Checking the sensors on the Y Pipe and Waterpump

[Azar]

Hello,

As a part of engine rebuilt I am checking everything and replacing worn parts.

There are 3 sensors on the Y Pipe and water pump plus vacuum switch. What is the best way testing them to make sure they work?

The photos of 40 year old pump and parts are attached just FYI.

Thank you!https://uploads.tapatalk-cdn.com/20210521/a9dc75b6a4d7d01aefa9aea464902cf2.jpghttps://uploads.tapatalk-cdn.com/20210521/d17e30eb42db731785fe00825e73cb0d.jpghttps://uploads.tapatalk-cdn.com/20210521/430a6c28bf7218fc99a2d02047585ba4.jpghttps://uploads.tapatalk-cdn.com/20210521/15ce6c708090b97b03a7174d412ae1ec.jpghttps://uploads.tapatalk-cdn.com/20210521/1e81840604ae2509c9bfe32e31ae0aca.jpghttps://uploads.tapatalk-cdn.com/20210521/eb1624f3c6db4e93db026554160cd935.jpghttps://uploads.tapatalk-cdn.com/20210521/4dc4dca76755d2cff0455209faf62760.jpghttps://uploads.tapatalk-cdn.com/20210521/0ebd44b9a8b13cb0693f95499f15d7e4.jpghttps://uploads.tapatalk-cdn.com/20210521/854078f93eccd4d4b5a098648eb07941.jpg

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[Azar]

Also, in the coolant hoses set from DMCH , which I brought before shipping my car over, there is one sensor. I don't have access to the car now, anyone knows which sensor is that? Appreciate your help.

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[Ron]

Also, in the coolant hoses set from DMCH , which I brought before shipping my car over, there is one sensor. I don't have access to the car now, anyone knows which sensor is that? Appreciate your help.

Gesendet von meinem Mi 9T mit TapatalkThe set lists "100816 Switch, Cooling Fan" (AKA Otterstat).
See #65 HERE...same part number. (https://store.delorean.com/parts/engine/1-3-2-piping-to-waterpump.html)

[Azar]

The set lists "100816 Switch, Cooling Fan" (AKA Otterstat).
See #65 HERE...same part number. (https://store.delorean.com/parts/engine/1-3-2-piping-to-waterpump.html)Thanks Ron! So will replace it.

As for the other sensors, I did not really have problems with the engine running, except fluctuating idle when cold, so I presume those sensors are fine.

(Well apart from the low oil pressure, the reason why we are rebuilding motor).

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[Ron]

Thanks Ron! So will replace it.

As for the other sensors, I did not really have problems with the engine running, except fluctuating idle when cold, so I presume those sensors are fine.

(Well apart from the low oil pressure, the reason why we are rebuilding motor).You're welcome.

=====

Since no one has answered your original question yet, I'll take a stab at it.
The words used to name and describe the three are intermixed/different in the same/different document(s). So I'll put it this way. (Two of them can affect the idle, so I'd do it while I was in there, or get new ones.) To check them all, you'd need a ohm meter, vacuum source, water and a way to measure and control its temperature.

Basically:
If you connect vacuum to the center port of the vacuum switch:
Vacuum should switch between top/bottom port as it passes (104°F).

For the switch with a single male blade terminal:
The switch should be closed (connecting the male terminal to its base) at 15 ± 3°C (59°F) and lower.

For the switch with two female terminals:
The switch should make/break a connection between its two terminals as it passes 15°C (59°F).
EDIT: See post 8 below!

[Azar]

You're welcome.

=====

Since no one has answered your original question yet, I'll take a stab at it.
The words used to name and describe the three are intermixed/different in the same/different document(s). So I'll put it this way. (Two of them can affect the idle, so I'd do it while I was in there, or get new ones.) To check them all, you'd need a ohm meter, vacuum source, water and a way to measure and control its temperature.

Basically:
If you connect vacuum to the center port of the vacuum switch:
Vacuum should switch between top/bottom port as it passes (104°F).

For the switch with a single male blade terminal:
The switch should be closed (connecting the male terminal to its base) at 15 ± 3°C (59°F) and lower.

For the switch with two female terminals:
The switch should make/break a connection between its two terminals as it passes 15°C (59°F).As usual, many thanks Ron! The switches are not really cheap so I will need to decide if I can test them or just order new...
I start to think that ordering new or buying used engine would be a better way after replacing almost everything in the old engine :)

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[Bitsyncmaster]

I've only been in my valley one time but I know the idle ECU uses a variable resistance that changes with coolant temp. So I guess that one is the two terminal shown on the schematic as the IDLE SPEED REG SW. I think the one terminal switch is the THERMAL THROTTLE ENRICHMENT which feeds the lambda ECU and is in parallel with the THROTTLE ENRICHMENT MICO SW.

