4D56 delica - glow plug problem

[jon]

hi all...

just managed to get my hands on a beautiful 89 mitsubishi delica 4x4 van - 4D56 turbo diesel model. i'm planning on getting a bio setup running for her, but first need to sort out a wee (i hope...) problem and was hoping someone could give me a few pointers.

i'm guessing it's the glow plugs, but am not so sure being a bit new to diesels. it starts perfectly when the engine is warm and runs very well, plenty of power. the problem is starting from cold. even after leaving the ignition on for a whole minute before cranking, it generally takes about three longish attempts to get it started. and while it's cranking over, it blows smoke, finishing with a giant black cloud when it finally kicks in. after that it runs a bit shakily for a while, but clears up as if nothing had happened after running for two minutes.

when i turn on the ignition, i can't hear a loud click which suggests to me it's perhaps a faulty glow plug relay. i used to have a 4D55 pajero and could clearly hear the relay click when i turned on the ignition...

anyone got any ideas? if it is the relay, could anyone suggest where i can find it, and how to test it? otherwise if it's the glows, is there a relatively idiot-proof way of taking them out and inspecting/replacing them or should i be getting a mechanic to do it...? or is it perhaps another problem that i haven't thought of....?

thanks!

jon.

[Tony From West Oz]

Re: 4D56 delica - glow plug problem

It does sound like GP failure.
To check, get a multimeter and measure the voltage on the glow plugs when someone turns on the Ignition switch.

If you have 12V it indicates the GP relay is OK, but some GPs may be blown.
If you have 10-11V it indicates you have several GPs working, starting should not be a big problem.
If you have less than 10V but more than 1V you have a wiring fault (high resistance connection or GP relay contacts burnt)
If you have less than 1V you have a problem with the GP relay or the fusible link supplying the GP current.


Removal of the GPs:

Remove wires (or conductor strip) from all GPs and put aside.
Use a multimeter and measure the resistance from the connector terminal to the head. Compare this with the short-circuit multimeter leads. the short circuit should be 0 ohms, the GP should be 0.5 - 1 ohm.
Using a jumper lead, connect +12v to each GP in turn. there should be a healthy spark when connecting and disconnecting, but should not be like welding (this indicates a short circuit GP)
For those which do not measure between 0.5 and 1 ohm (compare with a new GP for the vehicle):
Using the correct spanner, undo the GPs one at a time and remove from the head. NOTE: they may be difficult to remove, but be patient or you could break one off in the head (may need head removal to retrieve the broken bit of the GP)
Install new GPs (best to do a full set and keep any good old ones as spares, should a new one fail)
Re-tighten the GPs and reconnect the electrical connections.

Verify the voltages as above are now correct.
Start the vehicle and enjoy the experience.


The above are just guides and the problem may be elsewhere.
Have Fun
Tony

[Slippery]

Re: 4D56 delica - glow plug problem

You can use the idiots guide to see if the glow plugs are working by (carefully) removing them one by one. Reattach the lead and turn on the ignition/plug circuit. If it gets hot - it works.

[joe]

Re: 4D56 delica - glow plug problem

I have the electronic manual for that engine. (4D55/56)PM me if you want a copy.

[Captain_caveman]

Re: 4D56 delica - glow plug problem

Gday
Just make sure your glow plugs are 12 volt before applying power to them individually, some cars use 6 volt plugs
thanks caveman

[jon]

Re: 4D56 delica - glow plug problem

hi all... thanks heaps for all the advice. i checked out the glows - they looked in pretty good nick to me, so i ended up taking the van to an auto sparky to get the circuit checked out.
turns out the problem was with the timer that turns the glow plug circuit on/off. being an old import it's a bit of a task to find a replacement, so i just installed a manual push-button switch to activate the glows - no timers, no thermostats. works fine now - you just need to hold the button in for a few seconds before cold starting. and now i can also be sure the glows aren't staying on too long after the engine starts...
jon.

[antigraviddy]

Re: 4D56 delica - glow plug problem

I have this problem with my Delica Starwagon. Is that electronic copy of the engine still available? What section would it be under in the manual? Thanks in advance.

[Johnnojack]

Re: 4D56 delica - glow plug problem

hi all... thanks heaps for all the advice. i checked out the glows - they looked in pretty good nick to me, so i ended up taking the van to an auto sparky to get the circuit checked out.
turns out the problem was with the timer that turns the glow plug circuit on/off. being an old import it's a bit of a task to find a replacement, so i just installed a manual push-button switch to activate the glows - no timers, no thermostats. works fine now - you just need to hold the button in for a few seconds before cold starting. and now i can also be sure the glows aren't staying on too long after the engine starts...
jon.

I like that solution, simple but effective.

[summerscheifer]

Re: 4D56 delica - glow plug problem

It does sound like GP failure.
To check, get a multimeter and measure the voltage on the glow plug when someone turns on the Ignition switch.

If you have 12V it indicates the GP relay is OK, but some GPs may be blown.
If you have 10-11V it indicates you have several GPs working, starting should not be a big problem.
If you have less than 10V but more than 1V you have a wiring fault (high resistance connection or GP relay contacts burnt)
If you have less than 1V you have a problem with the GP relay or the fusible link supplying the GP current.


Removal of the GPs:

Remove wires (or conductor strip) from all GPs and put aside.
Use a multimeter and measure the resistance from the connector terminal to the head. Compare this with the short-circuit multimeter leads. the short circuit should be 0 ohms, the GP should be 0.5 - 1 ohm.
Using a jumper lead, connect +12v to each GP in turn. there should be a healthy spark when connecting and disconnecting, but should not be like welding (this indicates a short circuit GP)
For those which do not measure between 0.5 and 1 ohm (compare with a new GP for the vehicle):
Using the correct spanner, undo the GPs one at a time and remove from the head. NOTE: they may be difficult to remove, but be patient or you could break one off in the head (may need head removal to retrieve the broken bit of the GP)
Install new GPs (best to do a full set and keep any good old ones as spares, should a new one fail)
Re-tighten the GPs and reconnect the electrical connections.

Verify the voltages as above are now correct.
Start the vehicle and enjoy the experience.


The above are just guides and the problem may be elsewhere.
Have Fun
Tony

thanks for the post tony it really helps a lot. i measure the voltage on the glow plug.have a problem because my voltage is less than 10V but more than 1V. and i just discovered that its wiring fault. really helps.

[gustycrosswinds]

Re: 4D56 delica - glow plug problem

hi all... thanks heaps for all the advice. i checked out the glows - they looked in pretty good nick to me, so i ended up taking the van to an auto sparky to get the circuit checked out.
turns out the problem was with the timer that turns the glow plug circuit on/off. being an old import it's a bit of a task to find a replacement, so i just installed a manual push-button switch to activate the glows - no timers, no thermostats. works fine now - you just need to hold the button in for a few seconds before cold starting. and now i can also be sure the glows aren't staying on too long after the engine starts...
jon.

do you happen to have a write up of the schematics of wiring them to a push button. i need to do this with my mighty max and it seems like a complicated system so i would like to know how you did it so i do not create electrical issues. thank you!