1989 240SX Fastback KA24E SOHC Continious Misfiring Problem.

[puerkone]

Hi I have a 240SX with 150000 miles in it. I just recently changed the water pump, thermostat, radiator hoses, belts, spark plugs, wires, distributor cap and rotor, fuel filter and o2 sensor and now I have this misfiring problem. When I first started driving the car with all this new stuff, the car was running pretty good then a day later the car started to misfire. The car runs fine below 3000 RPM when cold and when the engine is warm the engine starts to misfire at any random RPMS. So I removed the spark plugs and they were all burnt up with white dust on them and for some reason the electrodes on the spark were bent and broken. So what could possibly make this problem? any help please? By the way I tried NGK & Autolite XP Spark Plugs. Please someone help me. I need my car for school and commuting. Thanks.

[puerkone]

ok here are the pictures.

Note: These both sets were brand new NGKs today and when I drove it to school I removed them and thankfully I had a set with me so I replaced them overthere and when I was on my way back home it started misfiring again and when I pulled them out they came out burnt and regapped and the car sounds fine and runs really good when they are brand new why does it do that?I can't figure it out.



Is my timing ok to be all the way to the left on the distribuitor?

I just put these new spark plugs today and when it misfired today now they look burnt whats going on its like the plugs are running too lean or what? please help me. NGK Spark Plugs. Both sets of plugs gave up on the same day

Cylinder 4

Cylinder 3

Cylinder 2

Cylinder 1

Burnt Sparkplugs

the set before I put these plugs were worse they were burnt and broken





Same thing they were burnt any help? I gap them all at .044 and when i pull them out the gap changes below .020 why does it regap by itself? help!!!

[aris_unlimited]

Are you positive that you have the right spark plugs? Your pics are kinda fuzzy so hard to see in detail well, but are there marks on the plug like something is tapping it, to close the gap? Have you looked into the plug holes to see if anything has fallen down into the cylinders?

**edit**

Also you say the one set of plugs were burnt and "broken". What do you mean by broken? If pieces fell off, then you need to get into your cylinders and remove any debris before it scratches up your cylinder walls and ruins your rings.