Throttle cable adjustment, how?

bklyn · 03-06-2009, 02:03 PM

Gents, checked my Bently but still do not know where to start on how to take the slack out of my throttle cable, any info? many thanks

gtc · gtc's Garage

Your throttle linkage should be a rod inside the center tunnel that goes from the pedal cluster, through the firewall, to an arm that pivots on a shaft sticking out of the side of the transmission. Then another rod should connect from this up to the throttle console (in the very back of your engine compartment, kind of near the oil breather), and then another rod up to your throttle body.
I think you're supposed to adjust the rod ends at the transmission-mounted pivot.

bklyn · 03-06-2009, 02:39 PM

GTC, do I just take up the slack or have someone watch the throttle plate?

Formerly Steve Wilkinson · 03-06-2009, 02:58 PM

Adjusting the throttle cable/linkage, at least with carburetors, is a black art. I tried every whichway I could and finally had to take it to a pro. Which doesn't mean you will, but be aware that "just taking up the slack" might not do it.

jcunning · 03-06-2009, 03:02 PM

Here is the procedure I used. This was for a stock 3.2 engine .

1. Check linkage at the throttle body and make sure there is .04" of gap between the idle switch.

2. Disconnect main linkage coming out of the car and adjust the linkage between engine and tranny to get the 1-2mm of slack as indicated by the book. The key point here is that this gap is created by pushing in the reverse lever by hand. If you just pull and release, there will not be any gap until you push the lever back.

3. Once this is done, you need to adjust the long linkage and the pedal at the same time. I basically used a bungee cord to hold open the throttle body to full throttle. Then I used a brick to hold the pedal down. I then went under the car to see how much distance I had between the ball of the reverse lever and the socket on the main linkage.

From there I basically had to shorten the main linkage at both locations and then lengthened the accellerator rod to get maximum travel distance.

I then tested both idle switch and full throttle switch to make sure they were working correctly. I really like using my Ohm meter with a beeping sound. Then I can be in the car and just listen for the beep to see when the full throttle sensor gets activated. On my car it is about 3/4 of the way down.

bklyn · 03-06-2009, 03:11 PM

jc, full throttle switch is also 3/4 open but I have to get under the vehicle to check the cable from the pedal.

wnsgc · 06-03-2009, 04:10 PM

Quick question. I just checked my throttle linkage by having my son step on the gas pedal til it it the stop (could not press any further). I was looking at the throttle body and the cable/rod that connects to the butterfly. With the gas pedal fully depressed, I was able to move the butterfly another 1/2" before it came to a stop (could not move any further).

Should I assume my throttle cable needs to have the slack removed?

Formerly Steve Wilkinson · 06-03-2009, 04:48 PM

As I said just a bit earlier, there's a lot more to it than "removing the slack." There are fulcrums and bellcranks and rod ends and a truly Rube Goldbergian mess of stuff between your foot and the throttle body...

jcunning · 06-03-2009, 09:18 PM

Quote:

Originally Posted by wnsgc

Quick question. I just checked my throttle linkage by having my son step on the gas pedal til it it the stop (could not press any further). I was looking at the throttle body and the cable/rod that connects to the butterfly. With the gas pedal fully depressed, I was able to move the butterfly another 1/2" before it came to a stop (could not move any further).

Should I assume my throttle cable needs to have the slack removed?

You can try just lengthening the rod at the pedal and see what that buys you.
Basically this will give you more pedal travel to hit full throttle.

If you are already fully extended at the pedal then the main line needs to be adjusted. This is step #2 in my previous post.

Steve W · Steve W's Garage

There are various reasons why the linkage lost travel over time, but the easiest place to take up the slack is under the car on the left side of the transmission. Pop off the knuckle #6 from the ball of #12, loosen #5 and shorten the linkage until when you have full throttle stepped on all the way down, there's just a business card gap to the full throttle stop at the throttle body. #6 can be hard to pop off because there's a tiny retaining pin on the side if you clean it and look closely, so pop out the pin, or just use something like a 11mm open ended wrench under it and try to pop it off.

wnsgc · 06-04-2009, 07:43 AM

Steve W.

Thanks for your response. I want to get these adjustments done before I order your chip.

Jeff & Stephan,
Thanks for your responses also. I am going to go thru this from the gas pedal to the throttle body.

I was looking at the throttle cable/rod that travels from the bell housing up to the throttle body and it appears to be a a bit worn.
When I look at this picture (the u-shaped cable on the right), I assume this is the cable/rod I need, however I cannot seem to find
it on the Pelican site. Does anyone know the "proper name" of this item and/or the part number?

Thanks again.

eapcpa · 06-04-2009, 07:54 AM

I am surprised this was not mentioned but the very first thing you need to do is check all of the bell-crank bushings. One at the pedal, the transmission and I am not sure if yours has one up top at the engine but if so, check it. The originals are plastic and they crack and break up over time. In Steve's Diagram they are #13 and #18. No amount of adjusting will fix it if the bushings are compromised. You can replace them with Bronze bushings but the original stuff does last a while. Good luck.

madmmac · madmmac's Garage

Agree with Steve as the easiest, best place to start. Adjust, double check, adjust....done in about 5 minutes. Only takes a few turns to being adjusted correctly.

Steve W · Steve W's Garage

Quote:

Originally Posted by wnsgc

I was looking at the throttle cable/rod that travels from the bell housing up to the throttle body and it appears to be a a bit worn.
When I look at this picture (the u-shaped cable on the right), I assume this is the cable/rod I need, however I cannot seem to find
it on the Pelican site. Does anyone know the "proper name" of this item and/or the part number?

Thanks again.

That's the cruise control cable.