[Ron]

I've only been in my valley one time but I know the idle ECU uses a variable resistance that changes with coolant temp. So I guess that one is the two terminal shown on the schematic as the IDLE SPEED REG SW.I've seen them broken, but not bad otherwise.
Short story: You're right!
Without a quick/easy way to test it properly, I still wanted to know what was going on. So I got one out of my bones box, set the shower to 100°F (37.7°C) and it measured 1.3KΩ and increased as the temp fell.

Long version:
I see "Idle Speed Reg Sw" on a schematic I got from you (iirc). It shows a make break switch. I have several others which show a resistor in the symbol, but then they all use that same symbol and name for the "THERMAL THROTTLE ENRICHMENT", which I'm sure makes/brakes to the case (ground). I was going by the WSM schematic since most of us have one. It calls the two prong one "152. IDLESPEED REGULATOR MICRO SWITCH"....and has the same name for "151. IDLESPEED REGULATOR MICRO SWITCH" -- As I mentioned before, documentation SUX.
(Eric's schematic is the only one that names it correctly, imo, "Thermistor".)

Thanks, good catch!

[Azar]

You're welcome.

=====

Since no one has answered your original question yet, I'll take a stab at it.
The words used to name and describe the three are intermixed/different in the same/different document(s). So I'll put it this way. (Two of them can affect the idle, so I'd do it while I was in there, or get new ones.) To check them all, you'd need a ohm meter, vacuum source, water and a way to measure and control its temperature.

Basically:
If you connect vacuum to the center port of the vacuum switch:
Vacuum should switch between top/bottom port as it passes (104°F).

For the switch with a single male blade terminal:
The switch should be closed (connecting the male terminal to its base) at 15 ± 3°C (59°F) and lower.


Hi Ron,
I tried and got different readings...
I don't have the vacuum so tried to blow through the center port. At room temeperature the air was coming out of upper port. I put it to the 120F water and it did not switch. Is it stuck in one position?

For the switch with a single male blade terminal (Lambda):
At room temperature it iwas open (about 18C here with the open window) - but still had 200kOhm at 120F, gradually increasing with temperature going down...

[Azar]

I've seen them broken, but not bad otherwise.
Short story: You're right!
Without a quick/easy way to test it properly, I still wanted to know what was going on. So I got one out of my bones box, set the shower to 100°F (37.7°C) and it measured 1.3KΩ and increased as the temp fell.


again, different readings. at room temperature it was 10kOhm and at 120F it was 4kOhm graudally increasing as temp fall.
Perhaps all of them are faulty :(

[Azar]

And what about the Thermotime switch on the pump housing https://store.delorean.com/parts/engine/1-3-0-water-pump.html number 24? It is showing 30Ohm at room temperature and at 90F

[Ron]

Hi Ron,
I tried and got different readings...
I don't have the vacuum so tried to blow through the center port. At room temeperature the air was coming out of upper port. I put it to the 120F water and it did not switch. Is it stuck in one position?I'd say so, assuming you gave it ample time to warm up.


For the switch with a single male blade terminal (Lambda):
At room temperature it iwas open (about 18C here with the open window) - but still had 200kOhm at 120F, gradually increasing with temperature going down...18 C is (too) close to the switching point. Maybe try again with ice water...
Increasing (or decreasing) readings don't make sense to me.
It should be closed, grounding the lambda terminal #7, when it is cold (12 C or less), where you should read zero resistance.
It should be open when it is warm (18 C or greater), where you should read infinite resistance.


To be exact, at D:04:15 the manual says:
[I]2. Thermal SwitchContact shall open at 15 ± 3°C (59°F)
Close at max. of 5°C below its opening temperature

======

(RE: The 2 prong)

again, different readings. at room temperature it was 10kOhm and at 120F it was 4kOhm graudally increasing as temp fall.
Perhaps all of them are faulty :(It would be be very odd if they were.

I didn't have a way to check except at 100F and it was cheesy. (I just wanted to know if it varied and which way WRT temp.) Not to mention the one I have is an unproven pull-off from a core engine... I can see where yours would cool off and possibly match what I got at 100F....

I'd order the vacuum valve and ask the vendor about this... (I'd ask Mike at DMCMW.)

[Ron]

And what about the Thermotime switch on the pump housing https://store.delorean.com/parts/engine/1-3-0-water-pump.html number 24? It is showing 30Ohm at room temperature and at 90FIt is more complicated to test... You'd have to test from prong to prong, from each of the two to the case, at different temps...and repeat some of that again after applying power to one prong (get it wrong and it's toast)....

I'd just wait and see if the cold start valve is operating correctly since it isn't buried.

[Azar]

I'd say so, assuming you gave it ample time to warm up.

