Heavy misfire

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New Member
Howdy all,
I have a 92 sc400 and the problem I am currently having is a very strong misfire and by my estimation roughly 4 are missing. The things I have replaced include timing belt, fuel pump, fuel filter, spark plugs, MAF, ECU, and battery. I have tested compression, coils, and IACV. Also while the engine is running there is no engine light.

I am thinking about changing out injectors, but other than that I am lost on what to try.

Thanks for all the help in advance!


Super Moderator
Staff member
Sydney, Australia
Normally a misfire and 4 cylinders affected is electrical.

I'd be checking each cylinder to work out which ones are bad.

That will point to one or the other distributors. From there you have the appropriate distributors coil and igniter to check.

I once had two cylinders down and they were fed by different distributors. I'd crushed two plug leads on the same head under the plug cover and the wires were earthing. Took a while to figure it out.

I usually check which cylinders aren't working by dropping a few drops of water on each header pipe. The ones that don't sizzle aren't working.