Missing under load.

[Neil Fletcher]

My wife's MX5 has started to miss slightly under load, it only happens below about 2200 rpm if you try to accelerate quickly under load. It's not noticeable with light load or light acceleration and it disappears completely once you hit about 2200 rpm and runs fine at higher revs. Any pointers on what might be the trouble.

Thanks, Neil.

[MX5Spares]

Coil for sure .We have some but about 10 different types, what year, engine size ?? and any chance you know how many wires are going to it. ph no; 00353 86 8226506.Robert

[sidewaysreilly]

What Car is it?
The ignition needs to be load tested to rule out Leads first.

[Neil Fletcher]

It's a year 2000 1.6 - the strange thing is the cars runs perfectly over 2200 rpm without any miss or any other issue, in actual fact pulls like a train once she hits 2200 rpm. In actual fact under light load and light accelerations she is fine under 2200 but it's just if you try to accelerate hard at low revs she'll miss and hunt until she hits 2200, my wife usually ends up dropping her a gear and flooring her and she'll be fine. As I say the strange thing is she's fine over 2200 rpm.

Funnily enough I never thought of the coils as I was thinking more fueling issue or a sensor giving a faulty reading to the injection, certainly if the BDA in my Mk1 Escort was behaving like that I'd be looking at a partially blocked jet or some such.

Robert, you fitted one replacement coil to her a couple of years ago one day that my wife and I called down to visit you on one of our weekend trips away. She's a year 2000 1.6 and the plug goes up into each coil from below - 3 pin I think.

All the best, Neil.

[sidewaysreilly]

I would have thought the Ignition would break down under load above 2500 (max torque range) . I would get a spark test done all the same to rule out Leads as they are a known weak point and will shag a Coil very quickly. Bad plugs will too.