Glow plugs etc.

Technical questions and answers about the Mazda Bongo

Moderators: Doone, westonwarrior

User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Glow plugs etc.

Post by sotal » Fri Mar 24, 2017 6:06 pm

I've got rough starting at the moment in the cold weather. It sounds like it only starts on 3 cylinders (at most) and the other has to catch up. It gives a nice cloud of smoke out. A couple of seconds with a few extra revs and it clears, then runs perfectly.

I figure that it is probably the glow plugs. I have a mid kitchen so access is limited without removing the drivers chair. However I tilted it back and got it high enough for a quick look under. I found the glow plugs across the top of the side of the engine. However near here there are 4 plugs but the left hand two are not plugged in. What are these plugs for?

How much needs removing to access the 2 plugs towards the rear of the engine?
User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Re: Glow plugs etc.

Post by sotal » Fri Mar 24, 2017 6:13 pm

Image
User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Re: Glow plugs etc.

Post by sotal » Fri Mar 24, 2017 9:20 pm

From a little reading, I take it, that the plugs go to the cold start solenoid?

I plugged them back in and it has started much better tonight but I need to leave it until morning to really find out.

Only question remaining is why would someone have unplugged it?!
Bob
Supreme Being
Posts: 15255
Joined: Wed Oct 17, 2007 12:54 pm
Location: North Somerset

Re: Glow plugs etc.

Post by Bob » Fri Mar 24, 2017 10:09 pm

Glad you seem to be on the right track, but as for why people do things... :roll: :roll: :roll:
Bongolia
Supreme Being
Posts: 1524
Joined: Fri Apr 01, 2016 2:17 am
Location: Folkestone

Re: Glow plugs etc.

Post by Bongolia » Fri Mar 24, 2017 11:39 pm

sotal wrote:From a little reading, I take it, that the plugs go to the cold start solenoid?

I plugged them back in and it has started much better tonight but I need to leave it until morning to really find out.

Only question remaining is why would someone have unplugged it?!
Couldn't quite make out what it was from the image but as I understand it the cold start was a northern (very cold region) Bongo device that fed the warm raw exhaust back into the induction to aid combustion and warm up when first started, I don't know for how long or how it was switched out but unlikely to be of use in anything other than extreme cold conditions. So maybe it was deemed better to disconnect it from the system.
Having said that I would assume there were sensors in place to ensure it were not triggered if not at those extreme temperatures. Hope that gives you something to search on.
Its things like this that I find fascinating about Bongos. Clever little vans. :)
User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Re: Glow plugs etc.

Post by sotal » Sat Mar 25, 2017 2:02 am

I'm not 100% sure that is what they are. As far as I was aware it isn't a cold region bongo. It didn't have the other bits associated.

It has 4 of these black things. They each have an electrical connector and a vacuum pipe connected. You can see the black and the white connector on the right of the image. These were both connected but the two rear ones weren't connected electrically. The vacuum pipes were connected.

They sit in front of the two glow plugs at the rear of the engine.
User avatar
Northern Bongolow
Supreme Being
Posts: 7713
Joined: Mon Mar 15, 2010 11:33 pm
Location: AKA Vanessa

Re: Glow plugs etc.

Post by Northern Bongolow » Sat Mar 25, 2017 2:13 am

the 2 rear ones that are disconnected are for the egr so yours must be blanked off or not working. to get at the plugs just remove the 2 10 or12 mm bolts that mount the plate to the inlet manifold and disconnect the vac pipes carefully as they are very very brittle, then lower the solenoids out of the way a deep socket is required for the plugs, be careful as these can snap while removing.
top tip.
lubricate with anti seize when putting the new plugs in and torque both the plugs and the screw tops to the man torque settings. make sure the connecting insulated bar does not touch or rub anything when refitting or it may short out the plugs.

when removing the vac pipes, mark them so they go back together in the right place.
User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Re: Glow plugs etc.

Post by sotal » Sat Mar 25, 2017 2:30 am

Should I leave the rear 2 plugs disconnected then?

Are the front two the cold start ones then? I take it they are fitted to all bongos?

I'll try and take the drivers seat out and have a proper look.

Thanks
User avatar
Northern Bongolow
Supreme Being
Posts: 7713
Joined: Mon Mar 15, 2010 11:33 pm
Location: AKA Vanessa

Re: Glow plugs etc.

