I Can't Win! IDI Throttle Cable
 

The throttle cable on my '88 7.3 has been giving me fits ever since I purchased the truck. When I put my foot to the floor, the throttle had a tendency to stick open, and the pedal would only release after I kicked it back with my foot. Being that a new throttle cable was relatively inexpensive, I just replaced it, hoping the problem would be resolved.

No such luck.

It was actually relatively problem free for the last four months or so, and then it started binding again. So I put a heavier spring on the injection pump, thinking that would finally solve it.

It stopped binding, but the pedal became even more obscenely hard to press, to the point that it was almost a workout to do it.

Well, then the plastic bushing that sits at the top of the pedal arm to catch the end of the cable disintegrated. So I had to use some large split shot to take up the slack in the cable.

And then, this morning, a cold morning, the pedal starts sticking again!!

I'm tired of throwing temporary fixes at this thing. I need it fixed, once and for all. It's my understanding that you should be able to work the throttle with a few fingers, just like every other vehicle out there.

I've verified that the injection pump is not the problem. Any ideas?

Did you try unhooking the cable and checking it for proper function? I guess the other thing I would try is to remove the cable assembly from the truck and try spraying some WD40 or a comparable spray lubricant in the end of the sheath. Work it in and out while spraying it periodically. I would think that should take care of it. My guess is the braided cable inside could be fraying and getting snagged up inside the sheathing. I've had this issue with one of my old gassers.

No, I have not tried it with the new cable, but I tried it with the cable I replaced and it didn't help. It still functioned smoothly when I removed it from the truck, but I replaced it anyway because I had the new one in my hand.

I suppose there's two separate issues I'm trying to deal with. One is the fact that the pedal sticks to the floor sometimes. The second is that the pedal is ungodly hard to actuate. It should be smooth and easy to work simply with a motion of my ankle. It shouldn't take my entire leg to get the pedal to the floor. Right?

Pedal should be easy to operate.
Is it kinked or sharply turned anywhere?
When you unhook the cable, how does the bare pedal feel? It should flop around with basically no effort at all, maybe you need to free up the pedal itself.

The pedal on its own articulates freely. There's no binding in the pedal arm. It does have a few turns in it, simply due to the length. I can see how it would have a more direct path if it were shorter, but it's the same as the one I pulled out of it when I bought it.

Perhaps I should look into shortening it?

try hanging it up and soaking it with a grease or cable lubricant. unbolt the pedal assembly from the truck and check the pivot point for unusual wear. Only thing I can think of is when there is pressure from the cable pulling it at the top of the arm, it gets in a bind. Even try unhooking the end of the cable from the pedal assembly and pulling on the end with pliers, see how it moves.

I haven't had any luck my self with after market cables, go to a junk yard and get one, one of a fuel injected small bock will work, also check that you cable hasn't been melted by the turbo

I have verified that the sheath is not being melted by the turbo.

What benefit have you seen in using one off an FI small block, as opposed to the proper part for this engine?

Also, how does your pedal feel? Is it easy to manipulate with your hand?

Have you checked the FIPL/TPS on the opposite side of the IP from the throttle assembly? Is it binding...or is the IP shaft rotating freely? Just a thought.


Never mind, you have the five speed.

there are three or four different length throttle cables. if the one you put on is not the proper length for your engine, you will get binding.
for the diesel the throttle cable should be 42.25 to 42.5 inches long

Well, the battle rages on.

One of the pieces of split shot that I crimped on the end of the cable popped off tonight.

I'm not in a position to do much in the way of mechanical work right now, but need my truck operable.

Tom, according to the specs online, the cable currently in the truck is 42.2" long.

The small bock was what I had and it would be easier to find in a junkyard, it works just fine. It's been in my 88 since may this year

Alright, I'll look into it. What makes the small block throttle cable superior?

He's saying the AFTERMARKET cables are not the best. The OEM gasser cable isn't superior to the OEM IDI cable, just that it works fine in this application, better than the aftermarket ones.

With the cable off, move the pump lever. It should move quite freely, just like a carb lever. If you have to crank on it to move it, something's wrong.