Throttle cable bracket differences

[SuperTopo]

Can anyone confirm the differences in throttle cable brackets between a carb car and an FI car? I suspect the bracket for an FI car is longer than that for a carb car. By longer, I mean the housing of the cable is lower down on the FI bracket than on a carb bracket.

 

[JimD]

The bracket is different, the throttle cable is different and how the cable fits in the tunnel on its way to the accelerator pedal is different. BTW, the accelerator pedal mechanism is different too. Been there done that.

On a personal note. This issue was the downfall of the 78 project. Even after it was resolved I never felt like finishing the project, it still sits in the corner of the shop mocking me whenever I see it. I keep it because it is a one owner CA car that is really solid and you never know when you will need a spare X.

 

[Ics19]

The bracket is different...

But wasn't your '78 a 1300? I believe the setup is the same between a FI and *1500* carb car - I guess it depends on what the OP meant by "carb car"?

 

[JimD]

But wasn't your '78 a 1300? I believe the setup is the same between a FI and *1500* carb car - I guess it depends on what the OP meant by "carb car"?

That is true, mine was a 1300. SuperTopo's "About" says he has a 74, so I figured my experience was applicable.

 

[SuperTopo]

That is true, mine was a 1300. SuperTopo's "About" says he has a 74, so I figured my experience was applicable.

Thanks for the input Jim, I'm familiar with the different systems since I converted my '74 to '85 interior and Fuel Injection.

I had figured this out like 20 years ago, but I burnt a valve in 2011 and parked the car for a decade while I was consumed with working at startups and having a new baby until last year, when I dragged the car out of the shop and started to get it back on the road, this time with dual DCNFs. The problem is that I seem to have misplaced the throttle cable bracket that attaches to the cam cover. No problem, I have a couple of other 1500 FI engines lying around, I'll just pull off one of those. PROBLEM. The throttle cable is like an inch too short now! As you can see in the pic below, it was working fine when I parked the car, but from this pic I can't tell if the bracket was shorter than the FI one that makes the cable too short, I suspect it was.

For reference, I'm using all the same components you see in this picture, which was taken when I was digging in to find the burnt valve a decade ago, EXCEPT for that throttle cable bracket. The Bertone workshop manual has an exploded drawing of both the carb and FI throttle cables assemblies conveniently on the same page, and from comparing it does look like the carb bracket could be shorted than the FI, I'm hoping someone on this massive X community can confirm for sure since I don't have any carb motors lying around and I don't want to change the throttle cable, that job is almost as bad as changing master cylinders.

Once I sort this out, I can take my dormant X on it's maiden voyage after a decade of slumber and entropy, and will soon get it back to it's former glory.

 

[JimD]

I walked out to the garage and took some pictures of the 1300 from my 78. Looks like the bracket is part of the valve cover.

 

[carl]

The 1300 had the cable end held to the cam box linkage with a clamp. The 1500 had a ball accepting clip that threaded onto the end of the cable and attached to a ball fixture on the cam box linkage. The bracket shown in the initial post would be for the 1500 cable and Jim's bracket is for the 1300 cable.

 

[SuperTopo]

I walked out to the garage and took some pictures of the 1300 from my 78. Looks like the bracket is part of the valve cover.

View attachment 51691View attachment 51692View attachment 51693View attachment 51694

Thanks again, Jim. I have a couple of those cam covers and am on the verge of just swapping one in. I preferred the FI cover because it has the built-in stop for the throttle.

Here's the page from the workshop manual that shows the two brackets, compare item #5 in both exploded views. It implies that there are throttle cable brackets that bolt on, as opposed to being cast, to the cam cover. I think that's what I used twenty years ago to make '74 X1/9 throttle pedal/cable assembly components work with 1500 FI.

 

[dllubin]

But wasn't your '78 a 1300? I believe the setup is the same between a FI and *1500* carb car - I guess it depends on what the OP meant by "carb car"?

I think the 79 1500 carb car had a unique throttle linkage. The cam box cover on the 79 is totally different than the 1300 style cover.

 

[Dr.Jeff]

I can say first hand the bracket for a carb '79 and the one for a FI are different. And the differences are more than the length. Other components of the whole throttle linkage between those two are also different. So it will not be a direct swap for you.

 

[SuperTopo]

I can say first hand the bracket for a carb '79 and the one for a FI are different. And the differences are more than the length. Other components of the whole throttle linkage between those two are also different. So it will not be a direct swap for you.

Perhaps I haven't described my system well enough. I had sorted this out at one point in my younger life. I know parts are different and I know it's not a direct swap. What I can confirm is that the right mish-mash of different year components was working just fine on my FI conversion car for many years until I took it apart and misplaced the throttle cable bracket that attaches to the cam cover. That is the ONLY component in my mish-mash assembly that has not been re-installed because I lost the original one that was working before. So in installing an FI bracket I had lying around I found that it made the cable too short, meaning it held the housing of the Bowden cable too far from the throttle linkage. This is when I theorized that many years ago I had used a carb car bolt-on throttle bracket instead of an FI. So back to my question:

Can anyone confirm if the bolt-on throttle cable bracket from a carb car (I know some are cast, I'm asking about bolt on) holds the housing of the cable a different distance from the linkage than a bolt-on FI bracket? And if you have one, can you provide some measurements?

 

[Dr.Jeff]

That is what I was trying to convey - yes, they are different and hold the cable in different positions. Unfortunately mine are all buried in boxes while the engines/cars are torn down for restoration, so I don't have measurements to offer.

 

[Ics19]

That is the ONLY component in my mish-mash assembly that has not been re-installed

...but didn't you say you'd changed to dual DCNFs? Could it be that the link rod between carb and cam top is now different (shorter overall?) and the effect is to move the corresponding link end at the cable further away?

The manual page you posted are both 1500 linkages IMO as the cable is the 1500 style with sprung loaded pedal end etc.

I'll go and measure my '82 1500 carb bracket, but I'd guess it's going to be the same as a FI one. My '77 has the cast cam bracket and pretty sure that's the norm for 1300s.

{EDIT}
Measuring the overall height of the bracket on the engine side, point to point, i.e. from under the cable hole to the flat above the top bolt, it's 117mm (about 4 5/8 inch). HTH

 

[SuperTopo]

Ok, sorry for the wild goose chase everyone. I was going to purchase a new throttle cable today an decided to confirm if I had the earlier or later throttle pedal in my car. So I pulled back the carpet in the center tunnel and found the reason why my throttle cable was too short:

Damn cable got itself tucked under the petal return stop!!

After freeing it from the stop, the cable is magically just the right length to work with the FI throttle cable bracket.

I'm good to go!

 

[SuperTopo]

...but didn't you say you'd changed to dual DCNFs? Could it be that the link rod between carb and cam top is now different (shorter overall?) and the effect is to move the corresponding link end at the cable further away?

The manual page you posted are both 1500 linkages IMO as the cable is the 1500 style with sprung loaded pedal end etc.

I'll go and measure my '82 1500 carb bracket, but I'd guess it's going to be the same as a FI one. My '77 has the cast cam bracket and pretty sure that's the norm for 1300s.

{EDIT}
Measuring the overall height of the bracket on the engine side, point to point, i.e. from under the cable hole to the flat above the top bolt, it's 117mm (about 4 5/8 inch). HTH

Thanks Ics19, looks like the carb and FI brackets are the same...

 

[Dr.Jeff]

I can see how that might happen. And certainly explains why things suddenly didn't match as before. Good thing you found out what was going on - nice job.

I think the carb brackets for the 1300's and the '79-'80 1500 might be different. Because I know for fact my '79 carb bracket is different from my '85 FI bracket. Some day when I get to those boxes again I'll post pics.

 

[SuperTopo]

Final report on my throttle linkage. Here's the components used to make this work, all standard FIAT parts:

Cam cover: 1500 FI
Throttle cable: 1974-78
Throttle cable bracket: 1980-1987 FI
Main shaft/crank: 1974-78, no spring at the end of the cable
End pieces of crank: 1980?-1987 end stop, not sure what year the ball-end link came off of - simply flipped around to extend in the right direction
Linkage rod with ball-socket on both ends: 1974-78, bent in a Z ends up being a perfect length and clears everything
Ball welded to DCNF throttle: not sure what year, but it's the one with the long neck on the ball-

And whoalla! A linkage system that looks factory original. The one thing I messed up on was not welding the ball on the DCNF crank at the right angle to ensure I get the right kinematics and achieve full throttle. Right now I can only get about 90% throttle before the linkage hits a singularity. Time to break out the saw and welder again...

Keen observers will note the FI fuel line repurposed to feed the carbs. Yes, that's 7.5mm hose WITHOUT a clamp. Not needed and looks legit!

 

[dllubin]

Nice job converting the stock linkage to fit the dual DCNFs. When I did mine in 1980, I needed to preserve the stock setup for CA smog every 2 years so I used a separate set of parts to get from the shaft on the cam box cover to the carbs. Yours looks much more of a "factory" setup.

 

[carl]

I'm not into puzzles, jigsaw, candycrush, etc, but Fiat throttle linkage is more a puzzle than any of those! Dual carb conversion linkages are amazingly challenging for an X. You have to find the exact balance of the rod not hitting the cambox cover and getting full rotation of the throttle plates without any binding anywhere. It has to have smooth operation because let's face it, an X throttle pedal is not the smoothest and any binding in the engine bay will just magnify it. I'm a sucker for looking at pictures of what others have done...linkage porn?

 

[myronx19]

I preferred the FI cover because it has the built-in stop for the throttle.

Keep in consideration that the accelerator pedal has a spring on FI cars - so when you hammer on the accelerator pedal, it reduces the pull force on the end of the throttle cable (engine side).

I used this setup on my dual DCOE race car - helped me because I liked to smash on the accelerator pedal real hard - helped keep everything from breaking on the carb side.