power loss on hills

Technical questions and answers about the Mazda Bongo

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berrega

Re: power loss on hills

Post by berrega » Thu Apr 01, 2010 3:43 pm

Right then.

the 20 amp fuses under the bonnet look fine.

I found the fusable link. on inspection it looks fine, no charing, melting etc.

[edit] Tested its strechyness. It seams fine and in good condition.

Presumably I still need to check its resistance ?
but on the face of it it looks intact.
Last edited by berrega on Thu Apr 01, 2010 4:40 pm, edited 1 time in total.
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g8dhe
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Re: power loss on hills

Post by g8dhe » Thu Apr 01, 2010 3:45 pm

Do you have a multi-meter ? To check voltages etc. ?
Geoff
2001 Aero V6, AFT, full side conversion.
berrega

Re: power loss on hills

Post by berrega » Thu Apr 01, 2010 3:54 pm

yeah, just bought one.
figured I might need it.
never used it before though ;-)
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g8dhe
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Re: power loss on hills

Post by g8dhe » Thu Apr 01, 2010 4:58 pm

Now is the time to start!
Select the 20 Volt range, put the meter leads in, Black to -ve or Common, Red to +ve or Volts.
Lift your engine cover so that you can get to the Glow Plug bus bar, connect the Black lead to the chassis - firmly, hopefully you have a clip, if its just a pointed probe then find a small clean hole to stick it in that is clearly part of the chassis!
Switch on the ignition and turn to the Glowplug ON position, using the Red probe/clip attach it to the Glowplug bus bar you should get a reading greater than 10 volts. If so then you can be certain the relay, and fusible link are OK.
Disconnect the meter.
It could still be the Glow plugs themselves, or other engine problems - I'll let others advise on those aspects!

If you don't get greater than 10 volts, then switch the ignition OFF. First check carefully that the Bus bar is not shorting out to the chassis anywhere - this is the most likely cause of the problem.
If not then close the engine cover, move to the bonnet. You need to now check the voltages at both the battery end and the relay end of the Fusible link - the Lush project diagram suggests it has connectors at each end but not sure how easy it is to get the probes to make contact, its best NOT to pierce the insulation with the probes. Check the voltages both with the ignition off (I would expect about 12+ volts if the battery is fully charged) at both ends, and again with the Glow Plugs ON, you expect to get slightly lower voltages, but if the end of the link furthest from the battery is more than a volt less than the battery end then the connections need cleaning. If it looks OK, then the relay is next in line for suspicion, but it can only really be checked by substitution, but its worth making sure the blades of the relay are clean and I think you have already changed the relay once ?
Geoff
2001 Aero V6, AFT, full side conversion.
berrega

Re: power loss on hills

Post by berrega » Thu Apr 01, 2010 5:51 pm

when the glowplug light is on and the black pointer is on the van body work and the red is on the glowplug bar I get a reading of 0.00 Volts. (if I start the engine that changes to -0.02V) will continue to read.

If I seperate the black plastic box of the fusable link and bridge the gap with the volmenter I get a reading of 0.00v ( 0.0v if the glow plug light is on)

if i unscrew the 'o' connecter and stradle the gap between it and the battery connecter/fuse housing I get 6-8 volts (0.5 v of the glowplug light is on)

I used the fusable link to join with a 1.5v battery and then tested it wih the volt meter and got 1.4volts.
so that shows the wire is still connected.

Does this make any sense?
I have a feeling i'm doing iit wrong.
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Re: power loss on hills

Post by munroman » Thu Apr 01, 2010 7:56 pm

What voltage are you getting from the main battery?

It should be around 12V, if you are finding 6-8v in the wiring that sounds too low.
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g8dhe
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Re: power loss on hills

Post by g8dhe » Thu Apr 01, 2010 8:30 pm

OK well your not getting any supply to the Bus bar as that read 0 Volts, but you measure the voltage the same way each time, from chassis to a specific point, you don't remove the fuse at all. So the readings you took stradling the fuse holder is not right. At least you know now that the problem is between the Battery and the Bus bar so ..... Did you double check that the Bus bar isn't touching the chassis anywhere, as that seems to be the most common problem reported ?

