poor cold starting 90 hdi

[bigknickers]

My 53 plate 90s 73,000 mile estate has just had a new battery, the starter throws her over fast enough, but first thing on a cold morning it will take about 10 seconds to fire up. During the day no problem, overnight on a warmish morning (above 5deg) no problem. What can you recommend?

[bigknickers]

I've just remembered something, my old 406 110 would show the glowplug light every time I turned the ignition on. On this 90 I have never seen the glowplug symbol lit up, does this mean the glowplug relay isn't working? or has it's fuse blown?...........god knows where I might find that thing............can someone tell me where the little sucker is!

[steve_earwig]

Which, the fuse or the relay? The relay doesn't appear to have a fuse, it's controlled by the engine ecu and fed off the alternator (que?). The relay lives on a bracket under the throttle pot.

An HDi shouldn't really need much in the way of preheating, unless it gets really cold the glowplug light only appears for a fraction of a second. It does actually work longer than that, it's on for a few seconds after the engine starts (unless you rev it) so perhaps it would be worth seeing what it's actually doing by putting a multimeter on a glowplug and watching it while the "ignition" is turned on and the car started.

Btw is this Bosch or Siemens? It might make some difference later on... Does it blow white smoke when it takes a while to start?

[PeterN]

As Steve says the Hdi should start OK without the glow plugs unless you live in Siberia. All of the starting and running problems I have had on Hdi's have been down to the pressure regulator on the HP pump, or rather the filter on it. Its not to difficult to change if you have a 1/4" ratchet and the appropriate bits, either torx or allen, its held on by two screws and a connector, you need to take the fuel filter off first - at least on the C5 you do.

Peter

[bigknickers]

Thanks for your replies lads,I appreciate your help, but here's the thing, my old 51 plate 110 hdi always had the glowplug light on when the key was turned (along with all the other dash lights). The glowplug light on this new car has never come on, so straightaway there is a fault there.
I am going to put this question in the electrical section because although I want to fix this problem, I am now intruiged as to how the whole glowplug activation and disactivation happens.

[lozz]

The ecu takes readings from the Tempsensor'.-glowplugs.

find the glow plug relay..get someone to turn the ignition on and you shouid here it click,

on 'Moody..vauxhall's we used to unplug the tempsensor this wouid get the glowplug light to stay on..
not sure if it works on hdi...never tried it,

[hasler88]

Unplug the sensor underneath the vacuum pump the light should come on for 10 seconds think its green

[rwb]

Good idea for checking them

The glow plugs are used on the HDi even when the light doesn't come on. (The light only comes on when it's very cold to ask you to wait.) To this end, do you jump straight in and fire it up, or do you get in, turrn the ignition on, fasten your seatbelt and then start it?

[bigknickers]

The light is yellow, it ALWAYS came on on my 110 (all year round),I never waited for it to turn off, just turned key as soon as I could and the car always started easily all year round.

So, the ecu I presume measures the resistance across the glow plug, when the plug has heated and therefore the resistance has become....... higher? the ecu somehow cuts the supply to the relay which in turn switches off the main current going into the glow plugs.

What about the 'switch on glow plugs' wire that comes from the 'engine coolant sensor' is this sensor different from the temperature gauge sender unit?

I will try to have a listen for the click

Sadly I am a mechanical cretin, so I have no idea where to find the sensor or a vacuum pump you mention

[steve_earwig]

Unplug the sensor underneath the vacuum pump the light should come on for 10 seconds think its green

Interesting, does that work for both sorts of relays?

The light is yellow, it ALWAYS came on on my 110 (all year round),I never waited for it to turn off, just turned key as soon as I could and the car always started easily all year round.

If it does come on in the summer it must be so fast I can't see it.

Engine ecu coolant temperature sensor, nothing to do with the gauge. The ecu decides how long to run it for depending on the temperature. It will run it longer than the light but that's just the ecu telling you it's ok to start it now.

If you can't hear a click you'll need to test it (12 volt test lamp is ok)

[lozz]

If the glow plugs/circuit was fault it wouid throw a fault code wouidnt it?

0380 or simalar..







/

[lozz]

this http://engine-codes.com/p0380.html

[bigknickers]

where is the vacuum pump? so I can take the plug off the sensor beneath

[keppler]

I know it seems to be a given these days that in our climate hdi's dont really require glow plugs to start easily however a mechanic buddy of mine, who is quite proficient with peugeot's developed a similar starting problem last week on his 2.0 litre 407. He changed the glow plugs and the problem was sorted.

Op have you tried getting someone else to throw the key to accessories and then ignition while you check the glowplugs with a multimeter? That would at least tell you whether they are getting power when they should be. Have the glow plugs been changed recently or ever been changed? Another thing you could do is remove the glow plugs and check them manually by running a current through them from the battery. If they're in good condition they'll glow bright orange/red all the way to the tip if not, well they may light to the tip but take a long time or they may not light at all (if you have a new one to test it helps to see the difference).

It is also possible the bulb in the binnacle is blown, quite possible actually. This would not effect the function of the glowplugs themselves btw.