Misfire and speedo dancing

[TimR26]

Got a really bad misfire and the speedo sometimes dances up and down when accelerating. Speedo problem started after the ABS and SERV lights briefly came on. Read that it could be ABS rings but my rears are oem and less than two months old.

No engine management lights have come on since the misfire started. Misfire seems to happen when engine is either under load or doing above 60mph. My spark plugs are two years old so is this the most likely reason for the problem?

Thanks for your help.

 

[TimR26]

I'm going to try some new spark plugs tomorrow. Are the NGK PFR6E-10 best? If that doesn't work is it worth getting uprated HT leads or should I just stick with oem?

 

[Matt@Stealthsport]

Have you spoken to JMS it could be the coil pack possibly?

 

[TimR26]

No not yet mate. Sparkplugs are two years old so probably best replaced anyway.

 

[cliosportap]

if the car shakes at low rpms when you give full gas it is probably ht leads
i dont think that plugs can make it

 

[TimR26]

Replaced the spark plugs and car is running fine now

 

[TimR26]

Bumping this as the misfire is back after the new plugs fixing it. Misfire doesn't always happen but when it does it's under load from 3000rpm onward.

Am I right in thinking only possible causes are the ht leads, coilpack or tdc sensor? Don't want to change parts unnecessarily so what is best way to diagnose the problem?

Cheers

 

[DannoTheGreat]

i'd say its the leads buddy, i had the same sort of problem

 

[172Ben]

I have some standard leads in the garage if you wanna give them a go?

 

[TimR26]

Ok cheers. Where are you based Ben?

 

[172Ben]

Crewe dont mind posting, depends how desperate you are?

 

[TimR26]

YHPM

 

[TimR26]

Thanks Ben for sending the HT leads they have fixed the misfire

 

[172Ben]

Awesome Thats good!

Cheap fix to!

 

[Fletcher]

Glad to hear it's sorted Tim.

 

[TimR26]

Awesome Thats good!

Cheap fix to!

Yes, you've saved me a fortune, thanks again for sending them so quickly

Glad to hear it's sorted Tim.

So am I! It had misfired a few times over last two months but I'd just ignored it until it got very bad this week

Don't know if its a placebo effect but I took the car out for a play this afternoon and it seems more powerful now

 

[TimR26]

My car misfired a couple of times today. I've changed the spark plugs then fitted Ben's spare set of leads and both fixed the problem temporarily. Any suggestions for what I should do next?