Truck won't shift at WOT

[Redline Motorsports]

My experience with this issue has lead me to believe that this is a mechanical vs. electronic issue. You can command things all day long but the delay can be because you are commanding things that also rely on a mechanical movement to take place. I have seen a few "broken" parts in the tranny cause the 1-2 shifts not to respond to any shift changes............

This may not apply in your case but some food for thought regarding shift points.........

[joecar]

Well, just an update. I now have my 1-2 shift set at 40mph/5900 RPM and my 2-3 shift set at 75mph/5000 RPM and they both shift right around 5900. Another member told me that vacuum modulation messes with some of the settings (confuses the PCM??), so I guess it's kind of a crapshoot to figure out the correct settings to use. Oh well, at least it's working now. Thanks for the help everyone.

Instead of 75MPH, try setting this down to 65MPH and see if the shift moves closer to 5000RPM; if it does then just fine tune the RPM.

[thunder550]

I like the 5900 RPM shifts, that's what I was trying to get to anyway. Now my problem is this: the lower I go with the upshift mph, the lower I have to go with the downshift mph as well. If my downshift mph is higher than my upshift, the PCM never commands a shift. I want my downshift mph's to be as follows: 2-1 @ 50 mph, 3-2 @ 95 mph.

Since my upshift speeds are set 1-2 @ 40 mph and 2-3 @ 75 mph, I have to have the downshift speeds set lower. I'm not sure that there's going to be a way around this one...

[joecar]

you can try this:
set your WOT RPM low (say 4500 RPM) and increment the WOT upshift speed until it shifts at the MPH you want,
and then set the WOT downshift speed to 5 MPH less than this.

I don't know why it's so fuzzy like this, it seems to be way off.