Spark plugs & misfire

Hi guys

My car has been suffering from a slight misfire as the engine speed increases from idle. I decided to change the plugs, The ones fitted were NGK BP7EFVX. To be fair they looked ok when I removed them. The new plugs are NGK BKUR7ET. These plugs seem to have the same reach however when fitting them they did not seem to screw in as far. I counted about 7 turns before they became tight, whereas the old ones needed about 12 turns to remove them. Am I missing something, or is this because the plug seats are different. Most of all is this ok.? I don't want to do any damage. Unfortunately the misfire is still there. I am going to try new plug leads next.

Thanks Paul

[BIG_MVS]

Moved from Website help.

Paul - The website help section is for website issues rather than car stuff.

As for the misfire how are the HT Leads looking? Are they old? I seem to remember someone saying run the car in the dead of night (pitch black) with the engine cover open and see if there are any electrical currents showing up which will tell you if the plug leads have had it.

New plugs are A610 not GTA .Old plugs I put in about 200 miles ago so should be OK

Thanks Lee. I didn't think they looked old.

Paul

I'd take the 610 ones out .Will check dims when in unit but they are taller and the GTA has domed piston ,610 flat .

Thanks Lee, I have already taken them out. Don't want to do any damage

Good.I've just popped some in a GTA head and it wouldn't have hit as perversely they don't protrude enough .Shoulder diameter is a lot bigger and bottoms well before the probes enter the chamber .That why you get less turns.Will take some pics .If you want to pop over just shout and we can do some tests,swap leads etc to track it down .

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That's great lee, thanks for taking the time. I want to come over but although I am retired, having recently moved house, the list of jobs goes on. Added to which, we are going away next weekend. Hopefully I will get a chance to come over before we go.

Paul