transmission slow to shift into 4th/OD

[we4fun]

My newly aquired 86 T-Type shifts fine 1-2 and 2-3rd but takes forever to shift from 3rd-4th gear. it happens at about 50-55 MPH! Even with light throtle application. Is there anyway to remedy this? I did notice that the original or stock chip has been replaced with a Applied Technology Research chip. would this be the cause of the dealayed upshift into 4th gear? I understand that a lot of the chips out there do delay the tourque converter lock-up for better driveability. I am concerned that if I continue driving the car with this condition it will build-up more heat than when operating in a normal way. I do have a stock chip taken out of a 87 Turbo-t. would it be alright to throw it into the 86 T-type?
Also, would a minor adjustment to the throttle valve cable help shorten the shift from 3-4.

 

[Mustang 1]

Hello! I have been having a some issues with my transmission, so I have played with my tv cable alot lately. I found that if you push in from the front, effectively shortening the cable, that I had exactly the same problem. My 1 to 2 shift improved, but I had a very noticible delay in shifting from 3 to 4, especially when could. If you pull the cable out, a notch at a time, you will probably find a sweet spot were all is well. I was able to....Hope this helps.

 

[we4fun]

thanks. I will try and adjust on that cable.

 

[we4fun]

tried adjusting on cable to no avail

I tried adjusting on cabe but it still takes too long to shift into 4th (OD). now by pulling the cable forward my 1-2nd and 2-3rd shifts are weak. WHAT NEXT!