Glow Plugs

[Clarky]

I don't recommend NGK pugs. I used them and now have one stuck in the left head.

[robertodonnell]

I will be buying Bosch.

https://www.ebay.com.au/itm/6-Bosch-...o/401065983431

[robertodonnell]

So I've done some testing.

Plug # 1 definitely dead as it reads open circuit on the meter, and plugs are definitely rated at 4.4 volts.

I tested the glow voltage on plug 4. Turn key on and it's reading full voltage (pegs out on 2.5 volt scale on analog meter) for about a second, then it drops to a constant 0.5 volts for as long as I had the key on. This seems a very low glow period, maybe a dodgy GP module?

I pulled a plug to test glow. The plug definitely got hot. Not red hot, but hot enough to leave a burn on my finger like I'd grabbed a soldering iron tip!

Now, here's the curious part - oily residue on the plug before the first glow attempt. Haven't run the Jeep today but it had a good 30 km run yesterday. This residue all but burnt off while glowing. Pic of this attached. Would this be leaking injectors? After it sits cold overnight she takes ages to fire, and sometimes several cranking events. When she finally fires there's a plume of white smoke out back. Never a problem starting in the arvo if it's driven in the morning and then started again in the evening, but the cold morning starts are always difficult. Never a problem in warm weather either, last year's winter FNQ trip vindicated this.

So, thoughts?

Cheers,

Robert

Sent from my G8141 using Tapatalk

[cherokee94nz]

A blue driver will tell you if the glow plugs are bad, will even tell you what one is not working. And will also tell you if the module is playing up. Best $100 i have ever spent.

[robertodonnell]

Yes, I have one. That's how I knew the #1 plug was dead. It has come up with no other faults. That's why I am curious about the injectors.

[Clarky]

Do you still have your old glow plug module?

There is a repair that can be done to fix the fusible wires inside (the most common reason for failure). If your current module is playing up this is a cheap and easy way to find out.

https://youtu.be/axvc-QUTQFY

You Tube

When my injectors needed replacing it was stalling, starting wasn't an issue.

[robertodonnell]

Sorry Clarky I typed a reponse to your post above, it must have failed uploading.

I have replaced the plugs with Bosch ones. Car starts straight up cold now!

The new plugs glow bright red, while the other ones smouldered like a soldering iron. Both new and old were marked 4.4v, but the old ones glow the same bright red when connected direct to a 12v battery, so my guess is they were incorrectly marked and are actually 11v ones from a Sprinter.

At any rate, that's what you get for buying a brand name you've never heard of.