DeTomaso Mailing List: June 2000, Message #307

Charlie,

No, the shear pin shouldn't cause oil pressure to drop if the car still
runs. Yes, the cam drives the distributor, which drives the oil pump, BUT,
I would venture to say that if the shear pin went way south, you would
experience a consistently poor running condition, which it sounds like you
get varied... but then, figuring that the advance mechanism could
compensate a bit for this altered timing, could get it to run better at
higher RPM's.  What doesn't make sense is the running a few seconds,
dieing, then starting right up again..... with no popping or backfiring out
of the carb, which usually happens.

If the shear pin went big time, the car wouldn't run for beans, and you
wouldn't have any pressure....  but yours runs at higher r's... so ya
should have pressure.  The stammering would lean towards a roll pin... but
you should have pressure....  If the gear were spinning so much on the
shaft that it wasn't turning the oil pump, you'd think that the car
wouldn't run at all!!!

Windsors typically don't blow roll pins... but I guess it can happen.  Same
or similar design to a Cleveland....  I actually wonder why ya don't hear
about more 5L guys and 5.7L cars having this prob.....

Could be electrical. Oil guage is electric?  Engine is running funky....

I hope it's not deeper than a distributor!

Steve
"still running the original roll pin in my 351W"