White Smoke & Lumpiness On Startup - Glowplugs Fine . . .

[dandywarhol]

The glow plugs are either ON or OFF via the relay, there is no reduced power mode on the Bongo that I can see from the diagrams;

The ECU does sense that power has actually been applied to the plugs, but that's all as far as I am aware.

The coolant temp sensor also tells the ECU to keep the plugs on longer but the turbo pressure also overides that to ensure the plugs are off under engine load

[g8dhe]

No idea if they "modulate" the current, I use sparks rather than glowing
But I haven't heard people saying that the relay clicks in/out frequently, it would be a rather poor method to use
I thought it just came on for about 20-30 seconds, but I'm sure there is a diesel man out there that knows ?


edit: Ahh a diesel man has already replied!

[dandywarhol]

They come on for around 15 seconds if the engine isn't started - otherwise the battery would drain. The dash light is only an indication of when to start the engine. if the engine is started in under 15 seconds then the glowplugs can stay on for as long as 5 minutes depending on the coolant temp (and obviously the ambient air temp). If trickling along in slow moving traffic then the plugs stay on until the coolant temp sensor tells the ECU to knock the relay off. If your moving then turbo boost pressure will tell the ECU to knock off the relay immediately to avoid them being used under power. Its supposed to be an emissions feature in Japan.

The reason I know this is because I fitted an override switch with an led which, if left on, would show me when the plugs are glowing. The relay clicking you hear is controlled by the turbo boost until the coolant heats up sufficiently.