choke operation explained?
10-10-11, 07:15 AM
#27
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So if you do this, when you pull the choke out, you'll energize the circuit, everything functions as normal but the #1 Water temp switch, now out of the circuit, will not break the circuit when it senses 158, so you'll have to push the choke in yourself, like any "manual choke" car. It seems as soon as you do push it back in, the whole circuit is shut down so the magnet won't be fighting to keep the **** out anymore. This seems better, if you run an artificial power source to the magnet, it will stay energized all time which might not make it very happy long term? I'll jump it as above, since new switches seem pricey not to mention the can of worms that will be opened trying to extract it from the pump housing.
10-10-11, 08:27 AM
#28
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Is this the dude in question?
autozone
What's a good RX7 specific vendor? (looking through vendor section here).
Can't help but wonder about pulling it and playing with it and possibly "fixing it". Anyone know the thread info so I can fit a plug while I play with it?
If you were really bored, I suppose you could rig up an adjustable temperarture probe, like what they use for radiator fan operation, set it to trip when you want but since this always close a circuit when a temp is reached, you'd have to wire in a relay such that it would ultimately open the circuit at higher temperatures, that would be complex.
What does the number 2 Water Temp Switch (the one in the radiator?) do? If it does the same thing can it be used to trip the choke circuit as well?
BTW the heat/ex warning light is constantly on so that is another (related?) issue. I was going to try to find the sensor under the passenger seat and disconnect it or jumper it, which ever shuts it up.
autozone
What's a good RX7 specific vendor? (looking through vendor section here).
Can't help but wonder about pulling it and playing with it and possibly "fixing it". Anyone know the thread info so I can fit a plug while I play with it?
If you were really bored, I suppose you could rig up an adjustable temperarture probe, like what they use for radiator fan operation, set it to trip when you want but since this always close a circuit when a temp is reached, you'd have to wire in a relay such that it would ultimately open the circuit at higher temperatures, that would be complex.
What does the number 2 Water Temp Switch (the one in the radiator?) do? If it does the same thing can it be used to trip the choke circuit as well?
BTW the heat/ex warning light is constantly on so that is another (related?) issue. I was going to try to find the sensor under the passenger seat and disconnect it or jumper it, which ever shuts it up.
Last edited by jvandyke; 10-10-11 at 08:47 AM.
10-10-11, 10:46 AM
#30
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Probably this one:
from autozone
Could get something like this (hopefully cheaper) Temp sensor
and you could take the feed from the ECU to #1 Water Temp Switch (LB wire) to the 30/87A side of a standard relay, hook the temp probe up to 86, ground 87 so when temp comes up, probe trips the relay shutting down the circuit (87 hooked to nothing).
from autozone
Could get something like this (hopefully cheaper) Temp sensor
and you could take the feed from the ECU to #1 Water Temp Switch (LB wire) to the 30/87A side of a standard relay, hook the temp probe up to 86, ground 87 so when temp comes up, probe trips the relay shutting down the circuit (87 hooked to nothing).
Last edited by jvandyke; 10-10-11 at 11:04 AM.
10-10-11, 12:20 PM
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That should read ground 85, 86 to temp probe. 30 is LB from ECU, disconnected from Temp Switch, 87a to LW wire (other side of temp switch, running to choke magnet) and 87 left unconnected.
Something like this. I'm not much of an electrickity guy though. I suppose you could hook 87 up to trigger some sort of light to tell you the probe has sensed temp, don't know why you'd need or want to know that though. Car cools off, rad cools off, probe resets itself, ready for cold start. Low side of above probe is 160, OEM was 158 in the coolant, 160 in rad fins is probably higher then 158 coolant. Could put probe in coolant stream (that's how I did it on my Midget, just bent into a hose connection, but leaks around it are annoying. Could ditch the engine fan since you've got the sensor anyway now! Run pure electric fan and save some HP for YOU.
Something like this. I'm not much of an electrickity guy though. I suppose you could hook 87 up to trigger some sort of light to tell you the probe has sensed temp, don't know why you'd need or want to know that though. Car cools off, rad cools off, probe resets itself, ready for cold start. Low side of above probe is 160, OEM was 158 in the coolant, 160 in rad fins is probably higher then 158 coolant. Could put probe in coolant stream (that's how I did it on my Midget, just bent into a hose connection, but leaks around it are annoying. Could ditch the engine fan since you've got the sensor anyway now! Run pure electric fan and save some HP for YOU.
Last edited by jvandyke; 10-10-11 at 12:26 PM.
10-10-11, 02:29 PM
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there probably is some other sensor that has the same thread and temp switch range, but maybe a different connector that could be a spade connector away from working and being cheaper
10-10-11, 07:23 PM
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I jumped the wires at the connector. I did nothing. So there must not be voltage coming from the ECU side. Will investigate further when we have a chance.
10-11-11, 07:38 AM
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key on, choke out (manually held out) no voltage on LB wire from ECU to #1 Water Temp Switch. So it could be the switch is fine after all and issues are further upstream. I just ran a hot to the LW wire to use the choke for last night's test drives. Worked great. Will check under dash at ECU and choke switch itself next. According to wiring schematic the Heat Hazard Sensor runs off this same wire from ECU and that idiot light is on with key and always on, related issue? I think I will hunt down that sensor (under passenger seat I believe) and disconnect, the OEM exhaust is long gone as is the cat so it is useless anyway. I have a vague memory that this heat sensor is normally closed, opens with heat, sends that info to ECU which sends signal to idiot light. So if there's no power coming out of terminal D of the ECU then it would trip the heat sensor and mess up the choke system, now I wonder about ECU's pin D and why it may not be outputting power there and how to test it..........will go a-search'n.
Last edited by jvandyke; 10-11-11 at 08:03 AM.
10-11-11, 12:47 PM
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I didn't do any of this (not that it isn't a good idea to ditch it). I inherited all this from POs. My son and I have owned this for about 10 days! I will look to see if there is even an ECU in the driver's footwell. Seems like the coils/igniter are (were) connected to it somehow. So you're running no ECU?
I'll stop working off conjecture and look for the ECU when I get home!
I'll stop working off conjecture and look for the ECU when I get home!
10-11-11, 08:53 PM
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No power on the LB at the #2 Water Temp Switch (radiator). ECU is there. Both leads fell off the #1 Water Temp Switch, I tested it, no continuity so it's open so I decided to run switched power through it to the choke magnet, soldered both harness leads back on the switch, ran switched power off coil to one side, then back to the LW wire from the other side. Key on, **** stays were put, test drive (joy ride really) choke **** receded on it's own. So switch is good. If I ever figure why there's no power to LB, I can easily reverse it.
10-11-11, 11:49 PM
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Wait, duh, full continuity on the switch so it was CLOSED meaning I knew power would flow through it to the choke magnet and only hoped it would OPEN when hot. It did. All is well, except I still wonder why no power coming through the LB wires out of the ECU.
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