spark plug problems

3 comments

  1. imported post

    I once had the same problem . Diagnosis was that one of the carbs was uber rich and fouling a particular plug on start up / heavy choke. Removed of the plug,wire brushed,applied heat gun, replaced plug and fired up fine.As you say if it starts it'll clear in a few mins.Balance the carbs/ weaken mixtureand see if this works, also check choke isn't stuck on.

    Rolling road sessions on cars with high comp / tuned engines sometimes result in start up problems like this from cold, depending on where you take it.

    Hope this helps.

  2. Hi everyone

    Here's a problem for your collective minds. I have a 997 with 295 head, bit higher comp ratio, warmer cam and H4s. The problem is that the engine has a hunger for spark plugs. The senario is : engine runs sweetly for a few hundred miles and then when laid up for few days or possiblya week, runs on three cylinderson start up.If left runnning for a minute or two the final cylinder kicks in and all's ok. After a couple of times of this, only a change of the offending plug will remedy the situation. I generally use NGK plugs, but changed to Champion briefly and the problem remained. This all started with BP6ES andduring a rolling road session they were changed to BP7ES and still remains. The only clues I have is that if anything the engine is running slightly rich, but not so bad as to be really obvious, and the usual offender is Nr2, but not always.

    I look forward to some ideas!

  3. imported post

    Thanks for that, I had wondered about the possibility of overfueling being a factor. I will look at this when its not too cold and see if I can alleviate the problem.

    AMS

Leave a comment