Lost A Cylinder

[cefiro]

Hey guys just trying to work out whats wrong with a mates RB20. We cant get cylinder 6 (closest to the driver???) to fire. swapped plugs, coil packs. Its not fireing as it makes no difference to the engine rpm and sound if its plugged in or not so its def dropped that las one. The only thing left to do is swap a PTU but mine isnt interchangeable with his. Is there anything else left to check for?????

Would a compression test reveal anything, but surely even if its compression is stuffed then it could be down on power but still fire???

[danielson]

if there is a severe lack of compression the fuel wont atomise and wont ignite, it will just flood that cylinder.

drop the plug and check its colour, while your there compression test... should be around 160psi i believe

[TurboX]

Definately need to do a comp test. If its way down it wont fire.

My RB20 blew through the head gasket into the water jacket as the water had corroded under the HG to the steel ring and rusted it out from behind on number 6.

The comp was down about 10 PSI from 120 on rest of them but was still firing ok though prior to blowing full pressure into cooling system and blowing an impossible to get at hose out at the Calder Drags.

Whatever it is, it sounds not good.

[SECURITY]

grab a clean cloth then shove it down the #6 spark plug hole (use a screw driver to push it down if you like). pull it out and check if its just fuel thats in there.

any signs of oil and you've done one of your rings.

check if hes blowing blue smoke which is another sign of damages rings.

[R31Nismoid]

could be the igniter pack itself has shat a resistor or similar

tried swapping that over?

[RB30-POWER]

Have you pulled the plug and coil out and actually checked for spark whilst its running?

Have you compression checked the cylinder?

Have you connected a noid/led test light to check for injector pulse?

If its all sweet, my guess is a plugged injector and will need replacement. (rare problem though and im sure you will find the fault before you get to this stage)

[cefiro]

Yeah my friend got well electricuted when we started the car with the spark plug out, kicked it over anyway. we checked the pulse of injector with the old listening to the screwdriver on the top and it was ticking fine.

So I guess its just down to checking compression and going from there.

Cheers everyone