Short cycle on glow plug circuit

[jaggedfish]

Hi all... did a quick search this morning for glow plug circuit/ECM problems but didn't find what I needed sooo...

Hard start this morning... turned key, first click then very short time to second click... lots of black smoke and no start. Tried a few times with same result. Did eventually start with extended cranking but don't want to do that too many times. I have seen a lot of troubles with leaking capacitors and totally failed ECM but no mention of short cycle (thus cold glow plugs). Would this be a temp sensor issue or ECM issue? Any feedback would be appreciated... drowning in black smoke

[Rising Sun Auto Import]

Control unit problem most of the time.
Check this out.
http://www.delica.ca/forum/replacement- ... tml#p56391

[Green1]

sounds to me like a temperature sensor issue, the circuit thinks the engine is already warm so it doesn't bother running the plugs very long....

[TardisDeli]

Hi Jagged Fish,
I had very similar problem, turned out was just an extremely dirty air filter, altho it looked still good to me.

Yup, truly, although I had opened the air filter container and saw barely any dust, and vacuumed the air filter, and done lots of other testing. Having worst fear scenario in mind, I took it to Butch at CVI, he showed me my air filter which I thought still looked fine but Butch said was black with gunk (couldnt see thru it). So, only replaced air filter and did oil change, all is happy now so it was true.

Cheers, Christine.

[Pacific JDM Parts]

As Green 1 put it sound like the temp sensor has failed and not a control unit problem.You could also have failed glow plugs as the system need the correct resistances to operate.When the control unit fails it will not operate the relays and you will not hear the clicks.
You will need to do a bit of diagnosis before replacing all of the glow plug system as it could just be the temp sensor!
Hope this helps

[jaggedfish]

Thanks all for your input thus far! I am leaning towards the temp sensor issue too as I had the van in to CVI for Delica Tune, oil change, IP rebuild and general check over prior to relocating to Calgary. All filters replaced recently, all was in good working order prior to my road trip.

I am definitely getting the clicks... first cycle is about half of the usual cycle... if I cycle the glow again immediately the second click comes within half a second of the first. Would seem as tho the van thinks it's already warm. Also, once the van IS warm and I can start it easily, the glow circuit cycles a lot for the first 30 seconds or so of the engine running then they stop.

Is there a way of temporarily bypassing the glow circuit with a manual push button until I can get a new temp sensor? Can the temp sensor be tested?

Many thanks again for your continued help!
Cheers!
Ian

[jaggedfish]

Okay... soooo... got my temperature sensor from CC Auto - thanks very much guys! - installed it and... same problem.

Now going on the advice of those in the know, this should mean that I have a glow plug problem and replacing them should solve my issue. Question is... is there anywhere in Calgary I can get glow plugs quickly?

I am more than willing to go thru CC Auto again but I am hoping to get them quickly (like tomorrow). If I can source them here in Calgary that would ease some of my stress. Otherwise, I am hoping I will be able to get the guys at CCA tomorrow....

Any suggestions?
Thanks again!

[Rising Sun Auto Import]

As I said, it could be a control unit problem from my experience.
Of course it is good to replace glow plugs when you get a service for control unit system.
But main problem should be the faulty glow plug control system.
Do not waste money.
Unfortunately we don't sell control unit itself as it need a little modification.
Today is the final day for Assiniboine huge blow out sale event ( delica parts )
Hoping this helps.

[snelson]

When I replaced mine a little over a year ago, I bought them in Calgary at the Napa located close to Crowfoot shopping centre. It's not in the shopping centre but actually in Ranchlands - that being said, any Napa will do I would think.

I pulled the part number off the site here and called around, found them and replaced them in about 10 minutes. Be sure to use some of that thread stuff so they don't seize in there, also be careful removing the old ones and try to remove them with the engine cold.....what a difference once replaced. My van started up so much easier, and still does - the old ones I pulled out were a mix of blue and green tops.

