Does +1 step colder Spark Plug affects Cold Starts ????

[Dezaremos]

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My Corolla Lovelife 2e Carb Engine's spark plugs was NGK BP5ES with the previous owner. When I bought it, I replaced it with a Bosch Platinum Plus, then Denso W16 after it.

Everything was running and starting fine with those spark plugs. But when I replace it last month with a Denso W20EXR-U which is a one step colder spark plug, it stalls on cold starts. The engine start but after a few seconds, it dies, then I start it back again, sometimes I lightly step on the accelerator to warm the engine up. Once it warms up, it runs fine.

The reason I replaced the W16 which has a heatrange of 5 with the W20EXR-U which has a heatrange of 6 was I've read in the Denso Global site that my 1999 Corolla 2e OEM spark plugs should be W20EXR-U.

Need Help..

[vernie]

> Does +1 step colder Spark Plug affects Cold Starts ?

The answer is no. Cold start situation does not involved the heat range factor, the engine is still cold.
However, spark plug gap, spark plug electrical resistance (spark plug material) and electrical contacts do affect the signal producing the spark. In your case, these are the affected factors when you changed spark plugs.

[Dezaremos]

> Does +1 step colder Spark Plug affects Cold Starts ?

The answer is no. Cold start situation does not involved the heat range factor, the engine is still cold.
However, spark plug gap, spark plug electrical resistance (spark plug material) and electrical contacts do affect the signal producing the spark. In your case, these are the affected factors when you changed spark plugs.

I think all of those previous spark plugs including the present one has a .08 gap. The W20EXR-U though is a resistorized one, the non-resistor version has no "R" eg. W20EX-U .. Could it be the culprit ??

What is electrical contacts ?? Do you mean the High Tension Wire ??

[STEVEN]

noose bleed mn sad ta ani?haha

[Dezaremos]

noose bleed mn sad ta ani?haha

aw! mag bisaya diay ta dri sir ?? atay! hahhhhaaahah