89 F250 6mpg
09-16-2012, 09:20 AM
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89 F250 6mpg
Ok so I have an 89 F250 hd with a 351w e4od and 3.55 gears. On my last 3 refuel I have calculated 6-7 mpg. now at 50mph my rpm is around 2500 this seems really high to me. Also my overdrive switch is a choke cable(like that when I bought it) and there is a connector hanging off the transmission. Could this be the torque converter failing to lock up? Any help is much appreciated.
09-16-2012, 10:32 AM
Join Date: Jul 2007
Location: Rhode Island
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Are you saying you have a carb? 50MPH should be ~1300-1500 RPM with 3.55s and an E4OD.
09-16-2012, 10:50 AM
Join Date: Oct 2011
Location: Pueblo, CO
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My truck doesn't have OD and with 3.55 gears and a 460 it does about 2500 at 55mph. I think your truck isn't going into OD.
09-16-2012, 11:02 AM
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Location: Gilbert, PA
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And 6mpg is still TERRIBLE even without OD
09-16-2012, 11:19 AM
Join Date: Mar 2011
Location: Central Wisconsin
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Yeah my truck doesn't have OD with the same motor and gears and its jacked up with bigger tires and I can pull 8mpg all day.
09-16-2012, 01:35 PM
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The truck is fuel injection and it shifts through all 4 gears but something is defiantly wrong
09-16-2012, 01:38 PM
Join Date: Oct 2011
Location: Pueblo, CO
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Did you try pulling the codes? The ECM controls the engine and the trans so it may provide some insight.
09-16-2012, 01:43 PM
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I have not pulled codes yet as I don't have a code reader. I forgot to mention all of my emissions equipment is rusted off.
09-16-2012, 01:44 PM
Join Date: Oct 2011
Location: Pueblo, CO
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Don't need a code reader. There's a way to do it with just a piece of wire or a paper clip. I found a good youtube video of it a while back.
09-16-2012, 01:47 PM
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Interesting I will look that up but does anyone know what might be causing the high rpm?
09-16-2012, 04:01 PM
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You may be feeling the torque converter locking instead of it actually shifting. What's the gearing in the truck? Also, you might want to find out what that unplugged connector is for...
09-16-2012, 04:08 PM
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It has 3.55 gears and I think the connector is for the od and tc lockup. would the rpm be that high without lockup?
09-16-2012, 10:28 PM
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If it's EFI, what in the world is your "Choke" cable connected to?
The E4OD has only two electrical connectors. One is on the passenger side and plugs directly into the transmission, the other one goes into the range position switch which is on the drivers side where the shift cable hooks up.
09-16-2012, 10:40 PM
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The choke cable engages overdrive. The truck was a 5 speed and the guy I bought it from swapped an automatic into it. I only see one connector on the drivers side. Maybe not e4od?
09-16-2012, 10:46 PM
Join Date: Oct 2011
Location: Pueblo, CO
Posts: 1,179
The E4OD is electronically controlled so I'm pretty sure there's no way to rig a cable to engage the OD on it. Maybe you have an auxiliary OD unit behind a C6. You need to crawl under there and figure out exactly what you have.
