Ady B

Hi,im new to all this but i have a classic wagon and it keeps getting a missfire after ive put a new set of plugs in,im using the ngk pfr6b firstly and after 42 mile it killed them and then i upgraded them to ngk pfr7b and it ran great then same again its back to a bag of hammers any help thanks

maca1983

iTrader: (3)

Any fault codes showing up?

Have you checked the plugs are still ok?

Ady B

No fault codes.
First set of plugs when tested 2 p[lugs with no spark thought they may have been faulty so i replaced them withnew rb7s that i had for the engine i am rebuilding for my other scooby. They worked straight away engine running lovely. Used it for around 20 miles same thing happened. Havent tested the plugs yet. It was running ok before i changed the plugs in the first place.

maca1983

iTrader: (3)

What scoob you got??

Coilpacks are prone to degrading on classics, have you took the rubbers off and checked the tips for cracks?

Dmacnz

Hows your O2 sensor? Does the car smell rich? Plugs could be fouling up

winston69

iTrader: (30)

My money is on the HT leads

winston69

iTrader: (30)

And don't replace with any magnecor aftermarket rubbish, get some genuine replacements from Import car parts

alcazar

iTrader: (2)

Check leads as above and replace, as above

Check mixture.
Check engine codes.

Tell us what mods the car has, and if it's been mapped for them.

Ady B

It is a 95 WRX standard apart from a cone filter someone as added. The plugs look ok apart from wet with petrol on a couple from the misfire on the rear two pots. When car was running well also had hesitation when putting your foot down.

alcazar

iTrader: (2)

Does sound like it's running rich.
Not even a VTA dumpvalve?

maca1983

iTrader: (3)

Have you got any further with this??
I had a problem with hesitation/missing/running like a bag of **** on boost and it turned out to be a cracked coil pack, on one previous issue this (below) turned out to be the problem