KE55 IDLING ISSUE

[rebuilder86]

wings, nope those plugs are fine.

runon is a good and a bad sign at once.

u can actually eliminate runon, but its quite difficult and almost pointless because the cutoff solenoid takes care of it for you. its just if u have severe run on, it can be a result of running too rich. which is something to look into.

now i don't say that because the rich mixture is easier to burn and "run on", i say that because the rich mixture leaves carbon which covers parts of the piston head and creates a hot spot underneath it(carbon doesnt conduct heat so well), which spreads outwards untill a very hot spot is created on the outer region of the carbon buildup. this ignites fuel air mix that is compressed enough.

On most engines, you should experience "run on" only after the engine has warmed up. this is because on most engines fuel is rich when warming up which keeps things cool. once it leans out, temps increase quite a bit and hot spots begin under the carbon and spread out until they reach an area not covered by carbon, and then you have a "hotspot"

if the run on lasts more than 2 seconds,  you have very good compression, but that may be due to a substantial amount of carbon covering your piston and or cylinder head. during light power cruise, this can cause preignition, which is different to detonation  or "pinging" sometimes called "pinking" by tossers.

i have experienced this on my shit mitsubishi express van. It would run on until i kicked it in the guts with the clutch and some help from a handbrake and 5th gear. even accelerating to put out the fire would make it just gurgle and run faster. one time i decided id see how long it would go, it went for about a minute.

a fuel metering air bleed solenoid on the carburettor, was not working due to a wrong O2 reading because of a cracked exhaust manifold.

this made the solenoid stay completely closed blocking the air bleed which made it run rich. very rich. this affected the entire primary circuit. in effect this caused a very big carbon buildup.

after i hacked the solenoid to remain open, the constant lean running solved the issue.

You may find u have a rich condition or a poor combustion. now would be a good time to look into cleaning the valves and running some seafoam through the engine to remove the carbon. Some people just spray water from a spray bottle directly into the hot engine at 1200 rpm, but ive never seen proof of it working to remove carbon. the theory is that the carbon cracks off due to the instant temp change. I'm not sure that would be good for the valve seats so i don't condone it.

some things to note about my point on carbon hot spots.

don't confuse (doesnt conduct heat so well) with (doesnt radiate heat so well)

conduction is physical contact, radiaton is the radiation of heat away from an object.

as the carbon cannot conduct the heat, it has nothing to radiate, so the piston crown underneath it, gets fucking hot. this spreads outwards until it reaches a place not covered in carbon, and there u find a "hotspot".

 

 

Edited October 26, 2017 by rebuilder86

[rebuilder86]

in fact uve just inspired me to go check my plugs. i may even plug the solenoid to the battery and go for a blast n see if it has any runon.