3B Glow Plug / Cold Start Mystery (1 Viewer)

[code 621]

Greetings fellow diesel enthusiast, I am posed with a cold start issue that I have been working my way through. I am in the final stages of a '84 BJ60 / '84 FJ60 3B swap-n-refresh. The Injectors were rebuilt at GCL in Edmonton. The glow plugs are new (NGK 7493-Y-147T). There is voltage to the bus bar and voltage from the tops of the glow plugs. The Wilson switch, wired as per Greg_B's Manual switch Bypass thread, was previously working w/ the NGK plugs listed. The engine will start only after heating the block with the lower rad hose heater. Once at 180* it will start with the slightest crank / bump of the key.
This forum has guided me through all sorts of questions during this swap but this problem has me stumped.
Thanks, Joe

 

[code 621]

I thought that I might have an air leek in the fuel system since I switched to a double filter set up and when I bleed at the 2nd fitter head there were very fine bubbles. I replaced the clamps and checked the hose to fuel line connections. Much pumping and bleeding followed. It still wouldn't fire. I plugged in the rad heater for 10 minutes and off it went. Started right up. I did a bunch more bleeding while it was running.
Any thoughts?

 

[cruisedeisel]

Crank speed has alot to do with how fast your engine starts when its cold. I added grounds to my side posts on my batteries and that helped alot.

Whats the voltage at the bus bar and glow plugs?

 

[code 621]

Thanks for that question CD--I went back and re-metered and found that from the top of the glow plug and chassis there is no voltage but from top of glow plug to the lower bar there is 14.4 V. I have a grounding issue. I attached photo of how that lower bar is wired. I must have that assembly wrong.

 

[cruisedeisel]

You have to go by the book for that one. Just remember that you don't ground any of the bus bar. You glow plugs are the resistors which are..... GROUNDED.

 

[lostmarbles]

T... I must have that assembly wrong.....

Yes. You've still got some of the old superglow stuff in place there that needs to go.

With a simple Wilson set-up using those new 10.5V plugs, you simply need a busbar connecting the tops of all four plugs together and then you attach the thick wire from your relay (supplying the 12V preheat current) to that busbar.

The dropping resistor and the voltage sensor I see in your picture are all now superfluous.

 

[code 621]

STILL NO GO

attach the thick wire from your relay (supplying the 12V preheat current) to that busbar.

You've still got some of the old superglow stuff in place there that needs to go.

Thanks Tom. I removed the lighter gauge wire (dropping resistor?) from the post that the 12v from relay is connected to. I unplugged the voltage sensor wire (flat pins plugged to the lower bus bar).
..."attach the thick wire from your relay (supplying the 12V preheat current) to that busbar"...
I am not understanding the power flow. The 4 plug tops are connected by the upper bar. 12v comes in on the lower bar.

Thanks for the comment cruiserdiesel.

 

[lostmarbles]

...I am not understanding the power flow. The 4 plug tops are connected by the upper bar. 12v comes in on the lower bar.....

So you definitely have the correct 10.5V plugs for WILSON SWITCH preheat in a 12 volt cruiser?

Then the 12V thick wire simply attaches to the busbar and there should no longer be any upper or lower bars. (Just the one bar that connects all the plug tops together.)

As per this:

 

[code 621]

Now I (we ) could be getting some where. That's why I attached the photo from the passenger side--to try to show the space between the 2 bars. - and now that you say it like that I think its time to go back out to the garage and see what happens.

 

[code 621]

We have ignition!

Tom, Thanks for your help.

 

[lostmarbles]

Now I (we ) could be getting some where. That's why I attached the photo from the passenger side--to try to show the space between the 2 bars. - and now that you say it like that I think its time to go back out to the garage and see what happens. View attachment 1251576

I'd have gotten ridden of both of those "bars" to end up with simply the thick 12V feed wire (from the glow relay) attached to the "main glow plug busbar".

 

[jim land]

i just remove this tab (red arrow) and plug the big wire from the main glow relay to the first plug

 

[code 621]

Jim I do believe you have pointed out my assembly mistake. It didn't make sense to me that the connection was just the two bars simply touching. I probably won't be back under the hood until Saturday but I you have pointed out the last piece to the puzzle.