Delica Canada | Mitsubishi Van Club

I've been working on this issue for a couple months and wondering if the Delica experts could lend some advice.

The issue: starting the van from cold (5 C), the glow plug relay only goes on for 3 seconds. Van won't start.

My van: 1992 Delica L300 2.5L Turbo Diesel (4D56 engine)

- I've put a meter on the coolant sensor terminal and confirmed that the ECU is receiving a signal that indicates that the coolant is still around 5 C (3.6V).

- I've put the meter on the terminal for the glow plug relay and confirmed that it's giving the power to the relay for only three seconds and then going back to 0 V - while the temp sensor is still at 3.6V.

- I've replaced the sensor and I've replaced the ECU. No change.

Any ideas about what could cause this? Are there components outside of the ECU that could cause it to prematurely end the glow plug energizing?

Cheers!

Hey

In my experience the older the glow plugs get the less efficient they are.
You may need to replace the plugs themselves.

I had a similar issue in both the Mitsu Challenger I had as we ll as the L300 I currently have.
In case of the challenger replacing the glow plugs solved the starting issue immediately.

Cheers & good luck.

I just removed the plugs and found that one was missing a tip. I'm really a mechanical newbie, I'm now wondering if I missed seeing the broken tip when I removed the plugs from the old head and installed in the new one (still on my way out of a cylinder head replacement). That tip could have been what cracked the roof of my No.2 cylinder in the old head.

Ok, I'm just going to get all new glow plugs to go with my new temp sensor and repaired ECU. All preventative maintenance I suppose for when I finally get the beast back to normal. Don't want any more tips breaking off.

Right now I can start it with ether if I wanted to (got it alive and driving a couples times already) but I know that's not good for it. So I know it mostly works, just a matter of heat in the coldest (5 C average) time of the year. I think the van would start if it were July.

Did extensive testing tonight and I can't find anything wrong. I thought the only 3 seconds of glow relay was something wrong but I now believe it's the 'super quick' 9V blast to the 6V glow plugs that only lasts 3 seconds. After that initial quick blast it goes down to 5V until such time as 3 minutes elapses or the temp gets to 40C.

Here's hoping that it's the glow plugs.

So I've installed new glow plugs and now I can get it to start without any ether, just a half dozen cranks and some accelerator pumping. When it catches I need to keep the accelerator depressed slightly to keep the RPMs up at 1500 or so. If it dips lower it stalls.

Could injection timing be playing a part in this cold starting issue? Even though it sounds fine when it's running and I know that it will probably idle normally once it gets warm enough, I wonder if the timing could be off. I did install a whole new head and had to bar the engine over while doing it. While I'm sure the timing marks are lined up on the belt, I know there's a special adjustment with just the pump that can be done.

well, let us know how it goes.
I sure hope it's the glow plugs, as that is a quick and easy fix.

Good luck.

Because there's no fast idle circuit, you have to hold the pedal down or use the throttle control knob when cold. Have you checked your compression? You need really good compression in a diesel to start when it's cold. 5C isn't all that cold and my van lights right up at that temp. You're sure there's no voltage drop across the glow plug relays?