Glowplug selection seems to be a common issue amongst many owners of classic indirect-injection diesel landcruisers.
While glow plug manufacturers/distributors put out "selection catalogs", most of these catalogs have accumulated numerous errors.
So as a solution, I've tried to put together an alternative selection method as a trial.
Models affected:
BJ40, BJ41, BJ42, BJ43, BJ44, BJ45, BJ46 (running B, 2B or 3B engines depending on the model)
BJ60 (running the 3B engine)
BJ70, BJ73, BJ75 (running the 3B engine)
HJ45, HJ47 (running the H or 2H engine respectively)
HJ60 (running the 2H engine)
HJ75 (running the 2H engine)
My selection method here is based on my belief that, apart from a few minor exceptions, these cruisers can use just 6 glow plugs in all. And I believe which one an individual cruiser should use depends simply on the battery power supply available (whether 12 or 24 volt) and on which type of pre-heat system is fitted. (Glow Controller, Fixed Delay, or Super Glow)
Anyway, here is my selection guide (from which I hope you can select the correct plug for your indirect injection diesel landcruiser):
BTW - The yellow type signifies "24 volt cruiser information".
12 Volt
Glow controller 8.5V
Toyota 19850-68030, NGK Y-128T, Denso DG234
APS 5013, EIKO GT208, JKT PT104, MAY PT104
Bosch GPT208, VSP PT104, Champion CH121, HKT PT104
Warning! While these plugs are CLAIMED to be equivalent to each other - their current-draw does vary from brand to brand and so unfortunately some of them may not glow your Controller properly!!! (See post #54 for further information.)
Here reduced-voltage is fed to the glowplug busbar via a dash-mounted glow controller during pre-heating. This glow controller (which consists of a coil of resistance-wire behind a viewing hole) gradually brightens to "red-hot" (or even to "bright orange" depending on the model) after 15 to 20 seconds to give a visual indication that your plugs are hot enough for you to start cranking your engine.
Fixed delay 10.5V
Toyota 19850-68010, NGK Y-147T, Denso DG232
Bosch GPT218, Champion CH133, HKT PT 145
Here the busbar receives approximately the full battery voltage during pre-heating (because no glow controller or other type of resistor is fitted upstream). There is a glow-light (pre-heat light) on the dashboard that illuminates during pre-heating and extinguishes after a fixed time delay of between 15 and 20 seconds to tell you when to start cranking.
Owners often create a similar set-up that requires the same plugs (where the busbar again gets connected directly to the battery without any resistance device fitted inbetween) when their factory-wired pre-heating systems become troublesome. In such cases the dash-mounted momentary switch used to manually energize the glowplug busbar is commonly referred to as a “Wilson Switch”. And because no timer is used, the driver must estimate the pre-heat duration themselves.
A big advantage here is that the Wilson Switch allows the driver to smooth out a rough cold-idle by providing "After Glow". (The Wilson Switch can be used to re-energise the busbar once the engine is running.)
Super glow 6V
Toyota 19850-68050 (or 68051), Denso DG220
Bosch GPT214, Champion CH125, HKT PT146
Here the Toyota engineers sped-up the pre-heating procedure by using faster heating plugs (lower voltage plugs). They also installed two stages of pre-heat, and automated both these pre-heating durations according to coolant/block temperature and other factors. The first stage connects the busbar directly to the battery (12V) and the second stage (after-glow) drops this voltage to somewhere close to the plugs nominal voltage (6V).
Like the "Fixed Delay system" there is again a glow light (pre-heat light) that is extinguished to tell you when to crank. However here it illuminates for a much shorter time. (Typically just 2 or 3 seconds.)
24 Volt
Glow controller 20.5V
Toyota 19850-68040, NGK Y-178T, Denso DG235
Bosch GPT207, Champion CH122, HKT PT109
Warning! While these plugs are CLAIMED to be equivalent to each other - their current-draw does vary from brand to brand and so some of them may not glow your Controller properly!!! (See post #54 for further information.)
Here reduced-voltage is fed to the glowplug busbar via a dash-mounted glow controller during pre-heating. This glow controller (which consists of a coil of resistance-wire behind a viewing hole) gradually brightens to "red-hot" (or even to "bright orange" depending on the model) after 15 to 20 seconds to give a visual indication that your plugs are hot enough for you to start cranking your engine.
Fixed delay 23V
Toyota 19850-68020, Denso DG233, EIKO GT213
Bosch GPT213, HKT PT108, MAY PT108, JKT PT108,
Here the busbar receives approximately the full battery voltage during pre-heating (because no glow controller or other type of resistor is fitted upstream). There is a glow-light (pre-heat light) on the dashboard that illuminates during pre-heating and extinguishes after a fixed time delay of between 15 and 20 seconds to tell you when to start cranking.
