoore** » Mon Oct 19, 2015 3:45 pm

Don't swap the indicator and wipers stalks. What you have now is correct for UK and all other right hand drive markets.

slipshot · Postby **slipshot** » Mon Oct 19, 2015 4:13 pm

davekmoore wrote:Don't swap the indicator and wipers stalks. What you have now is correct for UK and all other right hand drive markets.

Whoops - too late! Not that it matters, dead easy to change back now I know and really it's about what suits me as the driver rather than anything else. Bit like choosing the colour of a car - all personal preference and I much prefer it this way, and while it may not be 'right', it is what virtually every car in the UK has and what I'm used to and prefer.

slipshot · Postby **slipshot** » Wed Nov 11, 2015 6:04 pm

Ok, next round of stuff done.

The head unit, speakers and amp install all went well. One thing I found out was that the wiring loom I bought to support the head unit install did NOT lower the (electric) aerial when any other source was chosen so the aerial was always up. That's now fixed with a neat button hidden away in the elbow under arm console, which is also where the USB extension cable now sits for charging phones etc. The head unit is an Alpine CDE-178BT for streaming and calls, coupled with Boston Acoustics 6" speakers/splits and crossovers in the doors and a 250w Alpine amp nicely nestled in the boot. Quality sound and the limiting factor is the doors themselves but that's nothing new and I can live with it.

Images are after the car had a full detail, clay bar, polish and wax as well as the dealer-loved Armor All from the entire inside removed and leather conditioner on the dash to restore some originality... Also purchased, from a UK eBay seller, the new leather gear lever gaiter and handbrake cover in black leather with red stitching. Look great and make a world of difference from the original.

smy0003 · Postby **smy0003** » Wed Nov 11, 2015 7:09 pm

Your pics are upside down.
I've heard of others having issues with the aerial, I think it's the fault of the head unit itself. Both my JVC units did it just fine, and I bought the cheapest wiring harnesses I could possibly get.

Car is looking tidy!

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