12v Aust HJ75 Wilson switch install question

[Sixty's Guy]

I would be checking the glow plugs. Remove the rail that connects to all glow plugs and then check continuity between earth and the top of the glow plug. If any read OL or massive reisstance they are buggered. If any of them are buggered, replace all of them and use the good ones as spares. I have used cheap ones off ebay (about $45 for 6 - can't remember the brand, but they come in a yellow and black cardboard box) and they last just as well as Bosch plugs ($30 each).

 

[Hillynath]

Hey Sixties, thanks for your reply,

Whilst I had it apart I was going to replace the glow plugs but we were a bit short for time so I didn't bother, and since then I haven't bothered pulling the rail.

When I get some time on Saturday ill check them out.

Another theory I have is that, the glow plugs are only on for 30-40 seconds, and yet the running rough and white smoke continues for 1-2 minutes, with no change around the time that the after glow switches off? which makes me think it could be elsewhere.

Do you know if the injection pumps perhaps have a cold start setting?

 

[Hillynath]

Alright so I had a play with it and pulled all the glow plugs, put them on the bench with some jumper cables and they're all heating fine, checked cold and hot resistance and they all were good.

I did notice on 2 of them when I pulled them out they were a little wet with diesel on them... This is after it sitting for a night and not being ran at all.

So even though I replaced the injectors less than 2000km ago, I'm hoping that a couple of them aren't leaking. In theory if 2 are leaking diesel into the cylinder overnight, when I start it up that could explain it running rough and the excessive smoke. I know its unlikely with new injectors but that makes sense to me.

Time to pull those bastards off again!

 

[Hillynath]

Before pulling the injectors I decided to instead do a little more diagnosis. I ran it around town on a few errands and once I got home, as soon as I turned it off I went along and cracked open all the injector lines to relieve the pressure then did them up again. So in turn if the injectors are weeping, this should stop that, and therefore give me reason to pull them out.

Tomorrow morning when I start it I shall see what happens.

 

[Hillynath]

So it's been a little while, I've been flat out with work and whatnot.

After cracking each line to relieve pressure it didn't change how it ran. Not knowing when the glow plugs were last changed I went and got some, $80 for 6 Bosch ones.

Still no luck with new plugs.

Kind of running out of things to look for, it's doing my head in

 

[sodafeld1]

BTW, are you sure it is the timer that is faulty? I had starting issues in that in was running rough on start up and blowing a lot of white smoke. I researched quite a bit and I think a lot of people use the wilson switch without fully diagnosing the problem.

I checked the voltage at the glow plugs and found only 6 volts initially and then 3 volts on the after glow. I tracked the low voltage back to the 'glow plug current sensor' (part #28631-68020) and the 'current sensor plate' (part #28624-68011). There was approximately a 3 volt drop across these. I couldn't locate aftermarket items, so had to go with genuine Toyota - the local Toyota dealer had them in stock.

I now have just under 10 volts at the glow plugs initially and around 4.5 volts on afterglow. Unexpectedly the first glow comes on for around double the time that it did before. End result is that it starts a lot better and the white smoke has almost completely dissapeared.

Current Sensor old vs new

Another pic of old vs new - the ols one was burnt out/corroded.

Sensor plate ends old vs new - easy to see where the voltage drop came from!

Do you know why these would corrode/ burn out? I have exactly the same circumstance, bit worse. Initially I thought it was an old battery without enough kick, so she was happy with a new battery for a while, but, the same click click came back. Hunted around and found this same problem.. Could it be too much starting and switching off the engine? Too much carbon build up on old glow plugs? Too much starting on a battery with not enough kick? Has it happened again? I ordered the same part, allfourx4 cheaper than donkyatt, still a bit exy tho for a little piece of metal. Thank you for your post.

 

[sodafeld1]

Do you know why these would corrode/ burn out? I have exactly the same circumstance, bit worse. Initially I thought it was an old battery without enough kick, so she was happy with a new battery for a while, but, the same click click came back. Hunted around and found this same problem.. Could it be too much starting and switching off the engine? Too much carbon build up on old glow plugs? Too much starting on a battery with not enough kick? Has it happened again? I ordered the same part, allfourx4 cheaper than donkyatt, still a bit exy tho for a little piece of metal. Thank you for your post.

(current sensor strap that is)