Bus not starting after short spell running !

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Merlot man
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Bus not starting after short spell running !

Post by Merlot man » Sun Mar 01, 2020 8:07 pm

Hello all
I've a 95 4wd diesel bongo which starts really well , first turn if the key , until this afternoon .
I did a small job on her , (remove the rear struts to get them regassed ) , and started her to move closer to the garage door and then turned her off to do the job , the start/ stop took no more then 15-20 seconds , when I went back to start up again she just turned over no kick like she was out of fuel , went and got a gallon of fuel put it in tried again and still nothing I kept at her until she eventually fired up and she ran really nice as is her norm .
Fuel gauge said half full but I drove back to fill up and filling her to the neck was only €50 , about half the tank as the gauge said !
She started on the first turn and drove home with out incident ......
Anyone got any ideas as to why this happened as I don't want to repeat it when in a hurry :shock:
This is her second time doing this the last was about a month ago with the same results
Any / all advice greatly appreciated
Brian
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Re: Bus not starting after short spell running !

Post by g8dhe » Sun Mar 01, 2020 8:16 pm

Was the van parked at an angle at any point ? Wondering if the fuel had run back at all ?
Geoff
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Re: Bus not starting after short spell running !

Post by Merlot man » Sun Mar 01, 2020 9:18 pm

Hello Geoff
The bus has been parked behind the house which is level more or less and as far is I can tell it was just under half full of fuel .

Brian
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Re: Bus not starting after short spell running !

Post by Merlot man » Mon Mar 02, 2020 3:20 pm

Hello plonkatronix and thanks for your post
I think I can hear the heater plug relay coming on but ill check that with a multimeter .
She had ,I believe , air leaking in at the fuel filter bleed screw before but a sealed that with a large rubber washer which cured my last poor starting issue , sense then she has always started on the first crack really easily .
where is the fuel cut -off solenoid located and how do I check that ?
If the fuel is draining back , how would I know/check ?
She has no immobiliser fitted
Thanks again
Brian
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Re: Bus not starting after short spell running !

Post by Merlot man » Tue Mar 03, 2020 9:01 pm

Hello plonkatronix
Well I've started the bus now a few times going to and from work etc since the incident with no problem at all :shock:
She Is back to her previous easy starting state :oops:
I'm still going to have to look into this to see if there's anything wrong , this weekend I hope .
The confusing thing is that there are very few diesel bongo that start better .......usually :lol:
Any other thoughts please feel free .....
Brian
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Re: Bus not starting after short spell running !

Post by Merlot man » Tue Mar 10, 2020 10:04 pm

Hello all
Well today the same as before ........she turned over and over and no start !
Now when the glow plugs were on I could hear the relay " clicking "rapidly instead of clicking on then off .
This evening the same but she did start after a few more cranks , still could hear the click,click,click click and when I put my finger on the relay I could feel it clicking .
So does this mean that the glow plug relay is goosed ? ......and I may have got to the end of my starting issues !
All help appreciated
Brian
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Re: Bus not starting after short spell running !

Post by g8dhe » Tue Mar 10, 2020 11:44 pm

Its not normal for a relay to "oscillate" in the way you describe, unless the supply voltage to the relay coil is dropping when the contacts make and the extra current drawn by the glowplugs is causing the coil voltage to fall, however if it was a battery problem the starter motor would be less than happy, so I would suggest checking the earth to the relay and also if you have the means the voltage to the coil to see if there is something odd going on.
Geoff
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Re: Bus not starting after short spell running !

Post by Merlot man » Wed Mar 11, 2020 9:38 am

Thanks for the quick response gents .
The battery is only a few months old and as you say she cranks very well .
Can I ask where this coil is and how I check it , also the relay is mounted on a steel bracket to the body .is this the earth and if not where do you mean ?
Sorry for all the simple questions but I'm very new to auto electrics :lol:
I'll will have a good look at all the connections tonight and see if I can find anything !
thanks again for both your help , its really very much appreciated =D>
Brian
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Re: Bus not starting after short spell running !

