Diesel Starting problem

[MULLEY]

Didn't realise the multimeter was effectively a small power source, its all starting to make sense. I'll have a look at my multimeter tomorrow to make sure its got the suitable setting that you mention

Questions are over for the timebeing Cheers

[electrokid]

Don't bother to check each glowplug until you've checked that there's power getting to them.

To make sure power is getting to the glowplugs - set the voltmeter to the 20v range and clip the + to one of the tips of the glowplugs where it is daisy-chained. Clip the - lead of the voltmeter to chassis or to the -ve of the battery.

Perch the voltmeter up by the windscreen so you can read it while sitting in the driver's seat, and make sure that the voltmeter leads aren't in any danger of getting caught in belts or moving parts in case you try to start the car.

Jump in and turn the ignition on - the orange light should come on and the voltmeter should read around 12v. After a few seconds the orange light should go out but the voltmeter should continue to read around 12v for a while until you hear a relay click - if you can't hear the relay you'll notice that the dash lights will brighten up a bit when the start relay switches off because the glowplugs are a heavy load on the battery.

If you don't get 12v on the daisy-chain then the start module isn't working - this could be the module itself faulty or not being switched by the ignition switch or a fuse blown.

If there is 12v there for the right amount of time then you need to check the glowplugs. Carefully disconnect the daisy chain and set the voltmeter to the lowest ohms range - usually 200? - clip the -ve voltmeter lead or force it as hard as you can to the bottom end of one of the glowplugs and connect the +ve lead to the connection at the top where the daisy-chain was connected.

The voltmeter should read around 1?.

Measurements of this low a resistance is only just within the capability of the average multimeter because of the resistance of the leads themselves and the meter calibration. To try and get a more accurate reading connect the two meter leads together and read the meter - say you get a reading of 0.7? - that is your 'error'. If you then measure the resistance of one of the glowplugs as above and you get a reading of 1.2? - that is the resistance of the glowplug + the error. Subtract the error from the 'total' reading to get the actual resistance of the glowplug - in this case 1.2? minus 0.7? gives you 0.5? resistance for the glowplug itself - which is fine.

Repeat the process for each glowplug in turn - they should all be less than 1? though this doesn't necessarily mean they are working ! I've heard that they won't work well if they are covered in crud or if the element is shorting out and only getting hot at one end etc - but the resistance check is a good starting point if you suspect them.

If you need to look at the start module - it's mounted on the NS wing behind the battery and from memory it's blue.

due to time or temperature,

The glow plugs stay on for longer when it gets colder - controlled by the start module I think.

[sarahjaneking]

due to time or temperature,

The glow plugs stay on for longer when it gets colder - controlled by the start module I think.

thank you - I know on the bus it clicked when the block was hot but I know some older models were on a timer - should've known the BX would be in amongst the more technologically advanced

[docchevron]

AFAIK there's a temp transmitter in the blue box of heat. Thermister I guess?
Dunno, but yes, it's done on temp not time.

[sub777w]

What a surprise, the 1st cold snap of the year & it took about 6 goes before the beast fired up.

The glowplug light on the dash only occassionaly comes on, however i always wait for the relay click sound before starting the car. Normally no issues, except for this morning. The car was turning over, it just wouldnt fire up. Took a 2nd dose of re-heating for it to finally fire up & i used the throttle as well as it was coughing & i'm pretty sure would have failed to start.

I'm hoping someone may have some ideas on what the problem might be? Is it a duff glowplug or 2 possibly? & if it is, are the glowplugs on all the xud engines the same type?

Cheers

sounds like its as simply as glow plugs matt make sure you fit decend glow plugs ie borsch or lucas and fit all 4 even if only 1or2 are down.and yes there are different heat rates on xud engines like turbo to non turbo plugs but they look the same but turbo ones have slightly finer tips cheers

[mat_fenwick]

This may be of interest regarding the different glowplug types. I'm pretty sure you don't have ABS, but if you do the glowplug relay (yes it is blue!) is between the radiator and nearside headlamp.

[Gibbo2286]

And if you're satisfied that the glow plugs are ok and you still have a problem you need to look at fuel drainback, try pumping the primer, if you need to prime regularly it's likely to need new valves in the filter head. Gibbo.

[MULLEY]

Not very cold this morning, so the car started up fine with just one lot of glowplug tries. Hopefully sometime this weekend i'll have a go.

Another question, it comes with 2 leads, & there appears to be 3 holes that they could go into, which one should it be?

10A DC - 10A MAX

V ohmsymbol mA - 600V AC
600V DC
200mA Max

CATII COM - 500V MAX

& What is the blue dial thing with slots in it on the left hand side which has lettering NPN in uppercase with lettters around it & npn in lowercase with the same letters?

Really showing my ignorance chaps

[Way2go]

For normal measurements the black lead should go in the one Marked "COM" and the Red lead should go in the one marked " V ohmsymbol mA - 600V AC, 600V DC,200mA Max " and you should use the switch to select the appropriate measurement range. If you want to measure Current of 200 mA to 10 Amps then move the red wire to the "10A DC - 10A MAX " hole.

(I doubt whether you will need to use the NPN thingy as that sounds like a basic transistor checker)

[Way2go]

Oh, and remember when you are measuring voltages that you measure across (or in parallel with) the circuit under test whereas in Current (mA, A) mode you must measure in SERIES with the circuit or you won't get a proper reading and will likely damage the meter!

[scarecrow]

I made a voltmeter melt trying to test a battery. I think it's called a short circuit

[Way2go]

I made a voltmeter melt trying to test a battery. I think it's called a short circuit

I think it's called measuring a Voltage whilst switched to the mA, A, or Ohms range.

[Oscar]

There's a Haynes manual on vehicle electrical systems that I have found useful in the past, and I am pretty sure that I have asked about using a multimeter here too and someone posted a link.

[Gibbo2286]

http://www.multimeterwarehouse.com/usingamultimeter.htm

[Oscar]

http://www.bxclub.co.uk/forum/viewtopic ... multimeter

Here we are. Must read it again.