As some of you know I'm building this 73 with my son and have many things to work out/through, mainly a new can and lifters being a priority, however another issue that I don't understand is when running the car and say flooring it from near stop and holding it, it shifts into second almost right away, say at 4000 rpm, if I want to run it on up I have to manually shift and hold it. I grew up on manual's and never fooled with automatics so know very little about them, can someone tell me why it shifts where it does, how you change that to make it shift at say 6000 rpm (if I'm flooring it why would I want it to shift up before it had used it's peak power) Anyone?
An adjustable modulator will allow you to fine tune your shift points. It functions off manifold vacuum. The wiped out cam was more than likely sending a poor signal to the modulator valve.
Your vaccuum modulator tells the tranny when to shift, if you want to hold it past that that point, then yes you have to do it manually,
Ahhhh Yes I assumed it had to do with vacumn and knowing the cam can cause problems with vacumn I'll wait until I get that straightened out, I just didn't understand how on all automatics I have driven if I stomp it, it runs up near redline before shifting but this thing does it at 4000-4500 rpm unless I shift it manually, I want to be able to floor it, have it run to near redline then shift itself and head towards redline before shifting again.....so your saying an adjustable mod. will fix that?
My understanding is that the vac modulator only controls part throttle shift points, the governor controls WOT shifts. I think the kick down rod controls how long it holds the gear.
great oh great looks like I'm going to have to get a manual to work and adjust this thing but thanks for the input
All the Ford modulators I've seen are adjustable... Through the vacuum port turn it clockwise a couple turns and see if that helps... If better and want higher shift point give it another turn... Assuming it has the correct length pin installed(not to short or cut) you'll reach a point it won't shift, just back off till it does... As far as cam, not your issue, low vacuum causes late/hard shifts... Your problem will be worse with higher vac...
Vac mod can be adjusted with a screw... All I know is, When you're at a dead stop (at the xwalk line) -- the time it takes you to get to the otherside of the road (right under the light pole) it is supposed to shift from 1st to 2nd regardless of speed of take off.
Wtf What in the H*** are you talking about, the distance between light poles has no baring on the shift points of a transmission regardless of speed, throttle amount or anything else......or are you making a joke and I just didn't get it
With a Automatic transmission I have always been told that the time that it takes to go from a dead stop at a light, to the time it takes to get right under the opposite side of the street (under the light) your transmission should shift from 1st to 2nd gear - regardless of acceleration. If for what ever reason your automatic transmission doesn't shift from that point to the other-side of the road you can adjust your vac module with a screw to reach that. Not sure whats not to understand with that?