Post by g8dhe » Wed Mar 11, 2020 10:13 am

The coil referred to is part of the relay inside the case, a relay is two basic parts an electromagnet - the coil - which attracts the contacts (one of them) by the magnetic lines of force, these two contacts then make contact and allow the current to flow in the second circuit.
The earth is a black wire on one of the relay connectors that runs inside the loom to one of the earthing points, in this case inside the engine housing under the passenger side I think.
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Re: Bus not starting after short spell running !

Post by Bob » Wed Mar 11, 2020 10:32 am

Someone else suggested these on a thread recently, power probe, a great bit of kit:

https://www.ebay.co.uk/itm/223724536442 ... noapp=true
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Re: Bus not starting after short spell running !

Post by Merlot man » Wed Mar 11, 2020 5:49 pm

Thanks for those posts gents , that sealed tool looks interesting Bob !
If it is the coil thats the problem does that mean , for the likes of me , that I'm replacing the relay ? I assume it is !
I'll try and check the earth this evening , under the passenger seat you say ?
Thanks again I'll see how I get on
Brian
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Re: Bus not starting after short spell running !

Post by g8dhe » Wed Mar 11, 2020 6:54 pm

No its unlikely to be the coil itself, its the power being supplied to the coil that is likely to be the problem, this could be a poor earth connection. However its not really possible to say beyond that with out measuring voltages etc with a meter. Get to the relay, check its connector as starters, after that it really needs a meter to start measuring voltages to be certain, given the cost of the glowplug relay its not the sort of thing you want to replace without knowing that it is at fault.
Geoff
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Re: Bus not starting after short spell running !

Post by Merlot man » Wed Mar 11, 2020 9:58 pm

Hello again Geoff .
I've been out to the bus this evening and checked and cleaned all three connections on the relay using fine sand paper , I've also scratched the insides of the wire connectirs and to be honest everything looked good !
The only thing I found under the passenger seat that looked like an earth was bolted to the chassis leg and connected to the loom so I cleaned and sanded around there .
I connected everything back up and she started right up although I did hear / feel the relay clicking a few times .
I tried it a few times and the clicking seemed to reduce to one click , she started up then about another ten times with out any hesitation .....but im still not 100% sure .
I think I found the earth cable on the relay , it's black with a blue line ?
If I disconnected it from the loom and temporarily connected a new earth from the body with a crocodile clip to the relay would that help in eliminating / proving the earth as a problem ?
Also , the other heavy wire going onto the relay , I assume, is the live feed ( both have brown plastic connectors ) if I stick the legs of the multimeter in to each should I get a 12v circuit ? There is also a white connector with two wires but they are much smaller gauge wires .
As you can see I don't know too much about this type of thing but find it very interesting :shock: :D
To be fair I don't mind buying a new relay as I'm sure Ian with be fair to me as always [-o< It that cures it But I really want to get to the bottom of this once and for all
Thanks again Geoff and sorry for all the questions :mrgreen:
Brian
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Re: Bus not starting after short spell running !

Post by g8dhe » Wed Mar 11, 2020 10:53 pm

There are 4 connections to the relay;
Coil power = Violet
Coil Earth = Black
Contact to fusible link = Blue/Red
Contact to glowplugs = Black/Blue

DO NOT go round randomly connecting extra earths! You will only cause problems!

is the relevant page and also the next page for physical locations - you will need a Browser and Flash installed and enabled for the site (Chrome make life difficult).
Geoff
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Re: Bus not starting after short spell running !

Post by Merlot man » Tue Mar 17, 2020 5:21 pm

Hello again gents
Sorry for not getting back sooner but with all this corona virus we have bigger things on our minds , we are on more or less lock down here :shock:
Seeing as we are confined to our house/garage I thought I'd have another look at this relay ! :?
I took it out and had a good look at the connections going into the relay as per plonkontronix's advice and found that the connector coming from the fuseible link (blue /red wire ) looked corroded ,green , as it entered the brown connector , the rest of the connectors looked clean .
what does this mean ? Ive cleaned the fuseible link and it looks ok but I'm no expert :lol: :lol: :lol:
Can I simply cut off the brown connector and fit a new one ?
on the relay the male connector is around 8.6 - 9 mm wide , can I get a female spade connector that wide ?
As always thanks in advance .........and stay safe everyone
Brian
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