Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

crankshaft reading odd while cranking

More
4 years 8 months ago #33040 by Carstuff
crankshaft reading odd while cranking was created by Carstuff
How could a crankshaft reading be erratic while cranking but good while running?

in the video is a slow down zoomed in of the crankshaft sensor during cranking.
signal begans 10 seconds in.

Please Log in or Create an account to join the conversation.

More
4 years 8 months ago - 4 years 8 months ago #33041 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic crankshaft reading odd while cranking
Depends on the manufacturer and engine model type but a lot of engines will run quite happily on the cam sensor alone --- with others it is the otherway around. Usual clue is a slightly extended cranking time.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 4 years 8 months ago by Andy.MacFadyen.

Please Log in or Create an account to join the conversation.

More
4 years 8 months ago #33052 by Carstuff
Replied by Carstuff on topic crankshaft reading odd while cranking
The wave form while running is ok when comparing it to the snapon image. Its only during cranking its like the second hump is erratic during cranking

Please Log in or Create an account to join the conversation.

More
4 years 8 months ago #33064 by Chad
Replied by Chad on topic crankshaft reading odd while cranking
Variable Reluctance Sensors produce an AC sine wave. The amplitude of the signal is affected by different factors. Rotational speed being one of them. The faster the reluctor wheel turns, the higher the amplitude will be. The Air gap between the sensor and reluctor is another factor that will affect amplitude.
"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."
I have learned more by being wrong, than I have by being right. :-)

Please Log in or Create an account to join the conversation.

More
4 years 8 months ago #33066 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic crankshaft reading odd while cranking
With magneto resistive crank sensors the engine computer looks at the signal with the DC filtered out, so once you intially connect up the scope and get a first look switch the scope to AC and you will get a cleaner easier to read trace on the scope.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)

Please Log in or Create an account to join the conversation.

Time to create page: 0.186 seconds