924Board.org

[copeina]

Working back to front on my 78 924 NA and finally spending some time under the hood. Got the ignition all resolved, and got it started for the first time the other night. The fuel gauge and tach even work. Woot!

Along the way, I've found a quirk with the air flow sensor on the side of the air flow meter. I understand these were only on early models and have some relationship with the fuel pump electrical shut off.

With mine, (I've got a 5 pin fuel relay so the pump runs whenever ignition is on), with the air flow plunger in the resting position, the fuel pump works as expected. Manually lifting the plunger immediately shuts off the pump. Return it to the resting position and the pump runs again, so there is obviously a switch of some type in there. Unplugging the sensor turns off the pump. (Anything I've read says the pump should run when that is unplugged) Jumping the pins returns the pump to running and is no longer affected by the plunger position for obvious reasons.

Long question short, what exactly is that thing, and any idea why is it behaving the opposite of expected?

Thank you for any insights. Right now, I'm leaning towards adding it to the "things to delete" list.

/Kris
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1978 924 NA Project

[!tom]

https://www.924board.org/viewtopic.php?p=289747
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78 924 NA
5-lug

[copeina]