Glow plug light re-illuminating briefly after starting

[Jimbob1979]

I have started noticing when I start my Bongo (2.5D 1996) the glow plug light illuminates again for about 2 seconds after the engine starts. I have replaced the plugs recently with NGK ones as one of the existing ones was faulty causing smoke and rough start which is now resolved. Also, I am not sure if it is related but when I turn on the ignition (before starting) there is a kind of humming sound for about 5-10 seconds which sounds like it coming from somewhere near the diesel pump. I was looking at your Fact Sheet on diagnostics with a volt meter but I could not quite understand the wiring. Can anyone explain what the lead is that goes from TEN with a label of MACCA on the other end should connect to and also if anyone has any idea what may be causing this issue. I have had a doog look through the forum and although a lot of people mention a glashing glow plug light relating to diagnostics i from what i can tell this would not be relevant on a pre 99 model.

Many thanks

Jim

[jaylee]

I'm going to stick my neck out & say the "humming sound" could be something earthing or going to ground where it shouldn't???

Is it more like a buzz?? Just an idea...!


Geoff!!!

[g8dhe]

That's the Earth/chassis symbol, I guess MACCA is earth in Japanese without checking!
This site may also be helpfull http://www.philmcfadden.co.uk/MazdaDiagnosticBox.htm

[Jimbob1979]

Thanks for the reply. I did think about an earth issue as i had replaced the old longer plugs with shorter ones and adapted the bus bar but nothing is touching and it does stop after a while. Also it does not correspond with when the glow plug light goes out but from what i understand this does not mean the plugs no longer have power to them anyway. Does the cold start vacume solenoid make a noise apart from when it initially engages?

[Jimbob1979]

Thanks Geoff, that site is really helpful.

[jaylee]

Does the cold start vacume solenoid make a noise apart from when it initially engages?

You could try testing to make sure either one of the two vacuum solenoids isn't duff by un-plugging the connector to the one on the right & see if the idle solenoid pulls back... Then with the right one plugged back in & the left one un-plugged check to see if that works the idle solenoid with the AC on.... Both sort of work together when cold starting (& from my knowledge) drop the idle in increments as the engine warms up...?

http://igmaynard.co.uk/bongo/forum/view ... e+solenoid

[Jimbob1979]

Thanks, i'll give this a go tonight. Any idea on the glow plug light re-illuminating briefly after starting?

[jaylee]

That one will need an answer form a more knowledgeable peep...

It the glow plug relay clicking while this happens..?

[Jimbob1979]

It's hard to tell as the engine is running at that point but i will see if i can find out with someone else listening

[g8dhe]

I did think about an earth issue as i had replaced the old longer plugs with shorter ones

No the jumper to the TEN connection is to EARTH this enables the diagnostics to flash the pulses on the FEN line so that the meter/lamp can be used to display the pulses.

[jaylee]

It's hard to tell as the engine is running at that point but i will see if i can find out with someone else listening

Holding the relay (forefinger & thumb) & feeling for the click helps too..!

[Northern Bongolow]

the cold start solenoids can buz when they start to stick, this is usually the white plugged one as its first in line and collects most of the moisture out of the vac line.

[Jimbob1979]

I just took the wire off the glow plug bus bar and turned the igninition and there was no buzzing. I have had a good look and i cannot see the bar is touching anywhere. Is there anything else that is activated when the plugs have power to them?

[the laird]

Had a faulty glow plug doing that with the light b4,even when new p,us fitted (may not b

[Jimbob1979]

I don not think any of the plugs are faulty as it is starting well. I changed them recently becuase one was broken and it was very rough