- My model of MX-5 is: __ mk 2.5 1.8 VVT
- I’m based near: __ Guildford
- I’m looking for technical help or recommendations on: __ engine warning light
My engine warning light has come on, took the car to a local mx5 specialist garage for some other works and asked them to check the engine light as well. I was told they couldn’t see a reason why so have cleared it and sent me on my way after a quick test run. The light literally came back on within 10 minutes on the way home. Is it possible for a warning light to come on without knowing what sensor triggered it?
Thanks for your attention, I’m happy applying logic to mechanicals but electrics and sensors are a closed book to me!
Which “MX5 Specialist”. Did they actually check for stored codes?
C&C Sparks in Bisley, Surrey. They seem to have brilliant reviews where ever you look.
Colin there told me that he just couldn’t see any error codes. I can’t understand why a check engine light could come on without there being an error message in place but I’m really don’t know that much about cars to be honest, I’m trying to learn though!
Michael,
Own an identical model to you and have had it 15 years.
Oddly, our light has come on ( over many years!) for a couple of days, stayed around for a few just to wind me up, then boogered off…for a year or two.
However, last time 2 years back it actually meant something. Turned out to be one of the COPS packs…which…wait for it…did not show a code. “Our Chap” tested them with some fandango thingamybob.
Fitted 2 new COPs Hunky Dory.
Check the leads & COPS maybe…
Wild guess ( as ours was judged) that the COP, or failing lead had an issue which only got known with a properly hot camcover… 
2 Likes
Hi Michael
I work with Colin Sparks, albeit remotely and would trust his judgement on this.
Checking for error codes is very easy and something you can do. Just plug in a cheap OBDII reader(MS309 @c £10) into the socket under the dash by the drivers right knee and turn the igntion on - it is that simple. All stored codes will be revealed. If there in an engine light on there will be a stored code. Are you sure it is an engine light and not another light, security for example?
1 Like
It’s definitely the engine light, no mistaking it. Every review and every person I come across that knows C&C Sparkes raves about them including on this forum so I trust their judgement I just don’t like getting ‘I’m not sure’ as an answer to anything. Better then a load of rubbish though I suppose!
I spoke to Colin about this last night again, he called me late bless him and has hypothesised that possibly disconnecting the battery has cleared the memory in the ECU. Seems the only possible explanation as neither of us can explain why the light would be on without an error code otherwise.
If I can will try and get Colin to have another look this week but I’m tempted to get an ODB 2 reader and have a look. The only thing I wonder is, even if I work out what it is, pretty unlikely I can fix it with my fear of electricals!
Give in to your temptation and spend a tenner on an OBDII reader, you know it makes sense:-)
Battery disconnection clears all stored errors but the light should go out too. If you have an engine light, there are errors. Did you disconnect the battery?
Just get the reader and interrogate the diagnostics next time the light comes on. My cheap MS309 actually tells you what the error codes mean, so no need to look up on google or ask on here. It would be interesting to hear back from you though.
1 Like
Agreed on the OBDII reader. Cheap and very easy to use. Even one which doesn’t provide the summary of the code is fine as we all have Google and a quick search will tell you what they mean and what you can do about them as well.
Further, if you have it connected to your phone while driving, you’ll find that there is a lot more information available to the ecu than is shown on the dash.
ODB2 reader ordered, for curiosity if nothing else. Just want to find out ASAP what the issue is really. I need a new alternator belt pulley anyway so needs to go back into the garage regardless. 
Part of wanting to buy an ODB2 is to see the rest of the additional info, especially if I start to mess around with the engine a bit more, I really think I want about 40bhp more to be honest…. My daily driver (Mini Cooper S) shouldn’t be quicker than my weekend car!
If it is the original Hitachi alternator I can supply you or Colin direct the pulley and retaining nut if required. Have a couple of the best ones left.
Just because a car has more power and is faster than your MX5, does not necessarily mean it is more fun to drive. A lot of people prefer the ownership/driving experience of an MX5 to much more prestigeous/powerful and faster cars. Not knocking the Mini though as enjoyed driving the one I played with a few years ago. What drove me to distraction with my 1600 Cooper(2001) was all the problems It had that I had to sort out.
1 Like
I’ve agreed with Colin I will drop in one day this week if I can sneak away from work and he will fit it while I wait. Impossible to complain about that kind of service!
I know what you mean and I’m not looking for a 911, going through corners and around roundabouts in the mx5 is a joy, getting a twitch of lift off oversteer from the Mini isn’t as satisfying as a roundabout well negotiated in the NB however, once past the roundabout I miss the torque of a 2.0 twin turbo in the Mini. If I could get that engine into the mx5 I would be a very happy man but failing that I really want another 40bhp in my mx5 eventually.
If that makes me a heathen in purist company then so be it!
Forced induction on the 5 is a very well trodden path, not least because the engine comes from a car which was originally turbo charged. As a result, there are lots of paths you can take.
The original ECU has no mapping options. It’s not very clever and is essentially fixed on the OEM mapping.
For another 40 horses, you could get an MP62 super charger with a piggy back module for the ECU. Very minimal installation and limited results.
You could build on that over time with extra complexity and get 60 or 70.
If you wanted to go further than that, a turbo can get you plenty but, if you push past about 230lb/ft, you’ll need to open the engine and install stronger rods.
By all means, go for it! The size of your budget is pretty much the only limit! 
You do what you like.
Could always borrow the CooperS supercharger, I think that is the Bofi solution.
I believe less stress than a turbo and probably get at least 40hp added minimum.
Quite an expensive package though from the look of it.
Please pass on my regards to Colin when you see him(Rob, MX5Bitz)
Having read my history and ‘building a performance miata’ by one of the guys from flyin’ Miata I’m very confident that supercharged is the way I want to go, low down torque and linear progression is what I want really.
It just astonishes me that the super charger unit from an old Cooper s can be bought for £500 or less but a kit can easily be between 5 and 10 times that which I don’t quite understand.
The large majority of the price is likely to be on buying the replacement ECU, from my own investigations, then the setup / dyno time.
In theory, a very basic, hot side installation can be done in a day on your drive. Worth considering that if you go very simple indeed, you can get away without much in the way of adjustment on the control element, which keeps the cost as low as possible. I saw a recent post on FB, from a reputable company, with kits for £1200 all in. I’m just wracking my brain box to recall who it was! 
Bofi probably is the best option but is £4K when you can pick up a second hand super charger for about 10% of that. I definitely want the lowest stress, most reliable setup possible as I intend to use the car driving Guildford to Bristol and back to see my son.
Found it.
Well worth a read through, even if only for information to help your own plans, since it’s so close to your stated plans and comprises a fully qualified shopping list.
https://www.facebook.com/425877840776204/posts/4281606285203321/
1 Like
Wow I would love to hear who is offering that kit, please let me know if you remember!
With the bofi kits priced at about £4K before labour seems pretty hefty. Also I won’t be doing the work myself as whilst I understand the theory, I’m not sure I would trust my handiwork for long distances and I need the car to be able to do 300 miles in a day regularly to get to Bristol and back as I said above.
That looks perfect! Now I just need someone to install it for me. I have spoken to Colin but given that he seems too honest for his own good he has told me I’m better off getting someone to fit it who has their own rolling road for tuning as otherwise he would need to send the car away for tuning and the cost then jumps again.
We shall see…
I will let you know what I discover when I plug in the ODB2 tomorrow assuming Amazon prime is as efficient as they claim to be!
1 Like