Which plugs should I be running - B, 2B, 3B, H and 2H diesels

[watrob]

Hi Rudi, started the 12ht this afternoon, all good. The power to the VSV works perfectly, the change from OI to D is not noticeable at all, engine shuts down immediately on ignition turn off.

The conversion to the 12HT engine fuel relay using the HJ47 wiring loom works with the incorporated low oil pressure shut down of the 2H oil pressure switch being installed on the 12HT engine.

Heat screen relay comes on with starter motor start, all seems to work ok, cold idle up works as does the power steering idle up, thanks for all your help with this.

 

[bj40green]

Happy

Rudi

 

[watrob]

Hi Rudi, Everything seems to work ok, but? the glow light which worked with HJ47 Pre-Heat Relay is not working with the 12HT relay. Pin 7 on the HJ47 relay becomes Pin 3 on the 12Ht Relay, the photo shows the R/B wire connected to pin 3

I am wondering if the difference between the HJ47 relay & the 12HT relay is that 12HT relay needs the metal outside canister earthed, my 40 is fibreglass and I am just trying to think if I ran a separate earth or not. As you are aware the glow light is also a plastic fitting, then there could be the fact the bulb is blown?

Suppose I will have to pull the plug off the 12HT relay and measure the wire connection from pin 3 to the glow light bulb socket, I know power is coming to the bulb from the ignition because the sediment filter light comes on ( are they on the same circuit), so it has to be between the bulb and the pin 3 wire connection on the a2HT relay plug, if the wire tests OK then it has to be an earth problem?

The light was working with the HJ47 relay ok? when the IG was turned on, I know the 12HT heat screen comes on when you turn the key to the start position (after heat) as I have measured the voltage, but the glow light should be on when the key is turned to IG and I do not have any volt at the heat screen on IG.


PS Rudi. I wonder if the Glow Engine fuse has blown, the second relay is running (after heat) on Start ( I have measure the voltage when key is turned to start) because it does not go thru the fuse, this would account for the light not working also? but do you know if the sediment filter light runs thru the same circuit & fuse as it works?

 

[bj40green]

Pffffft, where to start?
1. The relay should be grounded by pin 10. You can always ad a ground wire to the housing mounting bolts.
2. The IHIL (Intake Heater Indicator Light) is hooked up between 12V from pin 4 (Fuse Engine Glow) and pin 3. Pin 3 is low (ground) lamp is "on", or high (12V) lamp is "off". Check pin 4 for voltage.
3. Do you have pre-heat? Check voltage on pin 1 to pin G on the No.1 Intake Heater Relay.
4. If the Fuse Engine Glow is defective you don't have voltage on pin 4.
5. I've no, nada, zero, zilch experience with H engines and glow screens. All I can is read diagrams and figure out how it works.

Rudi

 

[watrob]

Ok, so I need to check pin 4 B/Y wire for voltage when key is in IG on position, as I understand the HJ47 wiring loom has a Starter Relay which means on Start it activates the second heat relay & starter motor via the starter relay

In the IG position power is feed thru the Ignition Relay (Rudi where is the ignition relay situated in the HJ & BJ's, is it bolted somewhere near the peddle box, I just don't remember seeing it) which then send 12 volts to the engine fuse, then onto the glow light then into pin 3 of the controller, power is also feed to pin 4, which send volts out pin 1 to the pre heat relay.

I have checked previously, I do not have IG voltage at the heat screen (but I do have voltage at the heat screen at Start "After Heat" which is a separate circuit)

The engine fuse is common to the glow light & pin 4 which activates the pre heat relay, but I do not have a wiring diagram. The thing is the sediment light comes on at IG, so I would like to find out if it in the same circuit as the glow light?

As far as I seen the sediment light gets its power from the 20A Heater fuse circuit, Rudi could you confirm this?

 

[bj40green]

The only diagram I have is this one and it's for glow plugs. There is no ignition relay in this diagram.

Rudi

 

[watrob]

Hi Rudi, I have investigated and there is no Ignition Relay on the HJ47 1984 wiring looms, only a Starter Relay which activates the second glow relay (after Glow). The IG is connected as far as I see directly to the Engine Fuse, from the engine fuse to pin 4 & the glow light.

The Bulb Check Relay works on the Brake & Sediment Filter light as they come on at IG and go off on Start, therefore they can not be getting there power off the Engine Fuse but rather the 20a Heater Fuse, Rudi your diagrams confirms this, but I see it has a Main Relay Optional, do you know what this is for? is this for manual Glow/

My ignition switch goes, Lock, Acc, On, Start, the ON is supposed to be pre heat and the Glow light comes on or did.

 

[bj40green]

Let's start with this diagram:

Do you have voltage on pin 4? If so, the power comes from somewhere else if there is no Ignition Main Relay.
No.2 after heat relay seems to work as you say when the key is in the start position, right?
Now to No.1 pre heat relay. This relay is activated by pin 1. Do you have voltage on pin 1? This voltage is controlled by the water temperature sensor and will be none, or very short, if the engine is warm/hot.
Do you have voltage on the B terminal on the No.1 pre heat relay?

Rudi

 

[watrob]

I will check those things, but your statement "This voltage is controlled by the water temperature sensor" got me thinking. I had to extend the cable to reach the temp sensor because its down low on the 12HT block whereas the temp sensor is on the front part of the head on a 2H.

