guku0701

after having alot of trouble with bad misfiring i changed my plugs and wires and found oil on top of the spark plug(not the threads).can ran real smooth and no hesitation during acceleration for a while.after 20 mins of driving the hesitation is back.what could be the problem?do you think oil is sweeping back into the plugs and causing a misfiring?

help will be greatly appreciated

MDSC

iTrader: (3)

If its on the tip where wires go not huge problem just.valve cover gaskets if.its on the tip that's inside cylender itself you got.issues valve seals or piston rings or.combination of both

Mr.1.5

I had this issue with my 93 5spd and it ended up being the valve cover gaskets as MDSC said.

guku0701

u guys think its because of the oil that im getting the misfire?i really hope its the valve cover gasket..is there a diy here?
thanks for the replies

guku0701

so if i have a litle bit of oil on the threads that would be piston rings?

Ali SC3

iTrader: (10)

do your valve cover gaskets look like they are leaking? thats usually the problem, and yes it will get on the plugs and slowly make its way down the threads and misfire if it pools up for long enough.
so oil on top of the plugs in the spark plug valley = valve cover gasket
oil leaking into the cylinder from inside the head = valve stem seals

so change your leaky valve cover gaskets, then change your spark plugs.
https://www.clublexus.com/forums/per...ning-tips.html

guku0701

yes my valve covers seem to be leaking.and i just checked my plugs and i found traces of oil in the threads too.but i didnt find any oil on the prone.it seemed clear but worn out.im really hoping its only the valve cover gasket.thanks for the info.

Ali SC3

iTrader: (10)

The part that misfires is actually the top part of the plug where the wire connects. The oil collecting there makes a good path to ground (engine block) from where the plug connects. you get a misfire because the spark never made it to the motor. So if the top of your plugs are still there, you could clean them off.

But, a valve cover job on the 2jzge requires taking off so much stuff its worth it to just change them unless they have already been replaced recently. You will not want to do it over again if you have an issue. you can put Iridium plugs in there and be set for a very very long time.

This is a very common thing though, its like Toyota designed the valve covers to collect oil in the plug valley.
You will also notice your car running better after you fix it because the crank case has metered air running through the pcv system, if you are leaking oil you are leaking air, so that will be an added bonus from fixing it.

guku0701

i just checked the spark plugs after 2 days of hesitant driving.there was no oil at all.the top end where the wires connect had a white grease kind of thing which i think came with the new wires i put in.the plugs seem a little over worn out.i only took 4 on one side of the engine.this is a 1UZFE btw.
i have attached a picture of the spark plug after running for 2 days.does this look normal?

guku0701

another pic

guku0701

another showing the top end

guku0701

if these look normal should i try changing the dist rotor and cap?im really confused any help will be greatly appreciated..

MDSC

iTrader: (3)

change your wires make sure you dont cross wires, look up firing order and place wires in the right place on cap and cylender number. Replace cap and rotor yes i would do that also while you in there.

shivan0124

Changing distributor cap and rotor is a simple yet cheap fix. Wouldn't hurt to have it replaced anyway

guku0701

i changed the cap and rotor today..my car runs real good right now after i take off the maf sensor..when i connect it kind of bogs down at load.once when it happened i checked my wires and one of them was lose so i tightened it.it was good for a while but started again.does any one have luck putting in aftermarket plug wires?i already chaged my maf sensor but not the housing.is there any way the housing can go bad?i mean the mesh part in front?