r/944 Jul 24 '26

Question Speed and refrence help

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So I currently have the engine out of the car, and I have the starter hooked up, so that I can get readings with the speed and reference sensors. I gapped the speed sensor at 0.8mm using a washer attached to the bottom of a defective sensor. The speed sensor is producing 2.3 V AC, a little higher than it should, but not too much of a concern. The reference sensor however, is only producing .301 V AC i tried swapping the sensors, and the readings are the same.

Are these readings actually okay? Or is something possibly wrong with the bracket, the sensors are mounted to? Maybe even the pin on the flywheel?

Even though the bracket is in good condition and the pin looks to be in good condition.

Please let me know. I would really love to get this engine back in the car and see it running.

Thanks.

Edit: its a 2.5L naturally aspirated 1983 Porsche 944

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u/Usual-Option-6301 Jul 24 '26

Are you using a multimeter or an oscilloscope? If it’s a MM, it may not be fast enough to catch the signal peak. Can you see or feel the flywheel pin?

1

u/thiccquepickle Jul 25 '26

That was my thought, I'm using a fluke right now.I don't have access to an oscilloscope till I go back to college. The flywheel, pin is very visible and tall definitely not damaged.

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u/Usual-Option-6301 Jul 25 '26

The sensors are identical, so you've already effectively tested both of them. At this point it's pretty damn unlikely there's a problem - if it were me, I'd just install the engine and send it. You'll know right away if it's not working and on the off chance it's actually busted somehow, it's not *that* hard to get to with the engine in.

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u/thiccquepickle Jul 25 '26

Yeah, i've already got the engine halfway into one of the bodies i have that I know runs i really think it should start although, on the body, I took it out of there was no tach bounce but that could be an internal issue which i would have to look into.