Fault 26 on HFM/SFI OBD1 is Upshift Delay fault.
The shift delay is from 2nd to 3rd gear when cold for cat warm up.
Thwe most common fault is the vac element at the trans cable end. The test is
to pull a hand vac at the hose going to the element to see if it holds vac.
This is the green vac hose coming out of the switch over valve just behind the