gm hei no spark?

Well either way on engine mounted. No spark out of engine. Has spark? Unit must be grounding somehow in the housing..... Starting with a new one Thursday. When it shows up.

The mag pickup gives a transient signal. As the distributor spins slower, the signal amplitude gets much weaker, eventually not triggering the ECU. The amplitude also depends on the reluctor gap. You can't see any of that without an O-scope. Best you can do w/ a multimeter is measure the pickup output in VAC mode (should be >1 VAC). Try to reproduce how fast the distributor will spin when cranking the engine. I would guesstimate cranking speed is >2 rev/sec (120 rpm), so 1 rev/sec for the distributor. Spin it by hand like that and verify spark. It might just be that your reluctor gap is too large or the engine is cranking too slowly. BTW, Chrysler later changed to Hall-effect pickups (even in later crank sensors), which are better since DC-accurate and give the same strong square-wave at all speeds.

ok I figured it out, the upper shaft bushing or bearing is too loose of a fit, caking too much side to o side play when installed and distributor shaft pushing up naturally against the oil pump drive gear. and going clockwise is causing the air relector gap too large and not causing spark, when spun by hand no force, will spark, can physically see the air gap play. never ran distributor, quality new junk these days.... I guess I should have checked it before install. will on the new one. even called summit, and tech there, said that the build quality in these are the issues... and im not crazy, suggested a different brand....

got new distributor today night and day difference in shaft play... I still had to reset air gap to .008" with brass feeler gauge. but this one should work! find out this weekend.

We love happy endings. Regardless, we always love it when the OP replies with the outcome. Great you figured it out - another "new ain't always better" result. BTW, the Mopar 1-finger pickup has never been robust. If you buy the Ningbo "ready-to-run" distributor (ebay) you will see the pickup has multiple fingers all the way around, which I expect averages out shaft wobble effect and also eliminates having to set a narrow gap. The later GM "small-cap" distributors have a similar pickup.