Post by Northern Bongolow » Sat Mar 25, 2017 3:39 am

it depends whether you want the egr to work or not, short answer is egr are not a good idea on most engines as all they do is put used exhaust gasses back into the inlet manifold to re burn it again to clean it up more, but this puts crap into the inlet manifold and engine and into your oil. it does lower the temps in your engine though as a cleaner better air supply gives a better burn in the engine but creates more heat, its your choice really. the egr valve has a position sensor on it, so a faulty one can give a fault light to the ecu, if its not giving grief or a fault light it maybe best left alone.

the 2 front ones are fitted to all that model diesel bongos, cannot remember if the later facelift are pipped up the same,

of the 2 front ones the one to the left operates when the coolant is below app 10 degc then turns off at 10 degc, the white plug operates from just above 10 deg c to about 50 deg c then turns off. the white one also lifts the throttle when the aircon is switched on if the aircon works.
rita
Supreme Being
Posts: 3284
Joined: Tue Sep 15, 2009 7:11 pm

Re: Glow plugs etc.

Post by rita » Sat Mar 25, 2017 9:32 am

Northern Bongolow wrote:it depends whether you want the egr to work or not, short answer is egr are not a good idea on most engines as all they do is put used exhaust gasses back into the inlet manifold to re burn it again to clean it up more, but this puts crap into the inlet manifold and engine and into your oil. it does lower the temps in your engine though as a cleaner better air supply gives a better burn in the engine but creates more heat, its your choice really. the egr valve has a position sensor on it, so a faulty one can give a fault light to the ecu, if its not giving grief or a fault light it maybe best left alone.

the 2 front ones are fitted to all that model diesel bongos, cannot remember if the later facelift are pipped up the same,

of the 2 front ones the one to the left operates when the coolant is below app 10 degc then turns off at 10 degc, the white plug operates from just above 10 deg c to about 50 deg c then turns off. the white one also lifts the throttle when the aircon is switched on if the aircon works.

Very sorry for being old fashioned, I think most people would prefer the CRAP to stay where it should be rather in peoples LUNGS.

Its an easy job to remove the CRAP from the manifold but a bit more difficult from your LUNGS.

Ok who disagrees .....

Good Luck.
User avatar
sotal
Supreme Being
Posts: 1098
Joined: Mon Jun 01, 2015 8:52 pm

Re: Glow plugs etc.

Post by sotal » Sat Mar 25, 2017 9:36 am

Thanks, I plugged them back in yesterday and didn't get a warning. Seemed to run the same but it was only a short journey.

Will try starting it this morning whilst cold.

It has working aircon, and the revs seem fine with that engaged. They don't drop too low etc.

It is just the actual starting that gives rough running and smoke. It is fine during warmer weather but bad in cooler weather. Personally I think it is worse this year than last. A few seconds of throttle seems to clear it.

It is a 1999 facelift aft.
Bongolia
Supreme Being
Posts: 1524
Joined: Fri Apr 01, 2016 2:17 am
Location: Folkestone

Re: Glow plugs etc.

Post by Bongolia » Sat Mar 25, 2017 9:38 am

Depends on the size of the particulate.

Yours
Fence sitting of London. :D :D
rita
Supreme Being
Posts: 3284
Joined: Tue Sep 15, 2009 7:11 pm

Re: Glow plugs etc.

Post by rita » Sat Mar 25, 2017 10:05 am

Bongolia wrote:Depends on the size of the particulate.

Yours
Fence sitting of London. :D :D



Yep, but who wants to find out?.Diesel fumes may contain over 10 times the amount of soot particles than in petrol exhaust fumes, and the mixture includes several carcinogenic substances, meaning they have the potential to cause cancer.

The point is , if you intend or have removed the EGR capabilities , think of "Other" People first. Our children's future is in Our hands.


Good Luck.
User avatar
mikeonb4c
Supreme Being
Posts: 22871
Joined: Sun Nov 05, 2006 10:49 pm
Location: Living with Mango Bongo in the North West but with a tendency to roam
Contact:

Re: Glow plugs etc.

Post by mikeonb4c » Sat Mar 25, 2017 10:49 am

I decided not to tinker with my egr. Bongo runs fine and given what we're now learning it sounds like the egr is best left as per design?
Bongolia
Supreme Being
Posts: 1524
Joined: Fri Apr 01, 2016 2:17 am
Location: Folkestone

Re: Glow plugs etc.

Post by Bongolia » Sat Mar 25, 2017 12:08 pm

Ahh but yeah but no but EGR on Diesels increases particulate output.
:(
Post Reply

Return to “Techie Stuff”