Fouled spark plugs

[ganda1f]

A friend of mine has a '94 Corolla with 4AFE (manual tranmission) and the plugs get a lot of carbon build-up after some 20000 km. According to the manual the plugs should last about 40000 km. The plugs are standard copper NipponDenso K20R. And they get sort of fouled for real. The car starts and stalls after 1-2 seconds. Then it won't start, cranks fine and ALMOST starts. So I removed the plugs and they were pretty much soaked with gasoline. Got new ones, problem gone.

Anyway, I have a theory that his driving habbits cause the plugs to fail prematurely. He frequently uses way to high gear. For example, going through intersections in 4th with speed below 30 km/h or something like this. RPM drops to about 600, the engine pretty much stalls. I keep telling him to stop doing that, but he fails to do so, which means that I can't really test if this is the problem. What do you guys think?

[Flashmn]

When plugs get flooded they cant fire, so drying them out would in most cases revive them. Also, I dont think the plugs are the issue here, its your fueling.

[ganda1f]

I did dry them out and indeed, the car started. Then I got the new ones and installed them. What I suspect, is that they got flooded in the first place, because they did not fire due to carbon build-up. So I wonder if this carbon build-up can occur as a consequence of the described driving habits. Or maybe you already answered that when you refered to fueling?

[Flashmn]

Well his driving habits certainly arent that great if he drives like that.

[ghost_ryder35]

his driving habits can cause them to get carbon build up. convince him to change driving habit, or try changing plugs to colder ones? or is it hotter ones? damn

[ganda1f]

Allright, thanks for the info. Maybe this time he will shape up

[Flashmn]

hotter ones foul less than colder ones, but hotter ones also can overheat faster causing detonation.