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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: eventhorizon66 on March 30, 2008, 03:27:41 pm
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What is the proper way to adjust the throttle cable on an '85? My 700R4 shifts fine for the most part, but refuses to let me rev above about 3800 rpm and will not down-shift from 4 to 2 under WOT (at low speeds). I have played with the TV adjustment quite a bit, to no avail. But as I was poking around I discovered that my throttle cable only gives about 90-95% of WOT, with the pedal squashed into the carpet. If I could remove about .25" to .5" of slack in the cable I would be OK.
Also for experimentation purposes I am thinking about just crimping on a small lead fishing weight to remove the desired slack to see what difference that makes. I know it's not a permanent solution but is this a bad idea for any reason?
In case there are several different styles here's a pic (http://i208.photobucket.com/albums/bb247/1985C10/throttlecable01.jpg) of my throttle cable from inside (I'm holding the throttle pedal up to expose the free-play area).
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Well you'll have to do something if your throttle isn't opening all the way with the accelerator pedal. Adjust the TV cable tighter by depressing the tab and pushing the plunger closer towards the firewall. Go one click at a time and see how it behaves but first correct your throttle cable issue
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What is your set-up like out under the hood? Do you still have the Q-jet & stock cable bracket?
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Edelbrock carb, stock throttle cable, aftermarket throttle bracket, bowtie overdrives TV-made-EZ system.
Here's a pic (http://i208.photobucket.com/albums/bb247/1985C10/engine06.jpg).
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Even, Is the TV cable slider adjustment pushed foreward all the way, or does the pedal just not have enough "snort" to adjust to the next click? I've looked at the Bowtie stuff, looks to be a nice set-up. I thought they had a base/spacer looking bracket that went under the carb for a cable bracket, No?
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The way I adjusted the TV is to set the cam all the way counter-clockwise (near where you see it set in the pic), then adjust the cable as normal (pushed all the way back toward firewall with button depressed, release button, then pull the throttle open to WOT). From there you just play with the cam position to find the best part throttle driving shift behavior. And for that purpose it works great, but at WOT, that's another story. The throttle cable just can't quite pull the carb open to WOT, hence I'm not actuating the TV all the way. The BTO system does come with a spacer bracket that holds both the TV and throttle cable, it's in my pic...look closer, under the carb, above the manifold, LOL.
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Looking at the underdash photo, I have a couple questions. Are you holding the pedal at the bottom while you took the picture? What is keeping the pedal from just laying down toward the floor a little more? Is it all the way down? Is the carb being held open out under the hood & the pedal is on the floor? If it's the way it looks to me the problem is the when you hooked up the end at the carb, it needed pushed back to hook it up, making slack under the dash (the distance is shorter than on the original carb) making your sinker idea not right, but on the right track. You could probably heat & bend the upper part of the pedal to take out the slack. I would think this would be a known problem if on every GM truck, when installing an Edelbrock carb, would end up like this. Keep us informed, Lorne
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eventhorizon66, I had to use the fishing weight trick on my blazers thottle cable in the cab. I clamped it about 1/16" from where the original clamp is. My blazer is completely stock with stock q-jet and my pedal would not open the carb to wot so therefore no matter how much adjusting of the tv cable I did it still would not shift right. After using the fishing weight trick and then letting the tv cable self adjust it now shifts perfectly.
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Well I tried the fishing weight idea and readjusting my TV cable (pushed all the way in, pulled back out by pulling carb to WOT, then pushed back in two clicks). Just got back from a test drive, shifts great. Downshifts quickly 1 or 2 gears depending on speed. I am amazed how much stronger my engine feels now. Though I would like to bend the throttle lever, as you said HAULIN, for a more permenant solution on the throttle adjustment. Thanks for all the replies guys.
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Bend the pedal up so you have more pull, then adjust the throttle cable back from the carb to take up the slack. Just a thought.