I’m looking for technical help or recommendations on: Fault finding
I bought my second MX5 just over a month ago but I’m afraid my heart ruled my head and I bought it even though it had an engine flat spot.
It’s intermittent (yay, everyone’s favourite type of problem to diagnose…) and only seems to be a problem below 3 - 3.5K revs. It ticks over fine, starts on the button and otherwise seems fine.
I took it to the local main dealer who told me they spent over an hour trying to find the fault. Their conclusion was it was a loose wire somewhere in the loom and that I should see what webuyanycar.com would give me for it. They charged me £180 for their wisdom and made a few comments about how old the car was to boot… It’s a 61 plate!
I’m just wondering what thoughts on next steps might be; I can sell it as they suggested and nearly break even but it’s a good car otherwise. Does anyone know of a decent automotive electrician localish to me? Maybe I’m just on a hiding to nowhere and I should just give up on the old girl?
Classic main dealer response really! What did they actually check/diagnose for the £180?
First disconnect the battery negative for half an hour, reconnect and take it on a decent test route. Allow the ECU to re-learn. If it’s the same then…
I’d consider spark plugs, whether the MAF might need a clean, also fuel being used - run two tanks of Momentum or V-Power through and see if that has any improvement.
I find my 2006 NC1 sport feels a touch dozy in 1st & 2nd.
Then I tried a remapped NC1 sport and that was much better.
I believe that Mazda have programmed in “dozy mode” in 1st & 2nd to give the traction control an easier life.
When the cars get remapped - the tuner usually removes “dozy mode”
yup! There is definitely a " torque restriction " built into the standard map. having them removed certainly made 1st & 2nd feel a tad more …errr…useful when I had my nc3 remapped.
I’ve never had much faith in main dealers after a few bad experiences and this is another black mark.
TBF they confirmed it wasn’t a earth fault and it’s a canbus problem which kind of makes sense, I does feel like when the traction control kicks in and when you lift off the power comes back for a fraction of a second.
I might do the plugs anyway as it’s just ticked over 60k miles.
I think my mk3 has had a remap as the throttle is a bit twitchy when you first touch the pedal, I don’t think it’s that though as it barely accelerates even on the flat.
I’m wondering if it’s related to the traction control somehow as I never see the light flash on the dash whereas my mk3 would kick in even when pulling out from a junction and I was taking it easy.
I get a little ‘kick’ just after 2.5k revs. Sort of the opposite of a flat spot sort of thingy. I wouldn’t mention it normally because people laugh at you, but this seems a good opportunity to slip it in like….
Are there any other saddos out there with a mini power band?
I cleaned the MAF yesterday but it’s not made any difference unfortunately, I’ll try ringing round a few automotive electricians today and see if they want to try and figure it out.
I’ve run a tank and a bit of V Power through it since I’ve got it and I’ve disconnected the battery. Looks like the main dealer did too as it forgot all the stereo settings.
I would take it somewhere like performance Link, it could be a bad re-map and therefore you will never find it until they put in on the rollers/plug into the ECU.
The main dealers commenting obout the age of the car tells you all you need to know.
If it was me I would go with CD’s suggestion. It’s the only way I’m thinking. It’s just you saying it’s intermittent I find odd.
It may be your swirl flaps in the intake sticking or not opening when needed. They are vacuum operated and are meant to provide more torque at lower rpm, then open to give more airflow for higher rpm. Sometimes they stick in places causing a restriction.
That’s a good point but it tends to happen in specific models of specific cars. I haven’t seen this in respect of theMX5. It happened in some models of theAudi TT for example. I’m aware of it as I have a TT.
Yeah definitely not a common issue on MX5 but it does happen. Pretty easy check to see if the actuator still moves smoothly and if the vacuum line is still attached.
I randomly checked the MOT history again this morning and last year there was an MOT failure for ABS and DSC warning lights which would make a lot of sense as the traction control doesn’t kick in until the wheels have totally lost traction. The car drive 3 miles and it passed the same day which doesn’t seem like a long time to fix all the issues.
No idea how I missed this when I did the car checks though! Maybe I did and my memory’s going…
I’ve booked it in with an automotive electrician in two weeks so hopefully they can pinpoint the problem.