Owners often create a similar set-up that requires the same plugs (where the busbar again gets connected directly to the battery without any resistance device fitted inbetween) when their factory-wired pre-heating systems become troublesome. In such cases the dash-mounted momentary switch used to manually energize the glowplug busbar is commonly referred to as a “Wilson Switch”. And because no timer is used, the driver must estimate the pre-heat duration themselves.
A big advantage here is that the Wilson Switch allows the driver to smooth out a rough cold-idle by providing "After Glow". (The Wilson Switch can be used to re-energise the busbar once the engine is running.)
Super glow 14V
Toyota 19850-68060, NGK Y-197R, Denso DG222
Bosch GPT217, Champion CH104, HKT PT141
Here the Toyota engineers sped-up the pre-heating procedure by using faster heating plugs (lower voltage plugs). They also installed two stages of pre-heat, and automated both these pre-heating durations according to coolant/block temperature and other factors. The first stage connects the busbar directly to the battery (24V) and the second stage (after-glow) drops this voltage to somewhere close to the plugs nominal voltage (14V).
Like the "Fixed Delay system" there is again a glow light (pre-heat light) that is extinguished to tell you when to crank. However here it illuminates for a much shorter time. (Typically just 2 or 3 seconds.)
Exceptions:
Toyota lists Aug 1988 to Jan 1990 12V BJ70, BJ73, HJ60, and HJ75 cruisers as running 11V plugs (Part number 19850-64031)
Originally I had listed more "exceptions" here (copied from various plug catalogs) but my research of the Toyota EPC didn't clearly back them up.
However I suspect pre-1975/76 diesels (BJ40 & HJ45) may not comply with this guide. But even then, non-compliance may really be limited to simply pre-June 1973 HJ45 (H) models ---- My research isn't conclusive.
Note:
If anyone at all (not just the owners of pre 1975/76 diesels) finds their engine doesn't run the plugs in this guide ... then PLEASE add a post to this thread so we can work out why (and so we can have real evidence for others to take note of).
This thread is basically about "factory wiring". But even if a previous owner has tampered with it, I'm hoping information here will still offer useful guidance.
As far as I know, all of the very early diesels ran "Glow Controller pre-heat" and this form of pre-heat ceased for most models in late 1982 (but may have remained in some till late 1984) when Fixed Delay and Super Glow took over.
While glow plug manufacturers/distributors put out "selection catalogs", most of these catalogs have accumulated numerous errors.
So as a solution, I've tried to put together an alternative selection method as a trial.
Models affected:
BJ40, BJ41, BJ42, BJ43, BJ44, BJ45, BJ46 (running B, 2B or 3B engines depending on the model)
BJ60 (running the 3B engine)
BJ70, BJ73, BJ75 (running the 3B engine)
HJ45, HJ47 (running the H or 2H engine respectively)
HJ60 (running the 2H engine)
HJ75 (running the 2H engine)
My selection method here is based on my belief that, apart from a few minor exceptions, these cruisers can use just 6 glow plugs in all. And I believe which one an individual cruiser should use depends simply on the battery power supply available (whether 12 or 24 volt) and on which type of pre-heat system is fitted. (Glow Controller, Fixed Delay, or Super Glow)
Anyway, here is my selection guide (from which I hope you can select the correct plug for your indirect injection diesel landcruiser):
Guide to glow plug selection
BTW - The yellow type signifies "24 volt cruiser information".
12 Volt
Glow controller 8.5V
Toyota 19850-68030, NGK Y-128T, Denso DG234
APS 5013, EIKO GT208, JKT PT104, MAY PT104
Bosch GPT208, VSP PT104, Champion CH121, HKT PT104
Warning! While these plugs are CLAIMED to be equivalent to each other - their current-draw does vary from brand to brand and so unfortunately some of them may not glow your Controller properly!!! (See post #54 for further information.)
Here reduced-voltage is fed to the glowplug busbar via a dash-mounted glow controller during pre-heating. This glow controller (which consists of a coil of resistance-wire behind a viewing hole) gradually brightens to "red-hot" (or even to "bright orange" depending on the model) after 15 to 20 seconds to give a visual indication that your plugs are hot enough for you to start cranking your engine.
Fixed delay 10.5V
Toyota 19850-68010, NGK Y-147T, Denso DG232
Bosch GPT218, Champion CH133, HKT PT 145
Here the busbar receives approximately the full battery voltage during pre-heating (because no glow controller or other type of resistor is fitted upstream). There is a glow-light (pre-heat light) on the dashboard that illuminates during pre-heating and extinguishes after a fixed time delay of between 15 and 20 seconds to tell you when to start cranking.
