Cutting out when cold

[mx5ash]

I was talking to fergus today and he said that you can swap out his ecu to eliminate that aswell. I also have a spare one here if you need it. Ash

[K10]

Cheers Ash.

And thanks Fergus - legend - standing in the rain, offering me various bits of his car to test out.

Never got to the ECU, too wet, will have to try it and also a coilpack, one of those hopefully. Will test the coils tomorrow with an ohmmeter.

Ordered new leads and plugs, existing items are both new, but no harm to give it a go. After that, I'm going to drop it to O'Briens in Midleton, I've spent too much time on this and just want to drive it.

[Steve]

If you need to borrow a coil to test, send me you address via PM and I'll stick my spare one in the post to you.

Steve

[rustynuts]

Hi im a newbie here, im registered on mx5nutz in the uk, ive got the exact same problems with my eunos, its driving me mad too, ive done more or less the same as you with no luck, now its started to give out loads of white smoke on startup, its not overheating and the compresion is good on all cylinders, Iwas thinking water in fuel,maybe from an old fuel filter, my cars an 89,probably the filters never been changed,
Anyway ive just bought a doner car which runs ok but has been crashed, im going to gradually change components over untill i sort it out,i,ll keep you posted if i have any luck ,(check my posts on the mx5nutz forum--same avatar ) cheers

[K10]

Cheers - looks like a similar problem, you haven't changed your coilpack either. I'll do the leads and plugs tomorrow and then the coilpack.

[rustynuts]

yea ive changed the leads and plugs on mine, but not the coilpacks,didnt make any difference to mine,good luck

[K10]

Latest update - potentially good news...

Went to Fergus's today. We swapped the leads and coilpack. Seemed to make a small difference - the only way to see is to swap it long term, and try it from cold.

Swapped over the ECU also, no difference at all. At least we're ruling things out. New leads and plugs arriving from MX5parts tomorrow, will get a loan of that one from Srigley.

Cheers all, seems like we're getting there.

[Fergus]

I'm starting to think..... injectors, fuel pump, valves or vavle springs

[K10]

I'm starting to think..... injectors, fuel pump, valves or vavle springs

Hopefully not...

I'll replace the coilpack first, seems like that's the cause (I hope).

[K10]

Getting worse, which is a good thing I think - the car refused to start at all this morn. Seems like the cylinders are getting fuel, since the smell from cranking it was strong enough, it seemed to fire on one or two cylinders every 5 or 6 revolutions.

Waiting for the coilpack from Srigley, and the leads and plugs also haven't turned up yet. Replacement should tell straight away if they were the problem.

Fingers crossed.

[Steve]

coil in the post

See if you have any spark by putting a spare sparkplug on the end of one of your ignition leads then leave it on the camcover to ground it, you should see a spark when the engine is turning over (just do it once or twice). If not, this will confirm coil/spark issues. It should be a prob on either 1 & 3 or 2 & 4 (they fire together).

Also, open the oil cap and have someone turn the starter over, see if your cams are moving.. if not... your cam belt has gone.

[K10]

coil in the post

See if you have any spark by putting a spare sparkplug on the end of one of your ignition leads then leave it on the camcover to ground it, you should see a spark when the engine is turning over (just do it once or twice). If not, this will confirm coil/spark issues. It should be a prob on either 1 & 3 or 2 & 4 (they fire together).

Also, open the oil cap and have someone turn the starter over, see if your cams are moving.. if not... your cam belt has gone.

Not the cambelt - she is turning over normally.

Will do with the spark plugs - was thinking that it just may be a weak spark on 2 cylinders, down to the coilpack, and may have just deteriorated to the stage where the engine won't catch now.

Thanks again for the coil.

[franksm]

hopefully it is the coil ! If two out of four cylinders are misfiring, then it ought to be.

One last thing to think about if it isn't that: the crank pulley can go bad after a while, which screws up the timing on the car - almost the same as if the cambelt has jumped a tooth or two. The crank pulley is a 'balancer' of some sort, a sandwich of two metal plates with rubber in between, and it's the rubber that goes bad.

http://forum.miata.net/vb/showthread.ph ... ank+damper

[rustynuts]

got the doner car on saturday,and changed the plugs, leads, coil packs, and afm, ---no difference ,moving on to the throttle body area next, i,ll keep you posted

[NickD]

I have not read all the posts, but you know there is a wax operated fast iddle in the throttle body, I would suspect that has a lot to do with it.