help no shift

[93punow]

my 93 2500 2wd will not shift out of 2nd i replaced the heads lift pump dove for three days no problem then oil pressure dropped repalced ops now wont shift. checked grounds all hopefully. any ideas

[Kennedy]

I'd be looking at 2 things. Ignition switch and TPS. More than likely the TPS, but a lot miles/cycles on that old ignition switch.

Many a trans has been wasted due to faulty ignition switch and/or faulty/mis adjusted TPS.

[john8662]

Kennedy is right on the money.

TPS Article (http://www.thedieselpage.com/members/features/tps.htm)

Things have likely moved while removing heads, etc.

All you need is a Voltage meter (digital preferred) and get it in the range (be very precise though), Bad readings, or jumping around will indicate a bad TPS though. Many that are bad will go to max range on movement off idle (just a little), instead of varying throughout the percentage movement.

J