...but so many do run for a second, it's become expected. I saw a post recently that said the "pre-run" happens when the engine stops with the distributor Hall Sensor positioned "just so", and producing one pulse when the key is turned on. (Would that apply to your '75?)

I think this pre-run thing IS normal on later cars like my '93 940. But in my several years with K and LH-jet, I've *never* seen anything in Bosch and other manuals describing such a "feature".

Instead, they always describe the "Safety" features, like the contacts on the early Airflow Sensor, which won't let the relays pick unless the engine is sucking air (lifting the plate). Or in the later systems where Ignition pulses are required (i.e. don't pump fuel into a dead engine).

I had 2 cars that never pre-ran the pumps, then began doing it intermittently. I always assumed there was something wrong with the FI Relay and replaced it, which ended the pre-running till next time (I should mention that my relay stash is vintage Pick n Pull).

I'll believe the pre-run is a Bosch FI feature if someone can tell me where it is so defined. Personally, I think now that it's a good thing, but not part of the system design (on the older cars).

--
Bruce Young,
'93 940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and still here)
New 144 from '67 to '78
Used '62 122 from '63 to '67