Hey guys my worked 4k aint firing properly on cyl 2. i hav swaped plugs around, got new points and condensor, new leads, checked valve clearances and set timing to 12 degrees btdc. all the other plugs are overrated but no 2 keeps fouling.i am gettin a new dizzy cap and rotor today to.

what the shit is going on?

oh and have also done compression tests and leak downs and there overrated

Oil ring broken?? Oil fouling or fuel do you think?

 

OK, leakdown & compressions all the same, so comp rings, head gasket and valves fine, and cam working properly.

 

Plug and lead changed, so they're OK.

 

The dizzy cap might have a tiny crack by No 2, so today will sort that one.

 

Not much else can affect one cylinder and not the next.. Good luck!

yeah hopefully will be the dizzy cap otherwise i have no idea. don't think its oil as it hasnt used any oil and the engine has had a recent full on rebuild...

rev it and when you let it off check if any smoke comes out the back, if it does then there might be a leaky valve seal

if it leaks oil under hard accelleration then it would most probably be the oil ring on no.2

 

if anything is leaking you might as well do some headwork while its off :)

already had work done to the head. ported nd polished. I'm running a 3k coil and ballast resistor and also the 3k dizzy this shouldnt affect it though right?

why a 3k dizzy? arent 4/5k a better option?

but no id imagine that wouldnt effect it unless it wasnt firing properly due to cracked contact, measure the resistance between the lead side and the rotor button side, it should be no resistance, if its not then buy new cap

bought the new dizzy cap and rotor, cleaned the plugs and swapped them. drove it home and the plug is fouled.....

the reason i have the 3k dizzy is because i took it off my old 3k. when i bought the 4k it was only the engine and nothing else..

checked valve clearances on all cylinders and there overrated too... could it be my twin carbs? there original toyota k series twin carbs with matched porting to the cylinder head

remove number 2 lead and stick a screwdriver in it and earth it on the rocket cover and increase the gap between the screwdriver and cover till the spark goes out then check if its the same gap with cylinder 1 3 4

could it be my twin carbs?

 

Shouldn't be, that would affect cyls 1 and 2 together. or if there was a manifold leak to number 2 it should run lean.

 

Can you hear it misfiring occasionally on #2? If its electrical then it should miss a cycle completely and you should feel that. If its running rich or oiling up it may not actually misfire until it fouls the plug enough.

turns out it was the front carb....put a another carb on and now its overrated! now the rears can really spin :P

Well done!

 

Something to tuck way and remember..