@StarBear L Jetronic Temp Sensor II AFM |
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@StarBear L Jetronic Temp Sensor II AFM |
wonkipop |
Jun 5 2023, 03:12 PM
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#21
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Advanced Member Group: Members Posts: 4,372 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille |
@StarBear .
here is what i have on the Temp Sensor II inbuilt into the AFM on the 1.8 L Jetronic. i could be wrong but i don't think there is any effective way to test the air temp sensor in the AFM on our adam/eve in the garden of eden L Jetronic system. that sensor is not wired in separately. but maybe there is an expert here who knows. - in relation to the problem you are having with hot days and ultra high humidity causing the idle to drop to barely running - i'm not sure the symptom fits a faulty Temp Sensor II in the AFM. others here might know better. I would not have thought a faulty sensor would cause that dramatic a result. Temp Sensor 1 (CHT) - yes. but Temp Sensor II no. i am sure @Van B will pipe in with a more learned view. I would have thought Temp Sensor 2 fault would make the car run rich. I think that is how it would work. but again i am probably wrong. i'd have to think about it. most trouble shooting literature i can dig up says failure mode causes car to run richer generally. increased fuel consumption. |
StarBear |
Jun 6 2023, 12:47 PM
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#22
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Senior Member Group: Members Posts: 1,906 Joined: 2-September 09 From: NJ Member No.: 10,753 Region Association: North East States |
@Wonkipop
{- in relation to the problem you are having with hot days and ultra high humidity causing the idle to drop to barely running - i'm not sure the symptom fits a faulty Temp Sensor II in the AFM. others here might know better. I would not have thought a faulty sensor would cause that dramatic a result. Temp Sensor 1 (CHT) - yes. but Temp Sensor II no.} => That is my thought, but exploring it as don't know how sensitive it is. {i am sure @Van B will pipe in with a more learned view.} => Hope so! {I would have thought Temp Sensor 2 fault would make the car run rich.} => Depends on fault setting (if no signal temp goes to low fault or high fault)? I might think so - less dense air would call for less fuel, unless temp sensor out, then putting in too much fuel for the density/mass of air entering. If rich, would that drop the idle down? Seems to act at a critical temp point (OK for cold, cool and mildly warm outside air/humidity, then off the cliff with high, like 80+ deg F., 80% humidity, temp/humidity). Will start checking this out after this weekend's activities, then maybe start effort to install the NOS AFM, with adjusted CO, A/F sample port bung, etc. |
wonkipop |
Jun 6 2023, 04:48 PM
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#23
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Advanced Member Group: Members Posts: 4,372 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille |
@Wonkipop {- in relation to the problem you are having with hot days and ultra high humidity causing the idle to drop to barely running - i'm not sure the symptom fits a faulty Temp Sensor II in the AFM. others here might know better. I would not have thought a faulty sensor would cause that dramatic a result. Temp Sensor 1 (CHT) - yes. but Temp Sensor II no.} => That is my thought, but exploring it as don't know how sensitive it is. {i am sure @Van B will pipe in with a more learned view.} => Hope so! {I would have thought Temp Sensor 2 fault would make the car run rich.} => Depends on fault setting (if no signal temp goes to low fault or high fault)? I might think so - less dense air would call for less fuel, unless temp sensor out, then putting in too much fuel for the density/mass of air entering. If rich, would that drop the idle down? Seems to act at a critical temp point (OK for cold, cool and mildly warm outside air/humidity, then off the cliff with high, like 80+ deg F., 80% humidity, temp/humidity). Will start checking this out after this weekend's activities, then maybe start effort to install the NOS AFM, with adjusted CO, A/F sample port bung, etc. i think that is all you can do. replace AFM. see what happens. i don't believe there is any effective way to test the temp sensor on the 001 AFM. i guess there must be data somewhere on how to thoroughly test these earlier AFM units or otherwise the rebuilders would not be able to rebuild? i imagine if you access the interior of the AFM and were able to directly tap into the two wires from the temp sensor you could do it. i forget which pin it is that the temp sensor is fed into on ours, but its signal is mixed in with one of the other pins. interiors of AFMs are a place i do not go. (IMG:style_emoticons/default/biggrin.gif) @Van B laughs at me about that. (IMG:style_emoticons/default/biggrin.gif) i know that mike thinks the AFM on my 914 is a curiosity with the 6 pin connection. he'd never seen one. nothing that early ever came to australia originally. there is a guy who rebuilds AFM units. we got an AFM for a 964 fixed up by him. i should ask him about the ease of repairing/rebuilding mine. i'm betting he has never seen one with the 001 part no. in the flesh before. (IMG:style_emoticons/default/biggrin.gif) |
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