18 C is (too) close to the switching point. Maybe try again with ice water...
Increasing (or decreasing) readings don't make sense to me.
It should be closed, grounding the lambda terminal #7, when it is cold (12 C or less), where you should read zero resistance.
It should be open when it is warm (18 C or greater), where you should read infinite resistance.


To be exact, at D:04:15 the manual says:
[I]2. Thermal SwitchContact shall open at 15 ± 3°C (59°F)
Close at max. of 5°C below its opening temperature

======

(RE: The 2 prong)
It would be be very odd if they were.

I didn't have a way to check except at 100F and it was cheesy. (I just wanted to know if it varied and which way WRT temp.) Not to mention the one I have is an unproven pull-off from a core engine... I can see where yours would cool off and possibly match what I got at 100F....

I'd order the vacuum valve and ask the vendor about this... (I'd ask Mike at DMCMW.)

Thanks Ron, so I have put lambda Switch to the fridge and it reads zero now. it looks like only the vacuum switch is not "switching".

[Azar]

I have heated up the vacuum switch higher than 120F and it switched! I have measured the temp as it cooled down and it switched back at around 119F (48°C).
Now back assembling the motor!

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[Azar]

It is more complicated to test... You'd have to test from prong to prong, from each of the two to the case, at different temps...and repeat some of that again after applying power to one prong (get it wrong and it's toast)....

I'd just wait and see if the cold start valve is operating correctly since it isn't buried.

Ron, I tried to test the Thermo-Time switch which suppose to open at 35C. I did not apply the current. At room temp (25C) the heating circuit is reading 30 Ohm. The other one (which sends current to the cold start valve) is closed. When I put it to 45C water the heating circuit reads 60 Ohm and the cold start valve circuit jumped to 120 Ohm after 2 minutes and stayed there. DMC says it should be infinite? https://support.delorean.com/kb/a60/cold-start-issues.aspx
I hope it is enough not to operate the cold start valve? Once we start the car after assembly, How can i be sure that the cold start valve is not spraying open all the time? This was one of the concerns before we disassembled the engine - it was running very rich.

The other mistery is the Idle Speed Reg Sw, which as per DMC workshop manual has to switch at 15C but in fact - yours is reading 1,3kOhm at 100F and increasing, mine is reading about 4 times higher resistance at the same temp and increasing...

[Ron]

Ron, I tried to test the Thermo-Time switch which suppose to open at 35C. I did not apply the current. At room temp (25C) the heating circuit is reading 30 Ohm. The other one (which sends current to the cold start valve) is closed. When I put it to 45C water the heating circuit reads 60 Ohm and the cold start valve circuit jumped to 120 Ohm after 2 minutes and stayed there. DMC says it should be infinite? https://support.delorean.com/kb/a60/cold-start-issues.aspx
I hope it is enough not to operate the cold start valve? Once we start the car after assembly, How can i be sure that the cold start valve is not spraying open all the time? This was one of the concerns before we disassembled the engine - it was running very rich.

The other mistery is the Idle Speed Reg Sw, which as per DMC workshop manual has to switch at 15C but in fact - yours is reading 1,3kOhm at 100F and increasing, mine is reading about 4 times higher resistance at the same temp and increasing...Actually, "the other one" doesn't send power to the the cold start valve (CSV). It grounds power from the CSV, when it is below 35C.
Also, if you have your meter set to (Rx1) as in the article, 120 ohms would read as infinite (out of range...depending on the meter). According to the drawing in the WSM at D:01:01, it should never be infinite because one of the two heating elements always connects it to ground....

I would find a suitable container to catch fuel in, remove the CSV, and see that while cranking, it sprays when the unit is below ~35C and does not spray when above ~35C (or after ~30 seconds of total cranking time). You can disconnect the White with Yellow stripe wire at the ignition resistors to keep the engine from starting during the tests.

[Azar]

Actually, "the other one" doesn't send power to the the cold start valve (CSV). It grounds power from the CSV, when it is below 35C.
Also, if you have your meter set to (Rx1) as in the article, 120 ohms would read as infinite (out of range...depending on the meter). According to the drawing in the WSM at D:01:01, it should never be infinite because one of the two heating elements always connects it to ground....

I would find a suitable container to catch fuel in, remove the CSV, and see that while cranking, it sprays when the unit is below ~35C and does not spray when above ~35C (or after ~30 seconds of total cranking time). You can disconnect the White with Yellow stripe wire at the ignition resistors to keep the engine from starting during the tests.Thanks Ron, sure, it provides the ground to the CSV.
My multimeter doesn't have RX1 or such.
Just realised that the whole circuit only active while cranking. So no way to have the CSV spraying after engine running. I am happy with my TTS. Thanks again for your help!

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[Ron]

:thumbup: