Cutting out when cold

[K10]

I replaced the complete throttle body complete with ICV. No effect.

Waiting on that coil pack - hopefully today.

[Steve]

let me know when it arrives.. should be with you today

[K10]

Bad news.

Srigley, I swapped in your coilpack today, no good, making a cracking noise - I presume this is tracking of spark across the pack, I think it's no good.

I replaced the plugs and leads also, and no good, a possibility that it is the coilpack still, will try to borrow Fergus's one again and see, after that, I'm going to give it to a mechanic, before I'm tempted to set the thing on fire.

[Steve]

Gah! Give the 3rd coil post from the left a clean plus a little bit of WD40 (its been sitting in the damp shed for a bit).
Def try another if it continues..
So, did the car start? Did it idle ok? Didn't the car die on you last Fri?

[K10]

Last friday, I couldn't start it at all, plugs were badly fouled form that, changing the coilpack did nothing, so I changed the leads also, nothing, then put in the new plugs and it coughed into life, very reluctantly.

Idled, then cut out, started with a bit of winding and then ran as before - badly.

Will give the coilpack a clean tonight and give it a go.

[leamyj]

By this stage I'd have torched it and called the insurance company

John

[NickD]

Of similar problems I have heard, the end results were a missing screw on the twin Webber set up.
In the other case it was a burnt valve.

Are you sure your timing has not gone to pot?

[Steve]

I can't remember, have you checked that all the rubber nipples + bungs are on the intake manifold? One on top near the front, one at the back of the manifold (hard to see). Its the one above the word "dash" here :

Also, did you change your fuel filter? When its running rough, can you get it to run at 2kRPM ok using the accelerator or does it die?
Yeah, give the coil a go, also check + clean your ground points (engine to body + the 5 grounds that go to the bolt under the windscreen washer fluid bottle).

Steve

[K10]

Have checked the manifold over with a piece of hose in my ear - no leaks, even at the back.

Filter changed. Will run OK above about 3000 revs, haven't checked the earths, but I will.

I have found a decent mechanic who loves MX5s, dropping it to him next week. Hopefully...

[mx5ash]

Who have you found out of interest?

[Geese]

Am I right in saying that if the car is stone cold it wont drive? Does it idle correctly? Does it drive ok when warm?

Firstly which model Roadster is it? Are there any modifications dont to her?

I don't think it's the coilpack/ sparks (unless you have very cold/old plugs) If crank sensor is off then it wouldn't run right at all, if the Tbelt is off the same.

Assuming the car drive fine when warm has to do with Cold Start sequence or the Warming up IG timing or fuel enrichment phase.
If ECU has been changed and there's no difference then it has to be sensor(s).
Either water temp sensor, IAC or Air temp sensor.
It might not be the sensor at fault it could be the connector/ wiring

[Steve]

just fyi, no air temp sensor in the early mk1 (no sure if it was added later tho).

[K10]

Who have you found out of interest?

Ray Lane - Top of Sarsfield Road (only a few hundred yards from my house. He's done a lot of work on my Audi, so will see how he gets on with this.

[K10]

Am I right in saying that if the car is stone cold it wont drive? Does it idle correctly? Does it drive ok when warm?

Firstly which model Roadster is it? Are there any modifications dont to her?

I don't think it's the coilpack/ sparks (unless you have very cold/old plugs) If crank sensor is off then it wouldn't run right at all, if the Tbelt is off the same.

Assuming the car drive fine when warm has to do with Cold Start sequence or the Warming up IG timing or fuel enrichment phase.
If ECU has been changed and there's no difference then it has to be sensor(s).
Either water temp sensor, IAC or Air temp sensor.
It might not be the sensor at fault it could be the connector/ wiring

Pretty much won't drive when cold, will cut out when first put under load, or not long after. Will start again with a LOT of cranking and then will cough and splutter for a while, eventually settling down, but never running what you would call smoothly or developing as much power as it should.

Engine and management system are 100% standard.

It could be a sensor, wiring, earth point, ignition timing (due to cam sensor, I have checked and rechecked the cam timing).

Agreed, it may be the wiring also, but I don't have the expertise to figure it out I think.

[rustynuts]

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.

ive got the same problem,but just recently its been acompanied with lots of white smoke on startup,then it will clear and run ok, ive changed the wax operated unit today,and on starting it didnt smoke or cut out, just an idea but does anyone know if the water inlet to this valve could bypass a seal and enter the plenum chamber causing the car to smoke/stall on idle untill the engine warms up, just an idea,please let me know if im talking b***ocks
what do you think folks