Image Image

4JB1 (marinised) Glow Plug wiring / relay

Get help fixing your Isuzu from other club members
Post Reply
Victorthesailor
Posts: 1
Joined: Mon May 28, 2018 3:11 am

4JB1 (marinised) Glow Plug wiring / relay

Post by Victorthesailor »

I have a marinised 4JB1 in my 1992 yacht recently purchased. I replaced the glow plugs today going through the motions of fault finding excessive fuel-rich white smoke. I realized that they are not terminated to a positive wire whatsoever. There is a glow plug plate that connects the glow plugs in series but its not fed my anything.

New Zealand gets real cold in the winter so glow plugs are required. I'm not an auto electrician so any help by way of photos or 'sketches for dummies' will be very much appreciated.

I've attached a image of the glow plug plate from the service manual (the manual does not show me what this should be connected to)

Thanks in advance.
Vic
User avatar
geeves
Posts: 1980
Joined: Mon May 11, 2009 1:56 am

Re: 4JB1 (marinised) Glow Plug wiring / relay

Post by geeves »

A non standard setup and an engine that doesnt really care about glow plugs. The normal set up gives 0.5 seconds of glow unless the coolant is below 5C in which case it gives 30 seconds.Also timing is advanced while this low temperature exists. You very likely dont have the wiring loom to wire like factory but auto shops do sell glow plug timers aftermarket which activate via a switch. You could set this up and just remember at winter time you need to push the switch. (really you only need it on very cold Auckland winter days which you might not be using the boat anyway)
Sickmind
Posts: 1
Joined: Wed Dec 26, 2018 5:51 am

Re: 4JB1 (marinised) Glow Plug wiring / relay

Post by Sickmind »

You will need a lot of parts to build the original glow system, like temp sensors QoS controler, some relays.. etc. The best for you will be aftermarket glow system, or if you want to do it in very easy and simple way use one button which goes trough relay and then direct to this plate of the glow plugs. In this way just keep the button for 10-15 seconds when it's cold and then start the engine and release the button. You can also think to advance the timing on the pump when its cold, again it can be done by a button or a switch (it will no need a relay in this case).
Here you can read about this time advancing:
Cold-Start Device - CSD (Automatic)

There are different types of automatic CSDs available for the VE injection pump. One popular type is the vacuum-operated CSD that uses a vacuum pump, water thermo valve, and a dual-stage diaphragm located on the injection pump, Figure 24. The thermo valve, Figure 25, applies vacuum to the diaphragm(s), depending on coolant temperature. (Figure 26 shows which diaphragms have vacuum applied at various temperatures.)

Another CSD, called the KSB (a Bosch designation), advances injection timing by controlling supply-pump pressure. A KSB control valvemounted on the side of the pump overrides the pressure regulator, increasing supply-pump pressure and advancing injection timing. For example, if the temperature is below the set value of the temperature switch, the switch closes and the KSB solenoid switches on. This increses pump pressure. Above a preset value, the temperature switch opens, the KSB solenoid opens, and the pressure regulator now controls supply-pump pressure.
Post Reply