Hello, I'm having a lot of trouble with my pedal and would like to compare my setup with someone else. I have a 68 400 all stock and I would like to compare in particular someone's accelerator pedal connection to the throttle cable at the firewall. Mine seems to be off, the point of connection is higher than where the throttle cable comes through the firewall reducing some of my pedal travel. I am only able to obtain my idle speed at about 500rpm in drive or full throttle but not both at the same time. At 500 rpm my throttle cable is extremely taut against the inside of the firewall and my pedal hits the ground before I can reach full throttle. on the other hand, adjusting my setup to reach full throttle...I can't achieve 500rpms in drive. I can only get as low as about 900rpms. Also at full throttle in this scenario, the bottom of the accelerator pedal is a good 2 inches from the ground. Any help would be appreciated, I know it's hard to explain my problem. Any pictures of your stock 68 throttle setup would be great thanks!
Reminds me of a HALF trip to Corpus Christi 4-5 years ago....after spening the weekend there we were getting ready to cruise back to Houston...I start my car up and pedal goes "snap"...cable broke...on a Sunday 200 miles away from home....thinking "Crap, its a special order from Ames or Classic"....but , as luck has it one of our hosts (Janine) says..."my husband just bought one for us to change out a week ago"....so she calls him, 10 minutes later its there ,and two of my buddies exchange out the broken one!! ..so 30 minutes after cable broke, were on the road....
I have tried bending the pedal rod today with no luck, I still can't improve throttle range, I have also check the pedal assembly bracket at the firewall and it isn't damaged and secures tightly. I found that if I disconnect my throttle cable at the bracket by the carb and move the cable towards the front of the car a bit maybe 1/2" it allows me to achieve the correct throttle range. So that would mean something is wrong with my throttle bracket right? I'm not sure if my bracket is the correct bracket. If someone has a picture with dimensions of the correct bracket so I could compare that would be great.
The bracket looks correct and it has the part number stamped which I think is correct. Your throttle lever on the carb is wrong. I don't know if the measurements are different. If you looks at Ames Performace Catalog page 182 it shows different years. Yours look like a 70 year. Maybe they measure the same but they were diffent for each year.
Comparing the pictures of the accelerator pedal rod of yours with mine, I believe a lot of your issue is the rod not aligning with the cable. By the time the slack gets taken up with that clip starting almost perpendicular with the cable, you have pushed a lot of pedal with little cable movement.
Also, there were two different throttle brackets in '68 depending on the intake manifold part number. The 9790140 intake uses 9792242 bracket while the 9794234 intake uses an F4 bracket.
Here's a picture of mine from the left (behind the steering column) showing the straight line between the cable entrance and rod. The accelerator pedal is at rest.so every bit of pedal depression will pull cable evenly.
Bjorn's post reminds me that I should order a spare cable, not knowing when this old one might fail. I keep a spare TH400 cable because I have had to replace mine twice through the years.
Yup the new throttle lever fixed my issue. Although, with the pedal floored I still have about 1/8" more play in the throttle lever until the throttle lever makes contact with the carb base plate. Is that good enough to get full throttle? I could easily bend the pedal rod to make the throttle lever actually make contact with the carb base plate if it's necessary.
Look down the throat of the Qjet and see where your secondary throttle blades are sitting. If they are at 90 degrees with the pedal floored, you're good. If not, modification to the carb linkage can be done to achieve it. It's in Cliff Ruggles book.