With your meter's Black probe always on the chassis, and the Ignition OFF, use your red probe to measure the voltage at the Batteries +ve terminal it will be about 12 volts, note it down.
Now move the Red probe to the point where the Fusible link connects to the battery without disconnecting the link, note the reading it should be much the same as previous.
Now move the Red probe to the other end of the fusible link, if you can, again don't remove the fusible link, it should again be the same.
Now turn on the ignition to power up the Glow plugs, measure the voltage again at the same place, I would expect the same or maybe a little lower voltage.
If its up around the +12 volts then the link is OK. If it falls to 0 volts then you have corrosion/break somewhere on that wire back up towards the battery.

That only leaves the wire from the fusible link to the relay and between the relay and the Bus bar, either the relay is being operated when you turn the Ignition on, or the relay is faulty.
Getting to the wire that turns the relay on is going to be a bit more of a problem, and I don't have the specific diagrams to be absolutely sure that they are the same as previous versions. But it does sound like the relay is operating as the voltage changes when the Glow Plug light comes on.
If your able to get to the underside of the Glow Plug relay then you can make measurements there but not sure that is possible ?
Geoff
2001 Aero V6, AFT, full side conversion.
berrega

Re: power loss on hills

Post by berrega » Thu Apr 01, 2010 9:48 pm

Think the batery was 12.48v or something similar.

to be honest I cant see how the buss bar can touch the shassy anywhere.
we are talking about the thin metal strip that runs across the 4 glow plugs?
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missfixit70
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Re: power loss on hills

Post by missfixit70 » Thu Apr 01, 2010 10:02 pm

Doesn't have to touch the chassis, touching anything other than the end contacts on the glow plugs will create a short.
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berrega

Re: power loss on hills

Post by berrega » Thu Apr 01, 2010 10:35 pm

ok

black probe on shassy, red probe on the'o' shaped contact where the fusable link attaches 12.65Volts

How can I messure the other end of the fusable link as it connects inside a black plastic box?
if I disconnect the plastic box and measure the other side of the plastic box of the fusable link it reads 12.65 volts,

I then turned the glow plug light on and connected the black probe to the shassy and the red probe to the place where the fusable link connects the battery. The voltage started to climb at around 11,12 volts the spike broke of the probe making the multimeter unusable because I am cursed...
berrega

Re: power loss on hills

Post by berrega » Fri Apr 02, 2010 8:59 am

ok ignore my previous posts.

I had been testing the bus bar after the pulse sent to it had turned off.

I've wired the -ve probe to a nail so I can carry on using the multimeter :-)

the battery reads 12.16 volts.

When turning the key so the glowplug light comes on a pulse of 11.14volts
goes to the glowplug bus which lasts for 14 seconds.
then the relay clicks and it changes to -0.00v.

So this means my eletrics are fine doesn't it?

which mean I now need to concentrate on fuel running back into the filter, the fuel filter holder becoming semi-permiable,
and a compression test?
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Re: power loss on hills

Post by rita » Fri Apr 02, 2010 10:19 am

berrega wrote:ok ignore my previous posts.

I had been testing the bus bar after the pulse sent to it had turned off.

I've wired the -ve probe to a nail so I can carry on using the multimeter :-)

the battery reads 12.16 volts.

When turning the key so the glowplug light comes on a pulse of 11.14volts
goes to the glowplug bus which lasts for 14 seconds.
then the relay clicks and it changes to -0.00v.

So this means my eletrics are fine doesn't it?




which mean I now need to concentrate on fuel running back into the filter, the fuel filter holder becoming semi-permiable,
and a compression test?
Hi berrega,
If you want to test for the run back problem with the fuel.After the vehicle has been idle for a long period,disconnect one end of a injector pipe,turn the engine over a few times,you should get an instant flow of pressurised fuel.Take the usual safety precations.Hope this helps you..
berrega

Re: power loss on hills

Post by berrega » Fri Apr 02, 2010 10:33 am

where is the best place to make the disconnection?

the banjo connector?
rita
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Re: power loss on hills

Post by rita » Fri Apr 02, 2010 10:48 am

berrega wrote:where is the best place to make the disconnection?

the banjo connector?
Hi berrega,

NO You do not touch the filter,you have 4No pipes running from the Injector pump to the injectors,disconnect one of these pipes from one end,either the pump or the injector end.
When you turn the engine you should get an instant flow of high pressure fuel.(Protect you eyes etc.)

If you are not confident you should get a garage to do it.

Take care..
berrega

Re: power loss on hills

Post by berrega » Wed Apr 07, 2010 1:55 pm

Took it to a garage.

Suddenly it starts fine for them :-(
God I hate this van.

Presumably it is the temperature that is effecting the starting.
Thats the only thing that makes any sense.
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