1970 Quadrajet: Proper hole for attaching throttle cable?

[Mark E.]

1970 LS5 Q-Jet 7040205: Which hole in the carb's linkage should the throttle cable attach?

I copied the photo below from the internet showing the three holes to choose from. (Not my car. Yes, the forward mounted spring in the upper hole should not be there.)

Are multiple holes provided to tune the sensitivity and position of the throttle with the gas pedal? Or should only one of these be used?

Thanks.

[Edward J.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Mark, the position on carb. arm should make a straight line from cable bracket to arm.

[Mark E.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Mark, the position on carb. arm should make a straight line from cable bracket to arm.

So use whichever hole best achieves this?

[Edward J.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Mark, yes, throttle arm should be at rest so idle speed is normal and you don't want any binding of linkage when full throttle is achieved.

[Mark E.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

I appreciate what you're saying Edward. But for a specific application (for example '70 Corvette LS5, Chevelle LS5, full size Chevy, ...) I'm surprised that amount of adjustment would be needed to compensate for production variation. Does throttle cable height vary much in production?

Is it possible the carb's linkage is drilled for use in various applications, and each application uses a specific hole?

[Terry M.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Dumb question here, but does the AIM show you which hole to use?

[Alan S.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Hi,
Yes the AIM does show which hole is intended for the linkage stud.
There's even a detail to show it.
It's important to get the stud in the correct hole so there's room for the always popular additional return spring to run from linkage to the front engine lift bracket.
Regards,
Alan

UPC6, Sheet D2, View A.

[Edward J.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

I appreciate what you're saying Edward. But for a specific application (for example '70 Corvette LS5, Chevelle LS5, full size Chevy, ...) I'm surprised that amount of adjustment would be needed to compensate for production variation. Does throttle cable height vary much in production?

Is it possible the carb's linkage is drilled for use in various applications, and each application uses a specific hole?

Mark, the different car lines will have different cables and there is a overall difference in height of intake manifolds and carburetor linkage and can change the arm height, the cables do have some flexibility.

[Mark E.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

Dumb question here, but does the AIM show you which hole to use?

Not really. The only reference I found was UPC 6-D2, View B. It shows two holes (not 3) in the linkage, with the stud using the lower hole. It doesn't look much like the real part, hence the question. Nothing in the LS5 section.

[Edward B.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

If the 1969 L36 is configured the same as the 1970 LS5 (which I believe it is), the picture you posted has it in the correct hole. Here's mine...

Ed

[Gary B.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

This might help...
Gary

DSCN4035 (2).jpg

[Mark E.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

If the 1969 L36 is configured the same as the 1970 LS5 (which I believe it is), the picture you posted has it in the correct hole. Here's mine...Ed

Thanks Ed. This is a good example of ambiguity created by the handmade drawings used in the AIM. I wonder why photos weren't used instead? I think they had cameras in the 1960s.

You probably know this, but the protective sleeve that goes around the throttle cable is broken/missing on your car.

[Edward B.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

You probably know this, but the protective sleeve that goes around the throttle cable is broken/missing on your car.

Yeah, I'm not sure why either. Still works okay, but looks kind of funky.

Ed

[Mark E.]

Re: 1970 Quadrajet: Proper hole for attaching throttle cable?

This might help...Gary

Thanks Gary. Edward's and your replies are appreciated since the cable on my car is attached to the upper, rear most hole. This is telling me I should change that.

Nice, original looking motor! Shouldn't the vacuum line from TCS to the VAC be routed under the fuel line, not over it as shown? That's what AIM shows.