Hi all I have a L200 4d56 turbo diesel with cold starting problems.

When its cold I turn on the key, the battery volts on the gauge go down to 9V and the glow light comes on and there is a click behind the left front guard.

After 9 secs the glow light goes out, but the battery is still at 9V.
After 16 seconds the relay behind the guard clicks off and then the battery volts return to normal.
This is when I hit the key to start.
It does start but runs like a big hairy dog until I rev it and clear it and get it running on all 4 cylinders. Clouds of white smoke plough out the exhaust.

I have done some research and removed and checked the resistance and condition of the glow plugs they are all ok.
I have also cleaned them and made sure all electrical connections on glow rail are good.
I check the voltage to the rail which is battery 11.97v.
Also when the glow light goes out the volts to the rail stay on untill the relay behind the guard clicks off. This I have heard is normal.

My problem now is that after the 16sec relay clicks off the engine still starts like a hairy dog.

Next check, remove glow plugs again and indivually power them up and see if they glow.
They do, so i assume its not a glow plug.
Trouble is if I power them for the 16secs that the glow plug timer gives them, they arent really glowing, but if i give them an extra 5-6 secs I can get them glowing real well.

Questions:
1. Can i adjust the glow timimg so that they stay on longer?
2. If i do this am i going to create more problems and wear out the plugs?
3. Exactly how hot are these plugs surposed to get, a slight orange tinge or glowing bright like a real hot ember?
4. From what ive said and my checks on the plugs does it sound like they are worn out and are just taking too long to glow? should i just buy 4 more new ones.

:puzzled:

Any help would be much appreciated.

Hot starts are fine.

Regards
Matt :puzzled: :puzzled: :puzzled:

white smoke is usually an indication of coolant in the combustion chamber.has the vehicle ever been too hot.you may have a cracked head or leaking head gasket.a quick check of the radiator level should give you a rough idea.if yours is new enough to have an egr cooler then remove one of the exhaust pipes on the top and see if any poisture is present.it should look all black and sooty if things are fine.barring no sucess you can have the vehicle pressure tested at your local dealer.also check the incoming voltage at your glow plug relay-it should be nearly the same as battery voltage.the last thing (or first-up to you) is to remove the n/s front kick panel(if r/h/d) and look for a small black relay with 4 wires in it.it is single screw mounted and if positioned incorrectly can corrode causing many glow plug issues.they should only cost about £5 from your dealer if needed.best of luck

Thanks for your help...
its not the coolant.

What is the N/S kickpanel. I like the sound of checking the relay....
Mine is RHDrive.

Matt

Matt,
I have the same L200, the relay timing is 30 seconds, and I think this timing is the cause the glow plugs get burned once a year (using always the original ones).
Do you have the same problem? I think no because your relat cut timing is 16 seconds. I would to know what´s the reason the same engine has this two different timings.
Best regards!!
Guille

Glow plug timing is controlled by the resistance of a two-prong sensor which is located in the front of the engine, right in the thermostat box.
If that resistance increases, so does the timing.This can be tested by unplugging the sensor, thus telling the system it has an infinite high resistance, and checking that the dash indicator will take longer to change from red to green.But, even after the indicator changes, the glow plugs will remain activated, while you crank the engine, to reduce the amount of unburned fuel white smoke.
The glow plug are deactivated by means of the alternator light, which indicates that the engine is running. I learned this the hard way a time when the alternator stopped working and I noticed the glow plug indicator remained on after engine was running, and that burned all 4 of them!.
White smoke and rough idel after a cold start might also be an indicator of an injector not holding pressure and leaking overnight, or partially clogged.
Best shot is to remove injectors and have them tested at any reputed diesel shop.
Once you have them there, it's a good chance to decide uf you want them calibrated "tight", for better fuel economy, or "loose" for better pickup from dead starts. I have mine set tight, and get over 30Mpg on city driving with A/C on most of the times, and there is no black smoke on the tailpipe like other Mitsus I have seen.
Hope this helps!!

Hi,

Glow issues on th 4d56 are fairly common, but in saying that the 4d56 is known to run like a hairy dog when cold even when the glow system is working perfectly :-)

Mitsi use several different types of glow systems on the 4d56 depending on spec and region, so we really need to establish what type you have. They have different start procedures so it's worth while establishing which type you have.

Does your l200 have 2 glow relays or one? If it has one how many wires go to it?
Does it have a glow light on the dash? If it does tell me how it behaves when you turn the ignition on.

I've got wiring diagrams for most of them so once we work out which one it is we can start testing it to see if it is working ok.

Another reason is that 2 of the glow systems are designed to work without you waiting for the glow plugs to warm up. You just start and go, it could be that the 2nd relay click is the glow system turning off :-)

Cheers
Anthony

Many thanks for you answers!. I´ll be so gratefull y someone could send me the wiring diagram of the 4d56 glow plug preheating system (with the relays, the glow plugs, and the control unit).
best regards!!
Guille

Can anyubody sent me the circuit diagram of the 4d56 glow plug preheating system.Icluding relays control unit and glow plugs.

I need diagram for glow plug circuit can you e-mail please ,would much appreciate

sorry to butt in.. but i have the same issue.. but slightly different (91 l200 strada). glow light comes on but instead of clicking once it clicks twice. i then wait about 20 seconds turn engine over twice, then it clicks again so i can start. if i don't do it this way, timer just won't click off and i can't start it. any ideas if this is faulty glow plugs or am i looking at a relay??? (glow light on dash doesn't change colour).

also chugs out a whole lot of black smoke on first start up. goes perfect the rest of the day... (cept for smoking which we're currently trying to trace)

Black smoke usually it's and indicator of excess of unburned fuel, which in turn might be and indicator of at least 1 faulty glow plug.
Sometimes, instead of burn and remain as an open circuit, a glow plugs might develop a "bulge"on the tip which creates a short directly to ground, which may cause the unusual "clicking"of the relays.
Best shot is to remove the piece that conects the plugs togheter and test the plugs one by one, by slightly touching them with a thick (10gauge) automotive wire connected to the positive of the battery.Then pay attention to the intensity of the spark it creates, a "normal" spark indicates a good plug, no spark means a dead plug, and a huge spark means a shorted plug, which, in most of the times also causes the wire to try to stay "stuck" to the threaded tip of the plug.
If you determine that one of plugs has gone south, exercise extreme caution in the removal, since sometimes, if the have the "bulge" I mentioned earlier, they might broke, leaving a portion of the tip stuck in the pre-chamber( the hole is really tight, there is no much room for anything but the tip itself)which can be only removed by taking the head out(yes! costly and complicated!!) and most of the times, once the head is removed ans sitting on the workbench, it simply requires a couple of gently taps with a appropiate sized nail and a hammer.In really bad cases, the glow plug might even broke flush with the hole in the head, at the beggining of the thread, when you are trying to remove it, which is much more dificcult to fix.
Hope this helps! Luck in your troubleshooting!

huge help! Thanks so much :)