sparking problem on my 4g63 HELP HLP HELP

4G638U · Post by **4G638U** » Tue Sep 08, 2009 5:27 am

Hey guys, ive just finished putting a 4g63t into my ex lancer and im having a problem with my spark. when i turn the engine over 2 spark plugs are sparking at the same time. the inner 2 then the outter 2.. can anyone please tell me why its doing this?? ive checked all grounds and power and they are fine.

Bill Hincher · Post by **Bill Hincher** » Tue Sep 08, 2009 9:45 am

thats how they are built,
the crankshaft is a flat 180 degree crank, that means the 1&4 cylinder are on the same stroke, and 2&3 cylinder are on the other stroke, one spark will be wasted per revolution because it fires on both on TDC when the exhaust valve is still open and also when the piston is on TDC after combustion stroke

4G638U · Post by **4G638U** » Wed Sep 09, 2009 3:55 am

How come its popping back out the inlet manifold??? ive done the cam belt 3 times now and its perefect.the the head has had a valve grind and ive checked all valves and they are sweet.

Bill Hincher · Post by **Bill Hincher** » Wed Sep 09, 2009 9:25 am

either your spark plug is firing when the intake valve is open
( Cas 180 degree out)
or you have a large vaccum leak in the intake maifold

734g63tsprite · Post by **734g63tsprite** » Fri Oct 16, 2009 2:38 am

Or your firing order is wrong. Happened to me. If you have an evo 3 intake manifold dont use the stock plate numbers!