2.3 Misfire

[chicosi]

My wife's mk1 99 2.3 DOHC Galaxy started running roughly on Friday. Other commitments meant I couldn't look at it until yesterday afternoon. When I started it, it ran ok for a few seconds then started runing on 3, maybe 2 cylinders. A quick search on here indicated duff spark plugs/HT leads/coilpacks.

 

Took off the cover and a quick inspection found everything in good condition, remarkably fresh with no corrosion or dodgy looking wires. Running in low light didn't reveal any arcing etc. Car has done 70,000 and there's no reason to suspect that they aren't the original leads.

 

Next job was to remove the spark plugs, first 2 were in good condition, however on removing no. 3, the gap was almost completely closed up. Reset gap, took out no. 4 which seemed ok and put everything back together.

 

When I started her up there was a loud tapping noise which stopped after 5-10 seconds then she sat idling no bother. Decided to go for a test drive but only got a couple of hundred yards before she started running on 2 again. Towed it back to the house and on removing the spark plugs nos. 1 & 4 were wet with petrol. Gap on no. 3 was ok. Spark plugs have done 15,000 miles at the very most

 

Questions/opinions please:-

 

Why had the gap on no. 3 closed up?

 

What was the tapping noise (tappet?) and did this have a connection with no. 3?

 

As said, everything looks remarkably fresh, Can the coil packs break down with no outward sign of cracks etc? As 1 & 2 share a coil as do 3 & 4, 1 and 4 being wet suggests that either both packs are duff or something common to both is wrong, which is it likely to be? Edit: It's actually 1 & 4 and 2 & 3 that share coils

 

Is 70,000 miles a reasonable life expectancy for the leads/coils and am I best not to renew components in stages but just bite the bullet and renew everything including plugs even though they look ok?

 

With regards to cost, although I can't get prices from my usual motor factors until tomorrow, having a look at what I can find on the internet suggests that 2.3 Scorpio parts are cheaper. As far as I know the engines are the same, so is there any reason I can't use Scorpio parts?

 

Thanks for looking :16:

[Guest BagPuss]

Had a similar thing happen on my Cinq Sporting.

 

That seemed to be running on 3 Cylinders, no power etc, Well come on it's only 54BHP to start with! :16:

So I did the same checks, only 1 spark plug was wet whereas the others were all ok.

 

My Cinq had twin coil packs as well, initially I thought Head Gasket, but after sticking it into the garage it was indeed a Coil Pack gone.

 

So it might in deed be that.

 

 

As for the tapping, mine does that and then it goes once the oil has circulated.

[El Dingo]

Check for sparks!

 

Plug 3 gap could have closed due to electrode dropping down inside the ceramic??? Normally plugs erode and the gap gets bigger, not smaller. Otherwise mechanical damage; most likely it was put in like that... (no offence, if you installed them yourself). :P

 

It does sound like a coil pack. :16:

[sepulchrave]

Sounds like the leads to me, the problem got worse after you'd disturbed them. I'd replace all four then see if you need a coil pack.

 

As regards plug number three the muppet who fitted them probably dropped it whilst replacing them and didn't bother to check it with his thumbnail. :16:

[chicosi]

Put the car to a garage as I didn't fancy forking out

[Andrew T]

In the absence of anyone more qualified answering, I'd suggest you gamble

[chicosi]

Got the car running enough to go for a drive in low gear at high revs (apparently the valves start to spin above 4000 rpm and speed up the cleaning process)

 

When I got back it was better but still misfiring, removed the plugs and the gap in no.4 had closed right up!

 

Adjusted gap, started her up and she was revving and idling fine. Didn't go for a drive as the wife was working and didn't fancy being stranded with three kids if it cut out again.

 

It's perfectly possible that I'd put the original no.3 plug back in no.4 so I'm hoping that it's a duff plug. Although the gap closing by itself seems strange, the only other reason, of course, is that something's contacting the plugs in the cylinder and I don't want to even contemplate that!

 

I'll try a new set of plugs tonight and take it from there

 

Fingers crossed!