Tranny ?

['94IDITurbo7.3]

The vehicle is the one in my sig.
Last fall my OD light started flashing so i took it to the guy that rebuilt the tranny in my dads truck. He replaced the MLPS, didn't solve problem. then checked the TPS said it was way off, he reset it and then it was shifting nice and smooth around 2500-2700 rpm. drive it for a few days OD light comes back. he then replaced the tach sensor. that fixed it until the first of this year. then the OD light again i called him he said to check the tranny fluid. i did and it didn't even show on the dip stick. so i topped it off. Ever since christmas my shiftes 1-2-3-4 have been getting firmer and later around 3100-3200 rpm. i checked the TPS and it was right were he set it .8 idle - 3.8 WOT. tranny guy also checked and cleaned the elec plug on the pass side of tranny.
What could be causing my shift points to change like that?
also when i shift it into drive or reverse the engagement is delayed about 2 sec then it has a very firm engagement.

Thanks

 

[icanfixall]

First of all the low idle setting on the tps is wrong. Factory settings are .96 to 1.2 volts at the idle settings. The lower you have the voltage the softer the shifts will be. It might just be dirty electrical connections to the trans. We have 7 or 8 of them. Three are found just under the master cylinder. The others are on the trans. Both sides and the tail shaft have these connections. The main connecter is found on the passenger side of the trans behind a heat shield. Make sure you replace that shield when you clean the connection. Use electrical contact cleaner thats harmless to plastic. Let dry and grease with die-electrical grease. That will keep out the moisture and corrosion.

 

[trackspeeder]

Delayed reverse/drive engagement is a sticky boost valve.

 

['94IDITurbo7.3]

Delayed reverse/drive engagement is a sticky boost valve.

What is the boost valve and could that cause my upshifts to occur @ a higher rpm?

I had said the idle setting on my TPS was .8V.
That is wrong my idle setting is .99V. I don't know why i said it was .8V.

 

[trackspeeder]

The boost valve will effect drive and reverse engagement only. If it gets sticky it will delay this function. Usually you will get a hard engagement because the valve needs more pressure to overcome the problem.

To get to the boost valve, you must drop the entire valve body.

To adjust the up shifts play with the TPS a little more.

 

['94IDITurbo7.3]

i know there is something wrong w/ my trany b/c the TPS is right were my tranny guy set it and the shift points are changing w/o the TPS setting changing. anyways i can't lower the setting on the TPS enough to get my shifts were i want them without having the TPS idle setting out of range. im not going to change something that is fine to help another problem.

 

[Kevin 007]

Stock E40d's never seem to shift consistantly. At least, not for me.

 

[OLDBULL8]

'94IDITurbo7.3 Said:

i called him he said to check the tranny fluid. i did and it didn't even show on the dip stick. so i topped it off.

I would change the fluid before doing anything. As low as you said it was it could very well have run hot. Fluid level in the E4OD is somewhat critical for good operation. burnt fluid will make for sticky valves, very low level can sometimes damage the pump, and/or gum up the pump pressure regulator.

Below is what can happen from fluid level to low.

You must be registered for see images

You must be registered for see images

You must be registered for see images

 

['94IDITurbo7.3]

I was thninkng of changing the fluid anyways b/c after i got the truck it pretty much just sat around for about 6 months.
I don't have any tranny leaks. What could cause my fluid level to fall so much.

This is a total shot in the dark but could a partially stuck open thermostat effect tranny opperation b/c of the coolant not getting up to temp?

 

['94IDITurbo7.3]

I replaced my IP yesterday. when i put my TPS back on i set it to .99V idle, which is the same place it was w/ the old IP. Guess what now my truck shifts at about 2500-2700 rpm when i drive it civilized. when i really give it then it revs up to 3000rpm then shifts. the only thing now is my shifts are really soft and mushy. sometimes the only way to tell if it shifts is by watching the tach as you are driving, thats how smooth. i would kind of like it to be a little firmer.
Does the TPS control shift points, shift firmness, or both? What should i do to increase the firmness of my shifts.
I also checked my tranny fluid after diving about 35 miles and it is @ correct level and nice and pink, smells fine.
I am still getting the delayed forward/reverse engagement but not as bad as before.

 

['94IDITurbo7.3]

today i calculated my MPG from yesterdays 35 mile trip. i got about 12 MPG. i drove 55 mph the whole way on rual country roads w/ the only stops being stop signs. as far as i am concerned this is terrible, but is this on par for these trucks. i don't know what gearing i have in the rear end how could i find out.
my friend has the same truck just N/A and he drives it like it's a lamborghini. he was getting 12 mpg and that was because of a rotten fuel line. w/ good lines he gets better mpg than i do.

 

[lotzagoodstuff]

Figuring out your rear end gearing is pretty simple. You are basically measuring the revolutions of your driveshaft for one tire rotation. Mel has the easiest method: take a piece of string, tie it around your driveshaft, mark the string and your driveshaft together, mark on rear tire and go one tire rotation. Now count the string revolutions on your driveshaft. It should be about 3 1/2 (3.55s) revolutions or just over 4 (4.11s).

And 12 mpgs isn't great, but depending on your gearing and driving style, it might not be that faar out of reality.

 

['94IDITurbo7.3]

yesterdy i was driving it nice and like i said about my friend, my mpg just doesn't make sense.

 

[trackspeeder]

I replaced my IP yesterday. when i put my TPS back on i set it to .99V idle, which is the same place it was w/ the old IP. Guess what now my truck shifts at about 2500-2700 rpm when i drive it civilized. when i really give it then it revs up to 3000rpm then shifts. the only thing now is my shifts are really soft and mushy. sometimes the only way to tell if it shifts is by watching the tach as you are driving, thats how smooth. i would kind of like it to be a little firmer.
Does the TPS control shift points, shift firmness, or both? What should i do to increase the firmness of my shifts.
I also checked my tranny fluid after diving about 35 miles and it is @ correct level and nice and pink, smells fine.
I am still getting the delayed forward/reverse engagement but not as bad as before.

The TPS will control the speed and the firmness of the shifts to a point. You can play with the TPS to adjust the shifts. Just stay within the minimum and maximum settings. If you still don't like the shifts, look into a good shift kit.

 

['94IDITurbo7.3]

I don't know what kind of shift kit i have but the PO had one put in.
So adjusting myTPS will not change when my tranny shifts?