E4od 3-4 shifting hard?

[saburai]

Hi Gang!
So the old mule is running well with the fresh turbo, baGang by moose and injectors. If all goes well, on Monday I'll be hooking up our 30ft TT and heading from NY to Florida for the winter. Since replacing the IP I'm noticing that the 3-4 shifting is sharper and it seems like and it's wanting to downshift earlier. FIPL is a couple of months old and is set at 1.224v - 4.453v with a nice smooth progression through the range. Tranny was serviced 3-4k back with synthetic fluid and otherwise seems fine. Any ideas? Should I mess with the FIPL? Maybe bump up the WOT voltage?
Thanks!

 

[OLDBULL8]

You cannot change the WOT throttle voltage, it is what it is, the idle voltage is set from .92 to 1.20, the higher the idle voltage is set, the sharper the shifting will be, even more so with a towing load. The WOT throttle voltage cannot exceed 5VDC or it would shut down the PSOM or EECIV what ever you have.

 

[saburai]

You cannot change the WOT throttle voltage, it is what it is, the idle voltage is set from .92 to 1.20, the higher the idle voltage is set, the sharper the shifting will be, even more so with a towing load. The WOT throttle voltage cannot exceed 5VDC or it would shut down the PSOM or EECIV what ever you have.

Thanks Bill!
I'm not sure what you mean when you say that "you cannot change the WOT voltage". I'm pretty sure that I could set the WOT voltage within a range. That being said, do you think that I'd see better shifting if I reduced the idle voltage? If so, how much?
Thanks for your help!

 

[david85]

All you can do is rotate the sensor on the injector pump. So if you change the WOT setting, it will change the idle setting by the same amount.

Having said that, I think you could safely dial down the voltages by 0.15 volts to see what the change is like. Usually idle is set to 0.8-1.2V and WOT just is what it works out to be.

My only caution is that I'm not sure why your 1-2 and 2-3 shifts seem fine while 3-4 seems harsh. Hopefully messing with the sensor won't change your lower shifts for the worse. You can always change it back though.

 

[saburai]

Thanks. I realize that. So you're saying that the idle setting is the more critical for shift feel?

 

[snicklas]

Thanks. I realize that. So you're saying that the idle setting is the more critical for shift feel?

Yes!!!! Only worry about the idle side. Make sure the WOT isn't above +5 volts, but as long as it's not over that, just run it.....

Where the voltage starts (the 1-ish volt) and the increase in voltage is smooth across the range of operation, no dead spots or erratic jumps (which is easier to see with an analog meter) is much more important!!!

 

[david85]

You cannot adjust idle and WOT settings independently because they are mechanically linked. So changing the idle setting will change the WOT setting by an identical amount, and that will affect shift firmness.

The adjustment should be done at idle, with the high-idle solenoid off. Usually this is set to 1V nominal at idle, and the WOT is checked if its within the acceptable range (3.8-4.5 I think).

Higher voltage will mean harder later shifts and a tendency to kickdown sooner in the throttle ramp.

 

[saburai]

Yes!!!! Only worry about the idle side. Make sure the WOT isn't above +5 volts, but as long as it's not over that, just run it.....

Where the voltage starts (the 1-ish volt) and the increase in voltage is smooth across the range of operation, no dead spots or erratic jumps (which is easier to see with an analog meter) is much more important!!!

Thanks! I don't have a analog meter, but by moving very slow and watching, I can see that it is smooth and linear.

 

[saburai]

You cannot adjust idle and WOT settings independently because they are mechanically linked. So changing the idle setting will change the WOT setting by an identical amount, and that will affect shift firmness.

The adjustment should be done at idle, with the high-idle solenoid off. Usually this is set to 1V nominal at idle, and the WOT is checked if its within the acceptable range (3.8-4.5 I think).

Higher voltage will mean harder later shifts and a tendency to kickdown sooner in the throttle ramp.

Thanks as well. Great information.

 

[spg]

When you add the additional load of the travel trailer your shifts will not seem as harsh, I would think about leaving it the same while towing.

 

[saburai]

When you add the additional load of the travel trailer your shifts will not seem as harsh, I would think about leaving it the same while towing.

Thanks!
We're already on the road.
I bumped the idle voltage down to 1.1xx volts yesterday. Drove about 150 miles into PA pulling the trailer today. So far, so good.

 

[OLDBULL8]

I neglected to say,the FIPL/TPS idle voltage is set with a HOT engine.