Toyota Liteace 5K Engine Misfire

[Izzie]

*Chinoi

Yes. The spark plug in #3 is fouled. Spark Plugs for the other 3 cylinders are okay. I have downloaded a pdf file titled "MISFIRES" and according to it:

"If the plug is fouled, this is the reason for the misfiring, but you must still determine what has caused the plug to foul. Heavy, black, oily deposits indicate that the engine is burning oil. The most likely cause is worn valve guide seals and/or guides, but worn rings and cylinders can also allow oil into the combustion chamber. Replacing the spark plug will temporarily cure the misfire problem, but the engine will continue to foul plugs until the oil consumption problem is corrected."

Here's the thing, replacing the plug will NOT temporary cure my misfire problem because I get NO SPARK in cylinder #3 in the first place. If it has a spark and it get fouled, then I can consider that the engine needs to be serviced. (Catch22 perhaps? )

Do note the dry compression test came out okay.

Another type of plug fouling is:

"Carbon fouling, can be recognized by a buildup of soft, dry, black deposits on the plug. Carbon fouling can be caused by an overly rich A/F mixture, overly retarded ignition timing, too cold a plug for the application, or faulty ignition wires."

Will do a spark test tomorrow again. In the meantime lets enjoy the night by welcoming 2015.

Happy New Year to you and to all fellow members in Tsikot.com!!!

[dr. d]

Replacing the spark plug will temporarily cure the misfire problem, but the engine will continue to foul plugs until the oil consumption problem is corrected."
![/QUOTE]

doesn't anybody clean his spark plugs anymore? bakit replace nang replace, when cleaning them used to be the norm...?
ang-luho na ninyong mga bata, a...

[Izzie]

I clean my spark plugs. Gasoline, fine sandpaper, steel brush.

Back in the 80's I used to have the following items to tune up an engine. A timing light, dwell/timing analog meter, spark plug cleaner, feeler gauge, oil filter wrench and the Chilton's Auto Repair manual the size of a webster dictionary!

I only used these items twice before I started to work overseas. The Chilton manual is "the holy grail" of most makes/models of automobile then. It has everything.

All of these items are now gone. The last thing I know (1988), my (late) brother lent it to his (late) mechanic friend.

Whoever has it after is lucky.

[innova2013]

Have you tried using another known working distributor assembly? Possible the fairly new distributor is defective.

If the liteace is for keeps, invest to an electronic distributor. Your car will idle better, run better, and bump a little improvement to your fuel comsumption. I bought mine 5 or 6yrs ago at 3800pesos. Try searching olx if there is an online seller for it.

[jick.cejoco]

the cost of cleaning and re-gapping the spark plugs versus replacing them with new ones is not that much of a difference in cost of parts compared to the cost of labor (time). most newer cars have either platinum or iridium plugs because of this reason plus the reduced chance of stripping your spark plug holes. the plugs now are of the time change type.


btt

try reorienting your distributor by re-clocking it and rearrange the cylinder configuration on the distributor cap to see if it is the engine or the distributor(or cap) is the cause. if by reconfiguration or re-clocking of the distributor transfers the misfire to another cylinder, then it is your ignition that it the problem. for example: since you have a toyota four cylinder, your firing order is automatic 1-3-4-2. re-clocking it could be done by re-assigning cylinder 1 of the engine to supposedly cylinder four of the distributor cap, hence, cylinder 2 and cylinder 3 of the cap will switch position. then see if cylinder 2 which was good now turns misfiring. this engine is a dinosaur and should not be too difficult to figure out. simple old mechanics. think mr. watson

[Chinoi]

I suspect that one of valve seals on cylinder no.3 was already defective and need replacement. Leaking oil on gap of spark plug will be burned and accumulate carbon deposits causing short circuit ofSP gap. Prolonged short circuit on SP gap will result damaged to HTW and also no spark voltage.

[EssB]

Pretty common cause of misfiring on K engines: leaking intake manifold or exhaust manifold gasket... or baka lumuwag lang yung bolts ng intake/exhaust manifold near cyl no. 3.

[shelu]

to erase your doubts, bring the car to your suking shop. borrow distributor and see how it works. if it's ok, then buy one. i do suggest get an electronic dsitributor, less hassle. if you are into diy, there's a toturial on how convert your contact point dist with an igniter. i think i read it here in tsikot.. hope this helps.

[neil.corrigan12]

it is a lack of a firing plug usually, cheack the following
causes:

•Spark plugs
•Spark plug wires
•Ignition coil
•Fuel injector
•Wiring to fuel injector
•Timing Belt
•Vacuum leak or stuck open EGR
•Contaminated fuel or bad fuel pump
•Weak compression
•Blown head gasket

[Izzie]

Hello All!

Last January 1, I found the problem to the misfire of cylinder #3! The contact point gap is out of adjustment. I noticed that both screws that holds the contact point were not tight enough. (It seems my diy mech friend did not tighten it enough so the contact point came loose. )

Without my diy mech friend here (on a holiday) and no timing light or feeler gauge, I loosen the screws and made a guess by visually adjusting it. (I lightly crank the engine first to bring the rotor to "point" (almost) to #1 on the distributor cap before making the adjustment.)

Placed back the rotor and the distributor cap. Check HT wires and when I start the engine...it runs normal! Yes!!! I test drove it and I can say, its back to normal! Very responsive!

Thanks to everyone who helped me out here. Happy New Year guys!