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Hi all,


Trying to find a misfire in my freshly rebuilt rb26.


The car misfires from idle to 3000rpm ish (haven't taken it higher)


What I have done to pinpoint the miss is


Unplug each coil pack (the exhaust note changes with each one unpluged)


Unplug each injector (same results as coil packs)


New plugs


New Crank angle sensor


Compression test showed all 6 cylinders even (148psi)


Sprayed carby cleaner around the place looking for vacuum leaks


Injectors have just been professionally cleaned


Unplugged the air flow meters. Car seems to idle smoother but misfires the same once I build revs up a little.


Not sure where to go from here?


Advice appreciated!!


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You should try changing the coils. Just as a process of illumination. Check injector plus make sure thats fine with a node light. Should be one of those. Last resort could be a broken ring. Need to do a leak down test. Wit broken ring its tricky. I had one years upon years ago but had compression.

Cheers for the replies.

I should mention the issue started after it was assembled then went away. It had it's time on the dyno and has started playing up again.
The motor probably has about 50kms on it.

The Valve seats where cut. I'm using Tomei Type B springs.

Timing is spot on.

Going to try igniter and coils packs from a mate.

Cheers

What I don't understand is why I can't pinpoint the missing cylinder via unplugging the coil packs 1 by 1.

cause of its valve springs it will be all cylinders

There was a thread only a month or so back where he had a missfire issue on a built engine and it turn out to be springs, also have seen it on about 3 other cars

  • 2 weeks later...

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