I have a manual glow plug button that the previous owner installed, and I know others here will say that it's better to replace/fix the control board unit - but in my experience a push button is WAAAAY better. I never EVER have smoke, even on cold winter mornings (though I do use a block heater too), I just hold the button for 5 seconds, put my seat belt on, hold for another 4 maybe and start her up without touching the pedal, without using the throttle lock thingy. It's been great. And on really cold mornings, I can give the plugs a few more quick zaps if the engine is chugging.

Say what you will about manual glow plug systems, I think it's the cats ass.

[jaggedfish]

Hey thanks SNelson! I will get on the horn this morning and track them down. Graham (sp?) at CC Auto was telling me the glow plugs must be the ones with the green tops - they are 6 volt plugs. He said a lot of plugs are replaced with the incorrect 12 volt ones. Obviously you had a mix. I am curious where your push button is wired to - any way of telling?

I haven't fully discounted the ECU but I have been advised that because I still get the clicks - albeit at shorter intervals - that the problem would likely be the temperature sensor (now replaced) or a bad glow plug or two. A failed ECU would result in no clicks at all.

Cheers!
Ian

[snelson]

Excellent, let us know if replacing them does in fact cure your ECU.

This thread here makes mention of the part number from napa, but I'm sure you're already found it...
http://www.delica.ca/forum/glow-plug-pa ... tml#p29186

My manual switch is connected to the ECU as I still here the click behind my head when I flick it on, but other than that I'm not sure how it was done. Perhaps I'll trace everything down sometime and post what I find.

Not sure the plugs HAVE to be the green ones, though John knows way more than I would. Just seems it depends on your year, but the NGK ones work excellent for me and others here.

[jaggedfish]

Cool! Thanks again snelson!

A note to this... checked with Napa and they quoted me $55 per plug for the NGK ones!

Don't think they have to have green tops either as long as they are 6-volt.

Will post results once I have replaced glow plugs. Will be ordering from CC Auto as they will still be cheaper with shipping included....

[jaggedfish]

Okay... so, to update the situation...

My new glow plugs arrived yesterday frm CC Auto (thanks guys!) and I replaced the old ones with no issues, cleaned the contacts on the leads from the solenoids and the bus bar and then gave the system a few cycles. Seems like it made a MAJOR difference. The glow cycle is back to a longer cycle now (what it should be). A quick re-cycle results in about a half-cycle (4 seconds or so) and if I wait about 15 seconds, it returns to the longer cycle. There were no extra "clicks" from the solenoids any more after starting the engine either.

The big test, of course, will be this morning with a cold engine but it certainly seems that the glow plugs were the cause of the cycling problem.

It seems that a dead glow plug results in less draw on the electrical system which makes the ECU think the engine is warm when it is not as the good glow plugs heat up faster. The result is the engine not starting due to a "dead" cyclinder (or two) which will eventually "catch" with extended cranking of the motor which will get you out of a pinch but I wouldn't recommend doing that a lot. In the interim, I was plugging in the block heater to keep the engine warmer which made for a much easier start in the morning.

I hope this helps others diagnose issues in the future...
Cheers!
Ian

[Adrock]

From an electrical point of view the problem makes sense. I have no understanding of how a glow plug system actually works, but if I could make some assumptions (as in correct me if I'm wrong) I may be able to explain it.

If the glow plugs are 6 volt I would assume 2 are wired in series, (or does the controller divide the voltage and run them all parallel?) If wired in series, and one is shorting it will not drop 6 volts across each but rather 12 across the one remaining with resistance. Meaning it will heat up 4 times faster, and if your temp sensor is in that neighbourhood, it will function correctly. Again I am assuming the temp sensor measures temperature from one location rather than at all the glow plugs, and may be wrong.

[Green1]

I think it would have to depend on which plugs were "dead", if the plug closest to the sensor was dead, the controller would assume the engine wasn't warming up, and would run them longer, if the plug farthest from the sensor is dead, the other plugs would warm up faster, causing the sensor to detect heat earlier, and the controller to shorten the cycle....

Just a guess though, but it seems to track...