Hi,

just got home after a 6 mile drive from cold, with engine ticking over whilst waiting to drop someone home, when engine starts misfiring, on 2 mile trip it feels like 1 cylinder is cutting in and out. By the time I get back home it seems to be running on 3 cylinders constantly. I will have a look tonight to see which one is playing up, doubt it is a plug, has this model got seperate coil packs built in with the plug caps and if so do they play up or just fail completly?

Bob.

My money is on a failed coilpack mate.

:iagree:

If you're losing the cylinder completely it's coilpack(s); plugs are usually a misfire, and normally show up first at high revs/throttle.

My money is on a failed coilpack mate.

Thanks for your advice chaps, just gave it a short run, bringing it up to normal temperature and its running on all 4 at the moment, will give it a longer run later.

You can do serious damage to the cat on the exhaust running with a misfire......beware!! Unburnt fuel will $hag it!

Steve:)

You can do serious damage to the cat on the exhaust running with a misfire......beware!! Unburnt fuel will $hag it!

Steve:)

Thanks Steve, do the coil packs play up before they fail completely?

Thanks Steve, do the coil packs play up before they fail completely?

They can show signs of an intermittent fault, especially top end before they finally go.

Steve:)

Changed coil pack, still have misfire on no.1 cyl, swapped 1 & 2 coil packs, misfire still on no.1. Will have another look at it tomorrow afternoon.

Today I swapped 1&2 sparkplugs, misfire still on 1, also checked to see that I had a live feed on connector to coilpack with ignition on, (if no live feed, could be ECU apparantly), checked electrical connector on no.1 injector, seemed to be ok, looks like I will have to get it put on a diagnostic machine.

Had another look at it today, checking wiring as much as I could incase of short, had no.1 cut back in and out a few times then stayed runing ok, took it around the block, back to 3 cylinders, so I went for a ride on me bike!

Could it be the fuel timing on No1 then? You appear to have eliminated the HT system and ignition signalling, but a very early or late fuel delivery might cause a misfire.

Could it be the fuel timing on No1 then? You appear to have eliminated the HT system and ignition signalling, but a very early or late fuel delivery might cause a misfire.

A good point, I thought of fuel but not the timing of it. I had a look at the connection to the injector which seemed ok and when I swapped sparkplugs no.1 was wet. Someone has suggested a sticky valve but to me it seems electrical the way it cut in and out, when accelerating it was instantaneous when it came back in, then it would just go back to 3 cyls again and yesterday at one point when it was ticking over it came back in and out 3 or 4 times in quick succesion.

If No1 plug is wet, you've got either a fuel timing or quantity issue, or oil getting into No1 (only if the plug's oily rather than petrolly).

I give up, its going in the garage tomorrow! Its someone we deal with at work who's had the car in before so at least the labour charge shouldn't be too much, I will update when I know more.

Thanks for the assistance anyway.

Good luck bud, keep us updated!

Well, apparantly the fault was traced to the 'Ignition Amplifier'.

The part is approx £100 trade and I don't think its to hard to fit but I will find out more tomorrow as its on order and should arrive in the morning.

Car back and running fine. The failed part, (Ignition Amplifier), is fitted at the back of the air box and is roughly 50mm x 30mm and reasonably flat. Apparantly failure is rare and the later models do not have them, mine is June 2000, last of the first model, Other than siezed rear electric window cables/motors, (which I've still to sort), thats the first problem in over 5yrs and 48k so can't complain.

Glad you got it sorted