Stinkin FI drive cables!!

[Todd A.]

Good morning fellas,
I am hoping someone may be able to shed some light on the issues Im having with my 58 4900R unit. The unit is a monster eating FI drive cables, going through a half dozen so far in as many days. It does fine until I do a full power run, then usually right as I let off the cable pops. I actually suspect the distributor, since the out layer of the cable that fits into the distributor twists off every time (the end with the button on it).

I have been greasing the cables heavily with wheel bearing grease every time, and I have the repo short cable housing which matches up with the short cables (all purchased from Paragon).

I imagine there is only one company manufacturing these repos, but was curious if you all knew if there are different suppliers with varying quality levels. If not I guess I'll have to break down and replace the distributor cross shaft...

[Dan H.]

Re: Stinkin FI drive cables!!

Todd, I found Paragons cables to be very 'stiff' and not as flexible as originals. Does your high pressure pump turn freely by hand with a cable? Does the unit run without the cable housing, just the bare cable? I got an excellent repro cable from John Degregory as a spare, much more flexible than the Paragon one. Housing may be bad binding the cable up etc.? Happy hunting, let us know.
Dan

[Robert S.]

Re: Stinkin FI drive cables!!

The temporary answer is to run without the outer housing. This works surprisingly well. And, as a free bonus, the non-greasy drive cable can be removed whenever you park as an effective theft deterrent. How many Vette thieves carry spare FI drive cables?

Bob

[John D.]

Re: Stinkin FI drive cables!!

Hi Todd, Although some drive cables are better than others I would say you have other issues.
Can you post some pics of the broken cables? Are they all breaking in the same place?
Like Dan mentioned you could have hi-pressure pump issues.
Here is a test for you to do when it's quiet.
Put a drive cable in the high pressure pump. Then rotate the cable with your hand. Don't stick it in the distributor-just the pump.
Listen carefully and also feel for binding. If you hear grinding of the gears, or feel any kind of bind at all then stop. You have issues with the hi-pressure pump.
Issues could be that the spacer around the two gears isn't properly spaced. Or the pump was assembled wrong/incorrectly.

Now you said you bought a new repro drive cable and housing. Are the ends of the housing properly attached to the flexible part of the housing. Trying to say this. Is they a kink in the housing. Does the drive cable spin in the housing freely. A bind or a kink in the housing will trash a drive cable in short order.

Do you still have your old worn out housing? Want to do what the racers did/do??? Put it in a vise and cut off the distributor end of the housing off. The short solid piece where the thin square nut is. (your drive cable nut is a thin hex one). Then deburr the inside of this cut off hunk. Then put one of you new drive cables in the high-pressure pump/distributor with just the short piece holding it into the distributor. No grease needed.
Go for a ride and put the pedal to the metal? If you break the cable then it isn't the cables fault. It's the pump.

If the hi-pressure pump is binding stop right here and attend to that problem. Cables are cheap. Pumps cost a fortune.

The last cables GM sold-the ones in the blue/clear plastic bags were Too rigid. A good cable needs to be quite flexible. Nothing like a good used original although some have a decent cable.
What the world needs though is a super drive cable made by someone who knows what he is doing. A pal has a decent one though.

[John D.]

Re: Stinkin FI drive cables!!

Todd, Just reread your original post. Lets think about this. When you rev up your engine and you consistently twist off the cable at the distributor end what does this tell you?
It tells you that you may have pump problems.

[Dan D.]

Re: Stinkin FI drive cables!!

Make sure your repro cable is not wound backwards. GM had this problem many many moons ago. Seems to me it would be an easy mistake to make. -Dan-

[Todd A.]

Re: Stinkin FI drive cables!!

Pictures of the cable

[Todd A.]

Re: Stinkin FI drive cables!!

Thanks for the help guys, the post this morning was a little venting... Dan, JD thanks for the suggestion to try turning the gear pump - it turns smoothly and easily and then gets tough at one spot. Wouldn't call it a bind, but need all my finger strength to move it past that point.

What didn't make sense to me was the phenomenon of the cable popping when I let off, since at that point the heavy load on the pump drops off.

I'll have to pull the pump. JD, I'll give you a call Monday to discuss and order some new drive cables!

[John D.]

Re: Stinkin FI drive cables!!

Todd, Nice pics-well at least the quality of them. Also I see you have a can of my favorite Kroil penetrating oil. Good stuff.
Todd-I haven't seen a cable twisted off like yours in quite a while. That's a nasty break. That bind in the pump is your problem I bet. Goodnite, JD