Hey everyone! I got a '75 Cat XR7 with a stock 351W to a C4. Over the last year I had to drive this thing on the Interstate for long miles at a time. I noticed especially when the car was cold it refused to make the jump to lightspeed (3rd gear) unless the engine exceeded 4700. 1-2 shifts still worked great, making the jump at 4500 religiously. 2-3 was really slow.
I figured it was the vacuum modulator, but now after I changed it, adjusted it, and re-added the fluid to the correct level, 1-2 now shifts at 2200 in drive and it wont go into 3rd for about 10 minutes of normal driving. When it shifts, the engine revs and waits a few seconds before the transmission slowly catches and sluggishly slides into 3rd, instead of the quick pop shift it used to do. Adjusting the modulator does nothing anymore either!
What have I done????
I figured it was the vacuum modulator, but now after I changed it, adjusted it, and re-added the fluid to the correct level, 1-2 now shifts at 2200 in drive and it wont go into 3rd for about 10 minutes of normal driving. When it shifts, the engine revs and waits a few seconds before the transmission slowly catches and sluggishly slides into 3rd, instead of the quick pop shift it used to do. Adjusting the modulator does nothing anymore either!
What have I done????
