Ok my Expy is 98 with 4.6 with 180,000 When I bought it the back passenger cylinder was missing. I replaced coils (this is not the ones with one per plug setup) wires and plugs and it ran like a champ. I recently took it on its first extended trip. I pulled a trailer (small open one) 400 miles to my parents (truck ran fine, but got about 13-14 MPG! at 75) I then loaded the trailer with a Snowblower/riding lawnmower/push mower and a few smaller things (paint cans for some house painting, etc) and filled the back with some end tables and such.. not a HUGE load, but a load. First 100 miles at 65, smooth. but at about 100 miles into the return trip I noticed i had no power.. thing ws kicking into 2nd gear on hills and doing 4500RPM.. and still having issues. I first i was not sure waht was up. i thouhgt maybe i broke a motor mount as the vibration was bad.. but when i stopped and was out of gear and it was till bad i knew i had a miss. I pulled over and messed around with wires to make sure all where good and connected.. no help.. well as I had 300 miles to go. i just headed on.. tough run the next 100 miles was hilly and the old 4.6 was struggling. That 4600RPM stuff seemda bit excessive so I managed the footfeet up hills and never let it shift to 2nd unless I was going slower.. it did have no issue keeping 65MPH on the level.. after 100 miles I pulled in for gas ( was drinking it) again, poped hood and messed with wires.. no help.. so shut it off and took a bathroom break and grabbed a pop. came out and fired it up ( less then 5 minutes) and it was running fine.
here is the realy wierd part.. the trip to the parents I was getting about 13-14MPG (empty trailer and turck), the trip back to my home.. up to this point was about 12 (With the miss and a bigger load its expceted) now the last 200 miles it ran fine.. 75mph full load on trailer and in tuck and it appears i got about 17ish...
What im wondering .. why would it miss then when shut off and restarted not miss.. as a backyard mechanic I cant think of any reason expcet a lose wire to the coil ( which i have double checked) maybe failing coil? and why did my milage seem to increase all the sudden? I supect its tied toghter, but for the life of me i cant figure out how.. or maybe jut all in my head (has happened before)..
thought i would fish for some thoughts.
here is the realy wierd part.. the trip to the parents I was getting about 13-14MPG (empty trailer and turck), the trip back to my home.. up to this point was about 12 (With the miss and a bigger load its expceted) now the last 200 miles it ran fine.. 75mph full load on trailer and in tuck and it appears i got about 17ish...
What im wondering .. why would it miss then when shut off and restarted not miss.. as a backyard mechanic I cant think of any reason expcet a lose wire to the coil ( which i have double checked) maybe failing coil? and why did my milage seem to increase all the sudden? I supect its tied toghter, but for the life of me i cant figure out how.. or maybe jut all in my head (has happened before)..
thought i would fish for some thoughts.
