I have a 96 F250 Supercab with a 5.8L (351W) engine and an E4OD transmission. It is a 4WD with manual locking hubs. I am experiencing power problems in 2nd gear. When driving and the truck shifts through the gears the truck falls flat on its face (looses power) when it gets to the second gear range. When it does this the engine starts to knock and ping. It seems as though I have two options, get off the accelerator or take it out of overdrive mode and hit the accelerator hard and try to get it to kick down to get by the 2nd gear range. We do plow with this truck, and while the general thought is that you plow in 2nd gear with the Overdrive Off, this truck doesn't seem to have the power to move in 2nd gear. If I am on the highway with the overdrive on, I have to take the overdrive off to get it to get by the problem spot so that I can keep up to speed. Is there any type of module or anything that could cause this problem. The rpm's don't seem to race in the 2nd gear range which leads me to think the transmission is not slipping. There does seem to be a small miss in the engine when I am at idle, but the wires, plugs, distributor cap and rotor were just replaced less than 1,000 miles ago. There is a hole in the catalytic converter but it isn't major. I don't think that would cause the problem, but it seemed to start doing this around the same time the cat started leaking. Any suggestions or help someone can offer will be greatly appreciated. Thanks very much

 

You need to do 2 things, check fuel pressure and pull codes, if nothing else that will eliminate a lot of possibilities. This leak in the exhaust is it before the O2 sensor or near it? If so this will cause a lean condition that will hurt power.

 

"general thought you plow in 2nd gear with overdrive off"

Why do you think this. Do you physically have the shifter in 2nd gear...
That puts a lot of strain on the trans. Honestly when your truck is underpowered or you plow a lot, I reccomend low range and leave it in drive with OD off. Let it shift. You could have overheated the trans and hurt it.

Pull codes. The trans is very computer controlled.

Check timing. The efi 351 in my experience is touchy with how much base timing. I can only run 10-11 in my 3. Check base timing and adjust to 10 for now. Check fuel pressure. Run a can of sea foam in each tank of gas and replace fuel filter.

Your description is basically saying every gear there's a problem. On hyway you're not in 2nd gear and to get it into 2nd on hyway you gotta really beat on it. We need a better description of the problem please.

 

The leak is after the O2 sensor, as the leak is in the cat itself, and the O2 on this vehicle is located before the cat where the y pipe comes together before going into the cat.

I will check the codes, but there has been no engine lights or anything coming on. But I guess it can still throw codes.

I bought this truck back in Aug. I have only used it to plow so we have less than 1000 miles on it in that time. We replaced the fuel filter when we got the truck, I put sea foam in both tanks at that time, and we replaced the plugs, wires, distributor cap, and rotor at that time as well.

We plow in 2nd gear because I was told this is best for the transmission, and we aren't doing roads where it would shift much above 2nd gear most of the time and you generally are only going 15-20 mph until the end when you are only pushing slush. We do shorter residential roads so we are backing up a lot and not doing just straight forward pushing. I guess that is why we push in 2nd gear. I know the OD has to be off or you will burn that up, but outside of that it is just what I was taught and have always done.

I wish I could give a better description, but I am not sure I can add a lot more at this time. I will run it again and see if I can get a better more exact description of what is happening.

thanks

 

If you're only in 2nd gear, pushing the od off button does nothing. The od off button only has an effect on the transmission when it's actually in overdrive.

You need to count your shifts again and get back to us. It seems there is a slight discrepancy in your example of how it shifts. Is it underpowered going up through the gears or is it underpowered on hyway.

 

Yes, it can. As UNTAMND said, your trans is controlled quite a bit by the computer, so pull the codes as soon as you can.