I have a 91 econoline e250 with the 351 and e4od behind it. I blew the front seal and didn't get off the road soon enough before I burnt up that transmission. I swapped a junkyard transmission in and now I have all kinds of issues.

The torque converter feels as if it locking and unlocking while cruising around 45-50 mph. This seems to be caused by brake light issues, so I verified that my brake lights work and cleaned the brake light switch. That actually helped alot, so I think I just need a new switch as cleaning the old one helped but didn't eliminate the issue. Am I on the right track here?

The transmission does not downshift like I think it should. I can put my foot on the floor and it'll just chug up a hill instead of downshifting like it should. There are also times when it hunts for gears and goes in and out of 2nd and 3rd or 3rd and 4th.

The transmission does not like to start off in D. It does just fine in 1st and 2nd though. I can then shift into drive and everything operates fine. This only happens if I come to a complete stop. Occasionally it will start off in drive like it is completely fine though.

The motor bogs when it shifts from 2nd to 3rd. Not sure about this either. If I am accelerating slowly this isn't much of an issue, but it still bogs.

I have replaced the mlps, the vss on the rear differential, and the tps sensor. I also replaced the relay for the transmission as I was only getting 5v at the solenoid connector plug. I tried to Google a schematic on what the voltage should be and saw a random forum posting that said it needed to be 12v. That fixed my freewheeling when shifting to 3rd issue. I still get an IAT, EGR, and HO2S codes, but it is my understanding that none of those circuits affect the transmission. Might be wrong. I don't want to put much more money into this old van, so a rebuild isn't an option right now. I'd be happy if it'd downshift normally and the tq wouldn't act up.

It's frustrating as I swapped a lot of stuff into the van and nothing has worked. Some things have definitely helped, but I'm still happy.

Any help would be greatly appreciated. Thanks.

 

Are there any codes stored?

 

I'll double check tomorrow as I didn't get time to check tonight. I tried to reset the computer by leaving the battery disconnected before the last time I drove it, so hopefully that doesn't affect anything.

 

Don't bother looking for codes. If they were there disconnecting the battery cleared them.

Drive it some more and see if it happens again. Then read the codes without disconnecting the battery.

 

Ok just pulled the koeo codes. 67, 33, 41. The ac was removed from this old pig, so that should explain 67. 33 is egr valve, but all the emissions stuff was also removed or disabled. 41 is HO2S. I'm sure that old sensor is shot as well, but how would that affect the transmission?

 

Did you drive it long enough for the problem to occur before pulling the codes?

 

Yes I did. That is what scares me as I don't get any codes that point to the transmission.

 

Engine problems can affect the transmission. Get all the engine codes taken care of. That often fixes the transmission.

 

That's not what I hoped to hear, but I expected that. I'll start buying parts I guess. Thanks.