Can't get full Throttle

[61Alpine]

I have a V6 with the original Holley 5200 2Barrel Carb. I have a Lokar throttle cable. Runs to a bracket on the front of the engine and pulls the throttle. I have had my engine out to fix a leaking Tilton slave. Done. Clutch is good. I think.

While adjusting everything we noticed that I am not getting full throw on the throttle. I am missing the last inch. I have spent a couple hours trying to figure out the problem and it looks to me like my pedal is hitting the floor before I get the full throw.

Anyone have any ideas on how to fix that.

Thanks.

 

[RootesRacer]

Tighten the cable.

This will make the throttle at idle higher up, but you will be able to get full throttle unless there is a mechanical bind.

 

[61Alpine]

Tightening the cable is not the answer. To get to full throttle I would idle at about 3000 rpm.

My best guess is some sort of modification to the pedal.

 

[64beam]

Hi,

Can you get full movement by manually moving the carburettor linkage? If you can, then as RootesRacers suggested there is something amiss with your linkage somewhere.

Regards, Robin.

 

[64beam]

Tightening the cable is not the answer. To get to full throttle I would idle at about 3000 rpm.

My best guess is some sort of modification to the pedal.

Was it working prior to removing the engine? Have you check you linkages to the pedal. I had issues with my Tiger due to linkages/clamps moving on my recent modification... ended up being a broken linkage clamp.

 

[RootesRacer]

Tightening the cable is not the answer. To get to full throttle I would idle at about 3000 rpm.

My best guess is some sort of modification to the pedal.

If tightening the cable is not the solution then your pedal to cable linkage needs less leverage (more stroke).


On my cable setup, I modified the stock pedal clamp mechanism to to have a
rod with a 45 degree bend. The cable goes through the firewall and is
clamped between two nuts on the end of the modified rod.
I chose the length of the rod so that with a nominal change in pedal position,
the cable displaces sufficiently to get full throttle from the idle position.

This is the key to having a correct correlation between pedal link and carb link stroke.

 

[61Alpine]

It looks like there is an adjustment to the top of the pedal where the cable attaches. Goes through the fire wall to the front of the engine and pulls the throttle.

I can manually put the throttle all the way. My gas pedal is hitting the floor before I get full throttle.

Now that I look at my engine, I don't think I have ever had full throttle.

 

[Bill Blue]

Rob, let us know what you work out. I had the same problem with the Ford 4 bangers, finally went to this:

Of course I've modified it since the photo was taken, but the concept works well. It would be tough to make one without a lathe.

Bill

 

[socorob]

I only get about 95% of my pull. I may eventually switch to fuel injection, so ill wait to let the tps sort that out. But I was in a upullit yard and was looking at a cars setup, i cant remember which car, only it was japanese. What they had was the line from the pedal went into the engine bay and connected to a "C" piece, that wasnt a perfect C but was like a decreasing radius. The line from the fuel injection went over it in a channel like a v belt pulley and connected to the other side of it. When you pressed the gas pedal, at first it pulled it 1:1, but progessively grew in ratio as the cable went around the offcenter C. I think it was kinda sorta the same principle bill has in his picture. If you could do something along those lines above the pedal inside the car, it would be hidden.

 

[socorob]

http://www.miata.net/garage/images/throttle.jpgThis isnt exactly it, but this is the basic idea.

 

[61Alpine]

I was thinking some kind of a cam set up would increase the throw. Just need to design and build it.

 

[MikeH]

What they had was the line from the pedal went into the engine bay and connected to a "C" piece, that wasnt a perfect C but was like a decreasing radius. The line from the fuel injection went over it in a channel like a v belt pulley and connected to the other side of it. When you pressed the gas pedal, at first it pulled it 1:1, but progessively grew in ratio as the cable went around the offcenter C. I think it was kinda sorta the same principle bill has in his picture. If you could do something along those lines above the pedal inside the car, it would be hidden.

Something like this?

 

[socorob]

yeah thats almost exactly what i saw on that car.

 

[agmason54]

can't get no...

Rob
It seems to me that the arm out the firewall hole needs adjusting inside at the pedal. If that won't get it then why not shorten the same arm on the engine compartment side so your cable will travel further.
I sawed off the original pedal doing away with all the loop of rod that goes down and back to the pedal itself.I then cut the pedal itself off and welded it back to the original rod. I left about 3or 4 inches. That way it shortened the pedal & I can drive all day with my leg stretched out instead of bent at the knee. It works great.Then I made a custom adaptor and run a bicycle cable for a throttle linkage.It is simple cheap and easy.-Just like me.
What I see looks like way too much monkey motion...
Plus I'm afraid of the 'Dark'...
Agm

 

[61Alpine]

Al,
Can you post or send me a photo of your bicycle cable set up.

Thanks,