If it wont go faster than 20 MPH, sounds like you have some real issues with the transmission or a severely fouled up fuel system...Better get that truck looked at ASAP!
Did this answer help in ANY way @ omero??
yes. thank u. it was the fuel pump.
Looking for a Used F-150 in your area?
CarGurus has 207,475 nationwide F-150 listings starting at $1,200.
Search Ford F-150 Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford F-150 Experts