Pico In Cylinder for the win

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Mitchroberson
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Joined: Mon May 09, 2022 1:09 pm

Pico In Cylinder for the win

Post by Mitchroberson »

I had purchased an old 1992 Ford F150 and it ran decent. So decided to do a tune up since wires looked rough. And plugs looked like they had not been changed in a while. So we pulled all the wires. Not paying much attention to fireing order. And we changed everything. Low and behold it would not start. Did all the basic tests. Spark, Manual compression, relative compression, Fuel, Air it all looked good. So after some thought I decided to do In cylinder compression test with cylinder 1 and put the spark plug wire to a spark tester with a secondary ignition pickup.
If you look closely you will notice spark is about 81 degrees from TDC. That is almost a cylinder off. So we reviewed our plug wire set up again. And confirmed it through 3 sources as well as multiple people saying we were right. when you looked at rotor it did not see to be in right position.
so to prove the point we moved the spark plug wires by 1 cylinder on the distributor cap. That is the second capture\screen shot you see. The truck started right up. So that tells me the original owner or his mechanic has messed with the distributor and it is off by a tooth or 2.
Would never have found it without the PICO and the Phad transducer.
Attachments
Ignition timing by moving spark plug wires by one..PNG
Spark timing in cylinder pressure transducer.PNG

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