Buzzing during starting ( glowplug ecu issue? )

[mrraulduke]

Hello,
I've had my van for almost 2 years now.
I bought a van that had been intitally serviced at CCA and it's been great.
I've done normal maintenance, it doesn't get driven a lot.

However for the past few days it seems like the glowplugs have not been working. They were replaced last year in march due 2 of the 4 old ones not working. The van has always started like a dream, cranked over after the relay click, even with 2 working glowplugs, there was only bucking afterwards.

So now the van cranks over just fine, it just doesn't start ( nicely! .. it will start just cranking the thing for a bit ). I have a strange new buzzing noise now under the dash with the key in the on position during glowplug warmup. I can still hear the glowplug relay click ~5 seconds after the key is on .. but it's not doing it's job.

the connection to the busbar is tight, as well as the glowplug-busbar connection.

i haven't been able to pinpoint the buzz noise, as after a few times it stops ( and the relay click stops as well.)

could this buzz be from the glowplug ECU? has anyone else had this problem?

Thanks in advance.

[Big-Bird]

I have had the clicking relays you speak of and sourced my problem to a pair of narrow relays that reside on the steering column just a few inches south of the plastic cover. (sorta shin height as you sit in the driver's seat) One of them was clicking like crazy when it was really cold. I also had the crappy starting issue but my glow plug relay behaved normally.

My glow plugs were changed in early September and in late November 2 of them quit working and the other 2 had marginal performance. The resistance check of the 'so-so ones' showed they were at 50% of what they should have been so they would not get very hot at all.

I cleaned the clicking relay's connections with a scuff pad and coated with di-electric grease. That problem went away.
Then I installed 4 new G.P.'s that have a 2 year warranty from Mardy at Amazing Auto and the crap-start issue was also resolved.

Pull the G.P.'s and do a resistance check on each one to verify the plugs are all working properly. GP's go with no warning, always a good plan to have a spare set on hand.

Since you're on the island you could call Commbs or Rocky Mountain Imports to get new plus shipped fast...that is if you need new ones.

[mrraulduke]

i never did pull my plugs to see if they were ok.
I think they are still good, as i started great through the cold snap we had, and i have only had the crappy starting since the buzzing ( not clicking .. more of a low high pitched high frequency buzz ). i can still hear my main relay click off after 5-6 seconds during startup.

when i had bad plugs, i did not have an increase buzz / click. just a lot of bucking / rough idle.

i'll look for the buzz under the steering column next.

[mrraulduke]

ugg...
i hate electrical gremlins.

So. i toke everything apart, tightened, cleaned connections. i did not test glowplugs.
I still get some buzzing somewhere ( does not seem to be in the drivers compartment / under the steering column ) but it starts normally. no bucking, no smoke, first crank after the glowplug click.

the buzzing stops after it is started. maybe it was the rains, 60 kms of bumpy logging roads, 45 cms snow.

snow van.jpg (173.59 KiB) Viewed 3483 times

[Lapprentis]

I have had that Buzzing noise twince in my L300 Once after I put an unwired Fog light switch and the other time with restarting my Van after having unpluged the ECU. For sure under the dash, close to the steering wheel, not to say on its left side. Any idea ?
Lapprentis