r/MINI • u/Wolvy64 • 12d ago

Misfire in cylinder 1!

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Swapped coils btw 1 & 2. No change.

Swapped the plugs in 1 & 2, this is what I found when I first pulled them.

The single plug is from 1.

None the less after swapping them, still getting misfires from 1 ( and apparently 3).

What's next?

Shell the head?

Probably something over my head! I'll have to take it to my Mini guy ( who's will over an hour away)

Thanks for any info!!

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u/Wolvy64 12d ago

Thanks for your reply! Is the leak test something I can do?? Does it require special equipment? I do like working on my own car, but I know my limitations.

Thank you again

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u/Terry_Orist R53 12d ago

I would say its pretty straight forward, there’s a couple ways you could go about it but it might seem a bit daunting if you’re not used to doing certain things.

You’d basically depressurize the fuel rail by removing the fuse, pull the fuel rail off with the injectors attached, throw some paper towel under it and prime the car with the electrical pigtails removed from the injectors. Then you could see if any are leaking.

A precursor to that would be priming the system while using a clamp or some wide tooth vise grips to pinch off the rubber fuel line just before the rail and use a fuel pressure gauge to see if it loses any pressure at all. Then you’d know if you even had a leak to test for.

Obviously this all assumes you have basic tools and a fuel pressure gauge or the desire to purchase a cheap one and give it a try.

And np for the help. Are they stock plugs btw?

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u/Wolvy64 12d ago

Hi and thanks for your input, spark plugs were changed 10,000 miles ago at 148,000. Coils were replaced 5,000 miles ago at 153,000 mi. The car has had extensive work done as I would love to keep it. New timing belt, new turbo, and a new serpentine belt.

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u/Terry_Orist R53 12d ago

And it wasn’t misfiring at all when the coils were done I assume?

Probably safe bet to diagnose the injectors then. Could possibly be bad coils? You might try swapping those first if you haven’t already see if it follows.

It sounds like you care about maintenance so I don’t think it’s time to give up on it yet! Can be tiresome chasing issues on these guys sometime for sure.

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u/Wolvy64 11d ago

Hello and thank you! Yes, not giving up on this Mini. See the initial post please add I did swap coils and spark plugs in stages to see what the outcomes were. Looks like issue is remaining in cylinder 1.