Success on adapting the FI cable to the old carb guide tube
Well after throwing my hands up in frustration a couple years ago (almost to the day), I have finally overcome this enormous hurdle. I could not have done it without the expert help of my neighbor Paul. He has been racing and building cars with his family for decades. He is the guy that convinced me that we should autocross the 85 I brought home last year. And now that we have that car mechanically sorted, he decided to make me get the 78 out of the corner and onto the street.
To recap. I am swapping a 1500/FI engine into my 78 that formerly had a 1300/carb set up. I have been in way over my head from day one, but I have tried to tackle most of the work myself as a learning experience. I have certainly had help from others when I needed a hand... or a kick in the ass. BobbyB even swung by STL to give me a little of both.
This particular problem was completely unknown to me when I started this swap. I was stunned to find out that the accel system (cable, linkage and pedal) were completely different between the carb and FI model years. The cables are a different length and have different sized ferrules with different attachment methods at both ends. Here is an old pic showing the differences in the ferrules. FI on top, carb below:
There is a guide tube in the central tunnel that carries/protects the bare section of either type of cable. Unfortunately the sheaths on the two types of cables differ in length as well as in ferrule size. That means that you cannot just put an FI cable into a previously carb'd X. You need to adapt the existing tube to accept the FI cable. I had been dreaming of ways to manhandle the tube into a workable form. Or to create some type of coupler to join the two differing bits. I really don't have the tools or skill set for either.
This is where Paul stepped in. He took some measurements of the carb tube and FI ferrule. Then fired up the lathe in his garage and created a custom fitted coupler in about 30 minutes. You can see it here joining the tube to the new FI accel cable.
And here are some notes on what you are looking at:
Once the coupler was complete, the fun really begins. The carb guide tube in the tunnel is much longer than is necessary for the FI cable. Here is another old picture. You can see the tail of the carb guide tube thru the oval access hole to the left of the hand brake opening. As you have seen, the FI cable sheath extends all the way into the hand brake area, so there is probably a good 8-10 inches of excess tubage. Not a problem we usually have to deal with.
The FI cable has fixed ends that cannot be modified, so you must trim the tube incrementally until you get just enough removed so that the cable reaches from the pedal attachment to the valve cover mounted throttle linkage without any stress. This means that you have to repeatedly attach/detach the FI cable from the pedal assembly as you test fit. If you have never had to deal with the pedal end of an FI cable, consider yourself lucky. I have attached/detached that cable end at least 8 times in the last few days.
At this point, all I need to do is secure the various bits and pieces of this cable/coupler/tube puzzle. Now I can move on to unsticking the stuck flare nut on the hose connected to the slave cylinder.
