White smoke and misfire on start up ? i have the cure !!!!!

[teenmal]

I have (well our Bongo has) the tough to start, lumpy idle and white smoke on starting in the cold.

The smoke and lumpiness suggests to me that its the glow plugs. I've checked the electrics first and I'm getting 11.6V to them until the relay clicks. Is this ok or should the voltage be higher? After the relay clicks off I'm not able to register the voltage switching on and off as others suggested should happen. What makes the relay switch back on and off?

The lumpiness and smoke stops as soon as I pull away, but while idling remains for quite a while, even after some revving.

Does anyone have any suggestions before I try taking out the plugs themselves? I'll have to invest in some new sockets for the job so want to check all I can before starting it. It doesn't look too hard, but quite awkward.

Hi,
After starting and running the vehicle from Cold the heaters should stay on for several Minutes until the engine gets to a reasonable running temperature(and depending on RPM).If this is not happening you have a fault.If you are just checking the voltage on the rail without the engine running it will show the voltage at aprox 11.6 volts for about 10/20 seconds.

HONEST..........

If you dont believe ME ask Dandy..


Cheers..

[tallbongo]

Ah good point. I only measured it without starting the engine as I wanted it to remain cold. Doh!

[tallbongo]

This morning was a cold one (ice inside the windscreen again) and signalled the return of the white smoke and misfiring. It started with no problems at all. It's a lot better than it was before I changed the glow plugs and cleared in a couple of minutes, but is still undesirable.

My first checks will be to ensure the glow plugs do come on again after the engine is started.

Is there anything else I could look at?

Cheers.

[wonkanoby]

the revs at idle should be higher at start up as well when its cold

you should see a servo type think push on the throttle cable were it connects to the arm

it also does this if a/c is turned on

[BongoDon]

I used to have quite bad problems with lumpiness on start up, and tickover dying at junctions during the cold weather.
But somewhere on here, I read about listening for the relay click, about 10 seconds after the glow plug light goes off.
Since I've done that, I've had hardly any problems.

I can see that some people here think that this shouldn't fix the problem, but it appears to have worked for me. And I agree that if you do it immediately after the click, it starts and runs perfectly. Leaving it a few seconds after the click, and it's not quite as good.

Anyway, Bea is in for her MOT today, so fingers crossed!

[tallbongo]

Good luck with the MOT.

I've tried all sorts of starting procedures, with no joy.

This morning it was a lovely start, so since the glowplug change it's only sub zero conditons that cause lumpiness.

Revs look ok, but will check out the servo type thingy and post startup relay switching at the weekend.