Can you confirm my thinking as follows, if pin 7 wire goes to the temp sensor, then the other wire which returns (as its a 2 pin sensor) from the sensor which is earthed in the wiring loom somewhere............is this correct?

Then the pin 10 wire is earthed on the intake manifold, (see photo below). When engine is cold the temp sensor allows volts to pin 1, when warm the volts stop, correct? (I know its a thermistor)

Is the temp sensor subject to one pin is input and the other pin is output (meaning its directional or does it not matter?) does it matter if the wires got crossed?

 

[bj40green]

The thermistor is just a temperature sensitive resistor and is non-directional. When a sensor has 2 wires (terminals) none of them should be grounded to it's housing unless the sensor is defective (short to ground). So disconnect the sensor and check if one of the terminals has 0 ohm to housing. If so, check that the terminal that is grounded is connected to pin 10.

Then the pin 10 wire is earthed on the intake manifold, (see photo below). When engine is cold the temp sensor allows volts to pin 1, when warm the volts stop, correct?

I don't know if that's the right location for grounding. The diagram indicates that the sensor and pin 10 use a common ground point. In other words; that wire goes back to pin 10 and pin 10 is connected to ground.
If the sensor is grounded AND pin 10 is grounded (both to different locations) it would show like this pic. Two separate ground symbols, but by now we know that drawing diagrams is (or was) not Toyota's strongest point.

Rudi

 

[watrob]

Hi Rudi, the grounding of the water temp sensor is really the same wiring as on the 2H, both show the same grounding system, would be interesting to see where that return wire from the sensor goes because its not back to pin 10 on either the 12ht or the 2H wiring looms?

 

[bj40green]

Okay, so both diagrams are equal. An ohm test will show if it's ground or not.

Can we go back to posting #168 and answer my questions regarding the No.1 pre heat relay?

Do you have voltage on pin 4? If so, the power comes from somewhere else if there is no Ignition Main Relay.
No.2 after heat relay seems to work as you say when the key is in the start position, right?
Now to No.1 pre heat relay. This relay is activated by pin 1. Do you have voltage on pin 1? This voltage is controlled by the water temperature sensor and will be none, or very short, if the engine is warm/hot.
Do you have voltage on the B terminal on the No.1 pre heat relay?

Rudi

 

[watrob]

The 40 is permanently up at the Beach now so I will have to do those tests next week, the engine runs fine its just this pre heat wiring bug to fix.

Also going to reco the vacuum pump on the back of the alternator and I am swamping out the front coil springs with another set and pickup 25mm in height which will give me 145mm down travel and 125mm up travel, the front shocks had around 270mm of total travel.

 

[watrob]

Hi Rudi, got up to the house yesterday and replaced the vacuum pump on the back of the alternator. Started to measure voltages for pre-heat, everything seemed to checked out, turn the key to ON, heard the slight whistle, pre-heat worked, started engine.

I think what is happening is unless the engine is very cold pre-heat does not activate, only after heat. Once I started the engine for the first time pre-heat did not come on again. Would be interesting to see that the temperature setting is on the 12HT temp sensor switch compared to the 2H one?

 

[bj40green]

Sounds good to me! Congrats. The diagrams from the 2H and 12HT should tell you the difference.

Rudi

 

[watrob]

Hi Rudi, need your wisdom, the two turbo boost light vacuum switches which operate the low & high boost pressures lights (60 series with 12ht) work in such a way that at around 4-6 lbs boost the low pressure switch turns off (so it cuts 12 volt power to the green light), which is fine because that tells there is more than 6lbs boost, at idle the light comes back on because there is not enough pressure to turn then vac switch off.

My problem is the high pressure vac switch, the orange light is on all the time and does not turn off until and if I get to 15lbs boost, I need to reverse this so when 15lbs is reached and cuts the power at the vac switch the orange light comes on, warning me of over boost, question, would a Bulb Check Relay work for me as a reversed type of relay. That is when the power from the vac switch is on the relay is open ( no power to the orange light), when the vac switch turns off the relay closes the contacts and power flows to the light.?

 

[bj40green]

Any SPDT (Single Pole Double Throw) relay will do the trick.
So if your Bulb Check Relay is a SPDT model it should work.

Rudi

 

[watrob]

Thanks Rudi, that will work perfectly

 

[deaddrift]

For update to post #1 on this thread: All reference the 12V Superglow system where voltage starts at 12V and drops to 6V after a delay.

The correct Toyota part number is 19850-68051. Part number 19850-68050 is obsolete.
The Denso number I have found is 067100-1680.
The non-AU/NZ Bosch part number is 0 250 202 115. HEre is a specs pdf for this part: http://apps.bosch.com.au/AAExtranet_TechSearch/docs/TestData/GPT214.PDF


All of the Bosch part numbers I have seen take this format: 0 250 202 058 (NOTE that this is for a 12V --> 10.5V application, NOT the 12V-->6V Superglow.) All of the references I've found to Bosch part numbers that use "GPT" link back to an Australian or New Zealand supplier. I believe the digits-only part numbers are the right ones to use in the US and Europe.

HTH,
dd

 

[bj40green]

FYI: the 10 digit number is the original BOSCH part number used for production and ware house purposes.
The GPT xxx number is the commercial name. This GPT number refers always back to the 10 digit number.

Rudi