my 90 f150 E4OD / 4.9, stalls sometimes when i put it in reverse. had the tranny rebuilt a month or so ago, but did it before then. i replaced the iac and that helped starting when cold but still does this reverse stalling, not all the time but at least once a day.

 

A few things come to mind: 1) Trans filter fell into the trans pan. 2) TPS might be out of spec (should be below 1v when the throttle is closed) and 3) MLPS is bad.

 

remember reading a lot about the MLPS being bad in a lot of these trucks. as for the TPS, seems easy enough to test.

 

Consider bad torque converter. Had many in our E series ambulances drive fine but die when shifted into reverse. Remedy has always been a new torque converter. Ford is notorious about torque lock up when shifting into reverse.

 

well the transmission is rebuilt, with new torque convertor, about a month ago. funny thing is it didnt do it for a couple weeks after rebuilt was put in.

 

Could be a bad converter. Kind of coincidence that you just replaced it and getting the symptoms.

 

Yea, not everyone builds high quality torque converters.

 

how do i tell if it the convertor.

 

Check codes. If no codes, take it back to the shop or pull the converter and replace it. No testing.....sorry.

 

the only worry about the shop is of course there going to say its something else, and once they fix that and it still does it they will say ok but what we fixed still needed to be fixed. kinda sad where i live, your better off buying a new truck instead of trying to get your old one fixed.