MX5 (1999) Not starting

556 Views 14 Replies 6 Participants Last post by Garffey, 5 mo ago

NACFC

Discussion Starter · 5 mo ago

Good evening all - I am hoping that someone can help me with a starting problem on my 1999 MX5. It has done 60,000 miles and had the belt changed a year ago.
I hadn’t used it for a month (this might not be relevant) and it started and ran for 5 seconds and then stopped. It fired a few more times and then stopped firing.

I replaced the fuel filter (probably for the first time by the look of it!) and whilst the pipe was off I cranked the engine to confirm that the fuel pump is working!

Having reassembled everything the engine fired for a few seconds and then would not fire at all.
I took number 1 plug out again and I am sure that the coil must be ok as I was holding a spark plug (with rubber gloves on). Was turning the engine with no spark - then a very weak intermittent spark - suddenly the spark was good and car started and gave me one hell of a belt through the rubber gloves!
Put the spark plug back in and the car started and ran well for nearly a minute. Then it stopped cleanly without warning - and now no spark again!
Anyone any idea why there is either intermittent or no spark at the plugs?

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Pat

· #2 · 5 mo ago

Hi NACFC a warm welcome to 'life' 🖐

sadly i am not to clever with engine problems

but i am sure someone will be along soon that will be able to help

in the meantime why not pop over to the new members section and tell us a bit about yourself

so we can all say hello properly 🙂

NACFC

Discussion Starter · #3 · 5 mo ago

Pat said:
Hi NACFC a warm welcome to 'life' 🖐

sadly i am not to clever with engine problems

but i am sure someone will be along soon that will be able to help

in the meantime why not pop over to the new members section and tell us a bit about yourself

so we can all say hello properly 🙂

Thank you for the welcome Pat

Kev5

· #4 · 5 mo ago

Hi again, NACFC 😄 Although I'm no expert on the Mk2 (NB) your problem does sound like a faulty coil pack, especially with those symptoms of weak spark, then very strong spark, coupled with the intermittent running.

The most effective way to diagnose the problem is to plug into a OBD II code reader and go from there. That should pin-point the problem and save further frustration and unnecessary expense.

Good luck and please keep us informed of any progress...oh, and Merry Christmas to you and yours! 😊

Reactions: 3

NACFC

Discussion Starter · #5 · 5 mo ago

Thanks Kev - hope you have a great break too.
My MX5 looks like it’s pre-OBD2 so it looks like I will need to check the diagnostics by linking terminal 10 to ground in the engine bay box (then check the flashing lights on the dash)
Will feed back in with any progress
Nigel

Reactions: 3

boxerdog1

· #6 · 5 mo ago

Agree with Kev - does sound like a coil pack issue NACFC . Good luck with the diagnosis

Reactions: 2

NACFC

Discussion Starter · #7 · 5 mo ago

boxerdog1 said:
Agree with Kev - does sound like a coil pack issue NACFC . Good luck with the diagnosis

So the basic diagnostics on this car is bringing up nothing! Before I buy a new coil pack - Is there any other reason that I can check for the coil not being given the signal to send out the high voltage? Any sensors etc on this MK2 1999 model?

Garffey

· #8 · 5 mo ago

Hi Nigel....having noticed you said it's been stood for a month is the passenger footwell dry?...The ECU is stored near the floor and sometimes water can cause issues?
I found a thread on google with a similar case of no spark which turned out to be the MAS Sensor it has a 7 pin terminal block and it suggests that it should have continuity over terminals 3 & 5 only.... faulty units would have it across others like 3,4 & 5.
Might be worth looking into?

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Reactions: 3

boxerdog1

· #9 · 5 mo ago

NACFC said:
So the basic diagnostics on this car is bringing up nothing! Before I buy a new coil pack - Is there any other reason that I can check for the coil not being given the signal to send out the high voltage? Any sensors etc on this MK2 1999 model?

Not aware of any sensors but may be wrong . I think in this case it's just a process of elimination, perhaps initially checking the ECU as outlined in Garfey's post earlier and then a set of replacement coil packs .

Reactions: 2

NACFC

Discussion Starter · #10 · 5 mo ago

boxerdog1 said:
Not aware of any sensors but may be wrong . I think in this case it's just a process of elimination, perhaps initially checking the ECU as outlined in Garfey's post earlier and then a set of replacement coil packs .

Thanks to you both - I will check the ecu as you suggest. I have just realised that I have been doing something really stupid! Having not driven the car for a while I have been trying to start it many times - without the clutch depressed!! I hope that I haven't damaged something by doing this!!

Reactions: 1

Mark

· #11 · 5 mo ago

NACFC said:
I have just realised that I have been doing something really stupid! Having not driven the car for a while I have been trying to start it many times - without the clutch depressed!! I hope that I haven't damaged something by doing this!!

While it may be good practice, there is no need to hold the clutch down to start any MX5, up until the current Mark 4 / ND models introduced in 2015

Reactions: 2

NACFC

Discussion Starter · #12 · 5 mo ago

Still on the case with this. The fuel filter, plugs and leads have been changed as a matter of routine service and I have also changed the cam sensor (which only cost £14). The ECU area is all dry.
I am now looking to replace the crank sensor - is that does not work then I think the lack of spark can only be the coil pack or the ECU!
As the coil pack is divided into 2 packs, I am thinking that it would be unusual for both to go at once? - so am hoping the crank sensor resolves the problem (It was a bit dirty, where the car had been wayoiled!!

Reactions: 1

Garffey

· #13 · 5 mo ago

Oh the days when all you had to change were plugs points and condensors....as well as ensure the timing was right!...🤨

Reactions: 3

NACFC

Discussion Starter · #14 · 5 mo ago

Finally sorted - crankshaft sensor changed for £16.49. All service items changed and a cheap repair.
Running superbly - thanks to everyone for the comments.

Reactions: 5

Garffey

· #15 · 5 mo ago

NACFC said:
Finally sorted - crankshaft sensor changed for £16.49. All service items changed and a cheap repair.
Running superbly - thanks to everyone for the comments.

Great news! 👍....glad you got it sorted relatively cheaply.
Now enjoy & keep us updated on how you get on!

Reactions: 1

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