Missfire since changing plugs

[blaine]

I have just changed the spark plugs on my Puma this morning and I have noticed it now has a bad missfire under load. Any suggestions?? I checked the gaps on the plugs and they were all fine.

 

[Puma Babe]

Did you do them one at a time and replace the lead or is it possible you have mixed the leads up?

you could have damaged a lead when removing or replacing

 

[Midnight Blue]

Probably a silly question - are the leads on the correct plugs?

 

[quest63]

Possibly you set the gap incorrectly for your plugs, I have read different comments for different gaps for different plugs.

Perhaps you may not have the leads pressed down securely on the plugs or disturbed the connectors to the coilpack.

Perhaps you damaged an old britle lead

 

[blaine]

Leads are Definately on the correct plugs, I am wondering if it could be leads not on plugs properly

 

[ElDude at Allison Automotive]

The plugs may just be knackered...iv'e had a fair few from ford knackered from new...can only presume they've been dropped etc

check for cracks..

 

[stumc]

nowadays plugs come pre-gapped so just a screw in and go job so should be an issue there. you could have damaged a lead pulling them off.

 

[lloyd2002]

I'm also suffering this problem - hadn't thought that the leads could be an issue. Many thanks

 

[tuonokid]

Might be some other problem but I hope the plugs you bought were NGK. I wouldn't use anything else.

 

[Anonymous]

I've used Champion plugs and found the little bits on the ends which the leads clip on to, were slightly smaller then the NGK plugs, therefore the leads didn't fit on the plugs properly.

 

[tuonokid]

Many years of running motors has taught me that if an oily two stroke can only run on NGK plugs they must be the best. If I couldn't get hold of them, at a push I'd use Denso, never Champion or Motorcraft!

 

[TheVarix]

Some time ago, a mechanic changed my spark plugs and used NGK Iridium spark plugs. The car was misfiring a bit (running a bit choppy). Changed coil pack and no difference.

I called Tremona garage and they said they had had quite a few people with same problem using those sort of plugs. He suggested to use Ford Motorcraft ones as apparently the Puma is a bit picky regarding spark plugs.

I followed his advice and the car run perfectly!