I "fixed" my erratic idle problem!
 

This is going to sound strange, but here it goes...

My car always idles at 950rpm when cold, after it warms up, it idles anywhere between 1000 and 2000rpm. The car has been doing this for over 2 years... I've replaced all vacuum hoses, WUR, etc... to no avail.

I adjusted my clutch cable last Friday and since that time, the car ALWAYS idles at 950rpm, even when fully warmed up. Could the clutch adjustment make any difference in idle characteristics? The clutch was definitely out of adjustment and grinded when shifting into 1st or reverse. After turning the adjusting nut several full turns, the clutch works beautifully and the idle is right where it should be! Very strange!!!

any more info on the clutch cable adjustment.? You just turned the cable adj to add more pull to it? Did it also fix your shifting problem?

Harold,
Yep, I turned the adjustment nut a few turns clockwise and it fixed the shifting problems The clutch is much easier to engage and no grinding at all. I can't understand why the 2 year old erratic idle issue would clear up at the same time, but it did...

Check the routing of your clutch cable versus the throttle linkage system; it appears your clutch cable is dragging on the throttle linkage somewhere. Two primary locations are at the front driver's side of the transmission or in the tunnel near the gas pedal.

art,
didn't i tell ya? the clutch adjustment also sorts out any cis basic idle issues.. ;) muuuuuahhhh!
ryan

I get a good grinding if I attempt to shift into 1st at anything faster than a crawl. I often get a little grinding when putting it into reverse as well.

Could this be cable related?

Nik

Nik,
That sounds like the same problem I had and the 5 minute clutch adjustment fixed it 100%. My car returned to it's 2000rpm idle after it warmed up this AM. Oh well.... it's always something!!!

art,
does your car have a hand throttle or aar for warmup?
ryan

Is it possible that the idle is just adjusted too high and that it needs the hand throttle until fully warmed up?

Is it possible the clutch cable was putting pressure on the bell crank and keeping the engine throttle plate from returning to the stop? That may account for the increased idle speed?

They seem totally unrelated, otherwise.

Nope, more like worn first gear syncro. Either double clutch on the downshift, or wait until the car come to a complete STOP.

very likely cable related. if the condition has been progressive and is characterized by grinding primarily going into 1st and reverse, these are classic symptoms of a clutch simply out of adjustment. depending upon model year, the adjustment procedure varies just a little, but basically involves tightening the cable on the tranny end (unless all of the rear adjustment is taken up, in that case it might be possible at the front attachment). normally a couple turns o fthe adjustment screw is all it takes..little adjustments make big changes generally..it may take a couple of attempts to get it 'just right', but is basically a cost-free repair. good luck.
ryan

Ryan,

I use a hand throttle as my car doesn't have an AAR. My car idles at 950rpm when cold, but climbs to 2000rpm when warmed up. It doesn't do this all of the time so I'm leery of making any adjustments to the idle speed. When I ease up on the clutch the idle speed drops to normal, so it's not too bothersome for me.

Do you have a decel valve? Have you checked it for leaks? Have you plugged the line @ the top?

I'm confused here...did your symptom go away or not?

art,
hmm..are you familiar with how the hand throttle is to be properly used? when you say it idles at 950 when cold, that makes me wonder about your 'basic idle' setting being perhaps too high, so i'll review..forgive me if i'm telling what you already may know (standard pelicanite disclaimer ;)) for cold starts, the hand throttle should always be in the 'full up' position. once started, you gradually lower the hand throttle (if very high at start, maybe adjust to ~ 1200 or so)..as the car warms up and reaches operating temp (180 degrees), by this time you should have reduced the hand throttle to the closed position. for this reason 'basic idle' speed with a hand throttle car MUST BE SET when the car is at EXACTLY operating temp. if you try to start a car with a properly set hand throttle (which should cause an inital idle at full up between 2500-3500 rpm), the car should just BARELY idle.

i recommend two things: first, warm your car to exactly 180 degrees, get out and adjust basic idle at the idle air-bypass screw (mine turns easily with just fingers) to ~ 950 rpms. your car sounds like by the time it reaches operating temp, the idle is way too high because basic idle is not set correctly. second, see what happens with the hand throttle in 'full up' position on your next cold start..if it doesn't give you an initial idle in the 2k-3k range, it needs to be adjusted and there is an easy procedure to do so..remember, all the hand throttle does is physically accomplish the same thing as 'holding a little pressure' on the gas pedal..it's linked to the throttle cable via a plastic actuator between the hand throttle and actual throttle cable. without knowing for sure that your basic idle is set correctly, it's hard to go further and investigate other possibilities such as deceleration valve, etc. good luck!
ryan

Thanks Chill, I'm due for a new cable actually so that's probably contributing further to the problem.

Nik

nik,
this cable is definitely an item you always wanna have a spare around for anyway. give your adjustment screw a couple turns and see what happens..if you go too far, turn back a little. 'free' repairs are awesome.. ;)
ryan

ok...um, where is this magical screw?

edit:

Wait, I remember, under the pedal. Which way do I want to turn it?

Nik

nik,
the adjustment is made on the transmission end of the cable, but i forgot you have (i'm guessing) a 1980 tranny. the adjustment isn't very difficult, but involves a couple more steps than for the earlier model. at any rate, a search may bring up a suitable outline of these steps. probably not a lot of help, but you'll need a picture or two to understand.
ryan

Well I need a new cable anyways and I don't have the facilities to jack up my car so .... out comes the chequebook! Sadly, I've come to keep one in the glovebox.

Thanks BCC

Nik