NP993

Recently I began experiencing a sticking throttle -- the engine would hang up at 2,000 RPM's, and then higher. I tracked down the problem yesterday: the throttle cable at the adjuster (rear of the center tunnel) is fraying and digging into the sleeve it travels in. It doesn't slide in the sleeve, in other words -- hence the stickiness and hanging up.

I can't find anything in the archives about replacing the full cable with the motor in. Anyone done this? Shouldn't be too hard, but looks like a real PITA job.

Boeing 717

Well i dont know much about 993's if it is the same as a 964 the only really hard part would be getting the cable through that grommet on the engine tin in the front of the engine then onto the ball socket on the crank mechanism. On my 964 turbo most of that stuff is hidden under the intake manifold and stuff. I did it with my engine out and getting it through that grommet took me about 30 minutes in plain view. I have pictures of the areas im talking about so pm me if you want to see them, hopefully the 993 is a little more accessible.

JM993

Since you've got a 96 w/ vram, it will be a PITA, but like you say - not too hard. If you check out the vram diy in my sig you can get a better feel for the under-engine cover routing. The hardest part will be removing the old and installing the new at the engine. Your best bet is to probably lower the engine down on its mounts. This will provide you better access around the engine and transmission tunnel. The rest is self explanatory.

Good luck
Joe

chris walrod

Like mentioned above, the vario models are a PITA -- you will have to lower the engine down enough to gain access to the cable end at the throttle body. The rest will be easy.

Be sure to adjust it such that the cable doesnt go full tight at WOT -- let the pedal stop do the work

NP993

Thanks. Just what I thought as well - not too bad except for hooking it up at the engine.

I had my engine out a couple months ago to do the clutch - would have been so easy then....

NP993

Perhaps a stupid question, but which end do you start with? Do you start the cable at the tube at the pedal cluster and send it back to the engine, or do you start at the engine end?

NP993

Done. Not hard, just annoying at times.

Only problem now is that somehow my car doesn't want to idle any more. It's idling at 250 RPM's, and absolutely stalls when you take it out of gear and let the revs drop -- the needle crashes without a hiccup.

This doesn't make much sense. I had to lower and raise the engine several times as part of the process, but that's normal, and I didn't damage anything. The car drives perfectly. I wonder what's going on.

JM993

Check your vacuum connections. It isn't hard to disconnect one accidentally when working around the Vram.

Cheers,
Joe

NP993

Checked all the connections - nothing awry. Damned thing will not idle. Any other ideas?

JM993

Oil breather hoses secured too? MAF connected? Intake boot secured? ICV hoses secured, electrical plug attached? I've gotta believe that something was not reattached correctly when working around the intake manifold.

Cheers,
Joe

NP993

I'll double check but it all looked fine. The only thing I did back there was unhook the cable and hook up the new one - not much, in other words...it tries to idle at 250 but slowly sputters out, it it dies immediately, of course, if you just let the revs fall naturally by pressing in the clutch/taking it out of gear.

Otherwise it starts, runs, drives, accelerates perfectly. Totally puzzling.

geolab

hello, how did you exactly proceed to change the cable? you lowered the engine a bit and by feel ?
the symptom speaks nothing I heard of,
but there are two things I would pay attention to, while changing the cable.
First is the cable routing through the back engine black metal protection,
there are two holes, one hole is for manual cars and the outer hole is for tiptronic.
If reversed, a manual cable will be too short or a tiptronic cable will be too long,
Second is the classical throttle cable hook at the butterfly flaps, there are two seats, one for accelerator cable and one for cruise control cable, and they are the same, though one is lower than the other
are you sure about those two points ?

CalvinC4S

If you had the battery disconnected then started the car with the throttle not in the "closed" position; it will do this. It's a 96 thing

pull the battery ground off for a few minutes then reinstall. Start car with closed throttle and let it idle.



Edit to add:
Your ECU trips/flags have reset and it is goofing up the closed position.
I have done this as well. Always on 96 cars for some reason.
Car runs great but as soon as you push in clutch it falls on it's ***.

Easy fix

NP993

Calvin -- hmmm....the thing is, I never disconnected the battery. I don't think it's a vacuum leak, because it idles fine when you start it up cold. And it's starting to idle a little better -- now it's at 300 and won't die if you just let it sit like that. Definitely still has the "fall on its ***" problem when you take it out of gear.

Geo -- I'll double-check, but all I did was unhook the cable and reinstall the new one in its place -- same routing through the engine tin and grommet. Which is not to say that the bad cable could have been installed incorrectly. However, the cruise works perfectly, and did before, so I would be surprised if I had them mixed up. And also, as I mentioned above, the car starts and runs perfectly. If I'd routed the cable incorrectly and it was too short, wouldn't I actually have the opposite problem -- a too-high idle, because there wouldn't be enough slack to allow the throttle to close?

Now I'm seeing the wisdom of drive-by-wire....

CalvinC4S

Try to disconnect/wait/reconnect the battery and then start car and let it idle.

This sounds like a ECU that is not going into closed loop.

If this fails....

Make 100 percent sure that your cable is allowing your throttle to close.