What are the reasons an engine would miss fire

[CasKru]

I'm busy diagnosing the reason why my daily runner has an irritating miss.

To my knowledge there are basically 5 reasons a car would miss:
1) faulty plug leads / coil lead
2) faulty dizzy cap
3) faulty rotor / points
4) Ecu mapping
5) faulty plugs

I have replaced the plug leads thinking it could be the problem but this seems to have make it worse to some extend. The dizzy is also not what I am used to as it has a box shaped dizzy with the plug leads connecting in a straight line. So I'm guessing I have to do with something different than a rotor and points.

It's a Kia Picanto. I took this photo when I installed the new plug leads to fit them in the correct order again

2012-07-01-150.jpg (111.38 KiB) Viewed 2495 times

[pietpetoors]

And da plugs, start with da plugs they are the cheapest, I had a set which only did 2,000km on the Hilux and then one plug started giving problems

[CasKru]

And da plugs, start with da plugs they are the cheapest, I had a set which only did 2,000km on the Hilux and then one plug started giving problems

Die outjie moet oor 3000km nuwe timing belt kry en service. Het gedink ek sal dit sommer dan doen. Thanks

[Mr_B]

Another less common fault causing misfires is a faulty injector, which leads to air/fuel mix running lean on that particular cylinder. Others I can think if... intake manifold leaking, exhaust mani leaking, maybe a sticky valve... overheating coil pack, dirty or contaminated fuel...

[CasKru]

Thanks B.
Will check those.

[Bulletjie-3]

When the engine is hot or cold ?

[CasKru]

When the engine is hot or cold ?

Both but would say it's more pronounced when hot

[Mud Dog]

Do a compression test to diagnose or rule out internal mechanical faults like the valves and rings. Would also look at injectors and mapping if it's EFI. Plugs and leads are the most common causes next to cracked dizzy caps.

Good luck!

[CasKru]

Do a compression test to diagnose or rule out internal mechanical faults like the valves and rings. Would also look at injectors and mapping if it's EFI. Plugs and leads are the most common causes next to cracked dizzy caps.

Good luck!

Thanks... will do

[Bulletjie-3]

Check if the sparkplugs aren't cracked.

[CasKru]

Check if the sparkplugs aren't cracked.

Sal so maak dankie. Wil ook sommer 'n gap check

[Doom]

Het sy teleskoop nie dalk gestamp nie? Agter gekom dis die mees waarskynlike rede vir 'n miss fire?

[CasKru]

Het sy teleskoop nie dalk gestamp nie? Agter gekom dis die mees waarskynlike rede vir 'n miss fire?

[Vlak vark]

Ek sien hy het 2 coils en werk op wasted spark. 2 pistons kry gelyktydig vuur. Maak seker die pickups is skoon. Hulle sit gewoonlik op die cam, volg net die drade van die coil af. Kan dalk ook n sticky valve wees. Gaan ook jou vacuum pype na dat hulle nie geperish is nie, anders sal die vacuum advance nie reg wek nie.

[CasKru]

Ek sien hy het 2 coils en werk op wasted spark. 2 pistons kry gelyktydig vuur. Maak seker die pickups is skoon. Hulle sit gewoonlik op die cam, volg net die drade van die coil af. Kan dalk ook n sticky valve wees. Gaan ook jou vacuum pype na dat hulle nie geperish is nie, anders sal die vacuum advance nie reg wek nie.

Dankie

Het darem al uit gevind waar sit die cam sensor so weet darem waar om vir hom te gaan soek

[Hilux 1]

dalk daai swem deur die bad? bietjie water gekry waar hy nie moes nie?

[Mud Dog]

dalk daai swem deur die bad? bietjie water gekry waar hy nie moes nie?

Dis nie die Hilux nie ....

It's a Kia Picanto. I took this photo when I installed the new plug leads to fit them in the correct order again

[CasKru]

dalk daai swem deur die bad? bietjie water gekry waar hy nie moes nie?

Dis nie die Hilux nie ....

It's a Kia Picanto. I took this photo when I installed the new plug leads to fit them in the correct order again

Ja nee... die Hilux het nog nie 'n beat gemis in die 4 of wat jaar wat ek hom het nie (behalwe nou toe die dizzy bietjie water in gekry het)

[LouisZ]

Het jy reggekom met Hilux? Sal die Kia ook 'n Lamda of knock sensor he? Hulle se ook kyk na die Crank sensor, ook die coil pack toets

[CasKru]

Het jy reggekom met Hilux? Sal die Kia ook 'n Lamda of knock sensor he? Hulle se ook kyk na die Crank sensor, ook die coil pack toets

Al die goed is geskeduleer vir die naweek. Sal maar sien by hoeveel van dit kom ek uit

[CasKru]

Okay... net so vinnige feedback... weet julle sit al meer as 'n maand lank op die punte van julle stoele om te hoor wat gaan hier aan... hehe

Laas week toe slaan die kilos mos nou oor na die 90K toe. Koop toe al die diens parte en timing belt met sy tensioner.

Saterdag vervang ek toe die timing belt en tensioner, doen 'n full service (Al die filters, spark plugs en olie). Toe ek hom daar opstart toe klink hy somer weer beter. Ek gaan lees toe bietjie op KIA se forums en sien hulle reken die sparkplug gap is beter om hom tussen 0.030 en 0.032inch te stel. Gaan doen dit toe en nou loop hy al te mooi. Dankie vir almal se voorstelle en idees.

Nou wil ek sien of sy petrol verbruik verbeter van 18km/l af

[Cleaner]

Nou wil ek sien of sy petrol verbruik verbeter van 18km/l af

:alvarin: