Spark plugs with resistors and without - What's the diff?

[webmiester]

Hi guys,

My lancer's speedometer and odometer has been malfunctioning for a long time. I called up a Mits dealer and one of their technicians told me that it could be due to the wrong spark plugs. A common problem was the replacement of spark plugs using spark plugs without resistors (without the "R").

I don't see the logic behind this. What are the spark plug resistors for? Can they really affect my speedometer/odometer? How do we determine if the sparkplugs we are using has resistors or not?

Thank you.

[danesjr]

Yep it could.
Resistorized sparks as the the name says, has additional resistance before the energy gets to the tip to generate the spark. I think it is usually 5KiloOhms. Why add a resistance? This is to reduce RFI or radio frequency interference that is bad for the electronics in the car(read ECU) that is why an R spark is recommended for EFI or in Mitsu ECI engines.
On NGK spark plugs, The name of spark will tell you if it is resistorized. BK5E is not resistor and BKR5E is resistor spark. Use only spark plugs recommended for your car to avoid damage.
so What's Your Lancer?hth

[Galactus]

Huh???

Any decent mechanic worth his salt can tell you that the spark plug has nothing to do with the speedometer/odometer malfunctioning. AFAIK, not only Mitsu engines require resistorized plugs, even Honda & Nissan engines have OEM "R" spec plugs. And those plugs are properly shielded from RF interference. That mechanic's diagnosis is highly doubtful.

Check the VSS (vehicle speed sensor). That's the common culprit for errant speedometers.

[webmiester]

If I pull out the spark plugs right off my engine, nakasulat ba duon yung model number? I talked to an NGK dealer and told me that both the resistorized and non-resistorized plugs look exactly the same. Although in one website, I saw a pic that showed that resistorized NGKs have an "R" printed directly under the NGK logo.

[webmiester]

Ang galing! I changed my spark plugs and hindi na nagloloko speedometer/odometer ko for 3 days straight!

BTW, how will I know if other brands such as Bosch,Champion,Splitfire or Denso's plugs are resistorized?

[rayban7g]

I've used Bosch, pero not familiar w/ its' code (FRXxxx) basta parang ganyan. Kung carb lancer mo (like '99-'00 GLX nameron pang nilabas), kahit di na resistorized yun, pero kung EFI recommended 'to. I think the SP code of NGK for lancer is BPR5E for EFI or BP5E (non-resistorized).

Or you can search on google for the cross-reference of each brand, there are tables given what are the counterparts of it.

[Galactus]

Ang galing! I changed my spark plugs and hindi na nagloloko speedometer/odometer ko for 3 days straight!

BTW, how will I know if other brands such as Bosch,Champion,Splitfire or Denso's plugs are resistorized?

Speedometer/Odometer ba talaga or TACHOMETER??

I had erratic idling before to the point na namamatayan ako ng makina. The plugs were new, but Migs of Speedyfix said na baka plugs ang problema. So he pulled out a used set of plugs, and voila! Nawala ang nginig, and ok na idling.

Parang imposibleng may kinalaman ang sparkplugs sa malfunctioning speedometer/odometer.