Pulsing electrical issue

Captain America · Post by **Captain America** » Thu Jan 12, 2017 10:14 am

Hi all,
I'm sure this subject has been touched on here on the forum but, I want to be specific.
The facts: Started van this morning and warmed it up in 50f weather. Started out for a 10 mile drive to the airport. Along the way I put the defroster on full blast with headlights on as well. Early on I noticed the defroster intensity surging or pulsing along with the headlights dimming at the same time as well. The relay in the pillar was also clicking along in unison with the above issues. Temp stayed at below half. I have new Gates belts that squeak as well even aft 1000 miles. Can you help me with a diagnosis?

Regards

Post by **Growlerbearnz** » Thu Jan 12, 2017 1:22 pm

That's your glow plugs cycling to keep the engine running properly until it warms up. You notice it more when there's a lot of electrical load.

Before the engine starts the plugs are powered with 12V to heat them up quickly, once the engine is idling the plugs switch to 6V until the engine's warm enough. If you start driving (engine speed above 1000rpm) the plugs will still run at 6V but will cycle on and off. It should stop after a minute or so (usually quicker).

Reasons it would continue longer than usual are a stuck open thermostat (leading to a slow engine warmup), or a failing temperature sensor (telling lies to the ECU so it thinks the engine's colder than it is).

You can help it by setting your idle speed to 1100rpm while it's warming up- that'll help the alternator replenish the battery quicker and will reduce the voltage drop when all the electrical things are running at the same time. Once the clicking stops you can return the idle speed to normal.

Captain America · Post by **Captain America** » Fri Jan 13, 2017 3:58 pm

Bear,
Thank you for the concise explanation. I just replaced my water pump and added a fresh thermostat so I'm leaning towards the sensor being the culprit. Is there a chance the ecu is fouling and if so is this a repairable item or full replacement? Thank you again.

Post by **Growlerbearnz** » Fri Jan 13, 2017 4:14 pm

The ECU is known to fail from age. There are a couple of capacitors on the board which leak and corrode the traces, or a failure of one of the solenoids can burn out traces on the board. It's easily repairable- replace the faulty component(s), rebuild the traces with wire and solder. Check out the ECU threads in the Technical Reference Library.

That said, your failure is uncharacteristically subtle. Maybe it's in the early stages, but I'd replace the temperature sender first (the two wire one on top of the head, near #1 fuel injector). It's a common part- search for a recent discussion of it.

Post by **FalcoColumbarius** » Fri Jan 13, 2017 10:15 pm

Growlerbearnz wrote:The ECU is known to fail from age. There are a couple of capacitors on the board which leak and corrode the traces, or a failure of one of the solenoids can burn out traces on the board. It's easily repairable- replace the faulty component(s), rebuild the traces with wire and solder. Check out the ECU threads in the Technical Reference Library.

That said, your failure is uncharacteristically subtle. Maybe it's in the early stages, but I'd replace the temperature sender first (the two wire one on top of the head, near #1 fuel injector). It's a common part- search for a recent discussion of it.

My '92 ECU had a melt down (couple of capacitors got ignition and tried to blast off, couple of craters in the PC board). In the meantime I put in a "manual override" until I got it fixed. During that time I came across a '91 ECU: Same box, same number, same everything until you opened the box up. My '92 ECU had a green PC board with silver traces, &c., where the '91 ECU has a brown board and instead of traces it has, like, thick wires. It looks way more skukum than the other so I've left it in. Also, everything is aligned on the other axis, which I thought was interesting.

Anyway, just an observation I thought might be useful to this thread.

Falco.

Captain America · Post by **Captain America** » Sun Jan 15, 2017 9:47 am

If I end up having to investigate/repair my ECU where would I take it for service? What kind of business is specific to this repair? Thank you guys for your direction.

Post by **Growlerbearnz** » Sun Jan 15, 2017 12:54 pm

LOL! You haven't looked at the ECU threads in the Technical Reference Library yet, have you?

"Super-quick glow ECU technical details" (http://www.delica.ca/forum/viewtopic.php?f=94&t=18005) has a link to Wings Electronics, where Daniel will be happy to rebuild your ECU if you're not brave enough.

Captain America · Post by **Captain America** » Sun Jan 15, 2017 4:23 pm

Lol!!!!!! Anything with the initials ECU makes me quiver. Gives me the feeling a impending doom and inadequacy.
Kinda like women! Lol just can't wait to crack the ECU "volumes".

Post by **FalcoColumbarius** » Mon Jan 16, 2017 3:16 pm

Captain America wrote:Lol!!!!!! Anything with the initials ECU makes me quiver. Gives me the feeling a impending doom and inadequacy.
Kinda like women! Lol just can't wait to crack the ECU "volumes".

I think you mean "Impeding doom", no?

Falco.

Captain America · Post by **Captain America** » Mon Jan 16, 2017 7:51 pm

Lol!!!

Delica Poetry
I will be "impeding" myself from tackling this ECU issue by practicing "ignorance is bliss" as the spectre of burnt glow plugs circles my head with impending doom.

Both work in this instance! Lol

Taking my bow.