86suburbanNJ609
Full Access Member
- Joined
- Feb 25, 2018
- Posts
- 167
- Reaction score
- 66
- Location
- South Jersey
- First Name
- Aaron
- Truck Year
- 1986
- Truck Model
- Suburban
- Engine Size
- 383
When I got the the truck I noticed in overdrive when downshifting it stays in high gear until about 25mph and she'll shift herself. I started down shifting manually into drive and then putting it back into overdrive when over 50.I recently replaced the manual fuel pump on the truck and noticed that now going through the gears it wants to shift from 3rd to OD very rapidly around 35mph. My gut is telling me that it's a vacuum problem but I'm not sure. Any help would be appreciated thanks.