hey all i was hoping for some ideas, the 4k in my ke70 wags has decided it doesn't want to fire on cyl 3 and 4. I've checked the obvious things as I'm not completely useless i am an auto electrician but obviously not useful enough to figure this out haha its got good spark compression is even across all cyl has new plugs leads rotor and cap there is some kind of gas escaping around the plate on the back of the head obviously this isn't good haha anyway if anyone has any ideas throw them at me.

 

thanks james

Gas escaping out the water pipe/plate at the rear of the head would indicate a compression leak? So a cactus headgasket and/or a cracked head.

 

Take the radiator cap off and see if it bubbles when the car idles. Take the plugs out and dip some paper towel into the cylinders to check if they're full of water.

3 and 4 lead around the wrong way if you changed them before it started playing up.

i am an auto electrician but obviously not useful enough to figure this out

 

thanks james

 

I'm a auto electrian too, please don't bring shame to our trade by asking questions that you should know the answers too, :)

i only asked because the compression test came up fine stupid unreliable pistons 12a time

As the others guys have said,

 

Check the firing order, 1.3.4.2, and i would do a cooling system pressure test, if you know any mechanics borrow theres, (being in the trade you should know a few), pull the sparkplugs out and check for water/coolent in there, maybe spin the engine by hand to get the pistons to the top to make it easier. if thats all clear and like you said the leads, plugs, rotor and dist. cap and compression are fine, and assuming its not a twin carb, or it has a major air leak on 3 & 4 or some how it swallowed a rag and is stuck in the manifold in runners 3 & 4, then it only leaves 1 thing, and that is swine flu!

 

Basically, Air, Fuel, Compression and Ignition,.