Maybe a Tach sensor?

[7.3_IDI_guy]

I now have a 93 7.3 with an E4OD and you have to shift the trans manualy for it to work right. If you put it in OD then it tries to take off in 3rd. But if you put it all the way down in 1st and manually shift up to OD then it does fine. It has a nice smooth shift to it. Could this be a tach sensor? my tach at idle is at zero and i know if the E4OD doesnt have an accurate reading from the tach then it will not shift properly. Now I know this is most likely part of the problem but is it ALL of the problem? Any help is greatly appreciated

 

[icanfixall]

Thanks for posting this.. Yes, the E4OD needs several signals to operate properly. The tach is one of them. Try removing it and cleaning of the magnetic pickup. they get dirty and stop working sometimes. You also need the injection pump tps switch properly calibrated to .96 to 1.2 volts at idle engine off settings. Warm up the engine and make the needed adjustments to get the reading you want. Off the end of the speedo cable at the trans is a signal generater that tells the trans how fast its going. The computer needs to see that too. All the computer does is tell the trans how to operate. Nothing more. Its found behind the drivers side foot well panel way back behind the parking brake.... A realy tuff location to get too...

 

[DragRag]

Your tach sensor is bad for sure, and yes it will cause shifting problems for sure. Clean it up as said, and if that doesn't work, replace it. Operating under the conditions you are in can and will cause more damage so take care of it ASAP.

 

[Dsl_Dog_Treat]

Replace the tach as said. If the tach even glitches, it's enough to put the trans into a snit.

 

[bab029]

Off the end of the speedo cable at the trans is a signal generater that tells the trans how fast its going. The computer needs to see that too.

His speed sensor should be on top of the rear axle.

 

[Kevin 007]

And all this info goes through the harness and a big plastic rectangulat plug on the passenger side of the transmission. If it is in bad shape or dirty or broken, the signals arn't getting through. And the tranny will do incredible things without the proper signals, what yours is doing is almost exactly what mine did with the broken, dirty and worn out harness and plug. I got a repair kit from ebay and it was the best $30 I spent on a truck, EVER!!!

 

[7.3_IDI_guy]

Well i drove it a little ways last night and when I get to about 50-55 it starts vibrating? Now I believe that the tach sensor will make the trans do some crazy stuff . But I need to repair the tach sensor and do a filter and fluid change and that will fix it I think, But one more question... How many quarts of trans fluid and what kind is recommended?