Owners often create a similar set-up that requires the same plugs (where the busbar again gets connected directly to the battery without any resistance device fitted inbetween) when their factory-wired pre-heating systems become troublesome. In such cases the dash-mounted momentary switch used to manually energize the glowplug busbar is commonly referred to as a “Wilson Switch”. And because no timer is used, the driver must estimate the pre-heat duration themselves.
A big advantage here is that the Wilson Switch allows the driver to smooth out a rough cold-idle by providing "After Glow". (The Wilson Switch can be used to re-energise the busbar once the engine is running.)
Super glow 6V
Toyota 19850-68050 (or 68051), Denso DG220
Bosch GPT214, Champion CH125, HKT PT146
Here the Toyota engineers sped-up the pre-heating procedure by using faster heating plugs (lower voltage plugs). They also installed two stages of pre-heat, and automated both these pre-heating durations according to coolant/block temperature and other factors. The first stage connects the busbar directly to the battery (12V) and the second stage (after-glow) drops this voltage to somewhere close to the plugs nominal voltage (6V).
Like the "Fixed Delay system" there is again a glow light (pre-heat light) that is extinguished to tell you when to crank. However here it illuminates for a much shorter time. (Typically just 2 or 3 seconds.)
24 Volt
Glow controller 20.5V
Toyota 19850-68040, NGK Y-178T, Denso DG235
Bosch GPT207, Champion CH122, HKT PT109
Warning! While these plugs are CLAIMED to be equivalent to each other - their current-draw does vary from brand to brand and so some of them may not glow your Controller properly!!! (See post #54 for further information.)
Here reduced-voltage is fed to the glowplug busbar via a dash-mounted glow controller during pre-heating. This glow controller (which consists of a coil of resistance-wire behind a viewing hole) gradually brightens to "red-hot" (or even to "bright orange" depending on the model) after 15 to 20 seconds to give a visual indication that your plugs are hot enough for you to start cranking your engine.
Fixed delay 23V
Toyota 19850-68020, Denso DG233, EIKO GT213
Bosch GPT213, HKT PT108, MAY PT108, JKT PT108,
Here the busbar receives approximately the full battery voltage during pre-heating (because no glow controller or other type of resistor is fitted upstream). There is a glow-light (pre-heat light) on the dashboard that illuminates during pre-heating and extinguishes after a fixed time delay of between 15 and 20 seconds to tell you when to start cranking.
Owners often create a similar set-up that requires the same plugs (where the busbar again gets connected directly to the battery without any resistance device fitted inbetween) when their factory-wired pre-heating systems become troublesome. In such cases the dash-mounted momentary switch used to manually energize the glowplug busbar is commonly referred to as a “Wilson Switch”. And because no timer is used, the driver must estimate the pre-heat duration themselves.
A big advantage here is that the Wilson Switch allows the driver to smooth out a rough cold-idle by providing "After Glow". (The Wilson Switch can be used to re-energise the busbar once the engine is running.)
Super glow 14V
Toyota 19850-68060, NGK Y-197R, Denso DG222
Bosch GPT217, Champion CH104, HKT PT141
Here the Toyota engineers sped-up the pre-heating procedure by using faster heating plugs (lower voltage plugs). They also installed two stages of pre-heat, and automated both these pre-heating durations according to coolant/block temperature and other factors. The first stage connects the busbar directly to the battery (24V) and the second stage (after-glow) drops this voltage to somewhere close to the plugs nominal voltage (14V).
Like the "Fixed Delay system" there is again a glow light (pre-heat light) that is extinguished to tell you when to crank. However here it illuminates for a much shorter time. (Typically just 2 or 3 seconds.)
Exceptions:
Toyota lists Aug 1988 to Jan 1990 12V BJ70, BJ73, HJ60, and HJ75 cruisers as running 11V plugs (Part number 19850-64031)
Originally I had listed more "exceptions" here (copied from various plug catalogs) but my research of the Toyota EPC didn't clearly back them up.
However I suspect pre-1975/76 diesels (BJ40 & HJ45) may not comply with this guide. But even then, non-compliance may really be limited to simply pre-June 1973 HJ45 (H) models ---- My research isn't conclusive.
Note:
If anyone at all (not just the owners of pre 1975/76 diesels) finds their engine doesn't run the plugs in this guide ... then PLEASE add a post to this thread so we can work out why (and so we can have real evidence for others to take note of).
This thread is basically about "factory wiring". But even if a previous owner has tampered with it, I'm hoping information here will still offer useful guidance.
As far as I know, all of the very early diesels ran "Glow Controller pre-heat" and this form of pre-heat ceased for most models in late 1982 (but may have remained in some till late 1984) when Fixed Delay and Super Glow took over.
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