Hi all, I'm new to this forum, but I have been reading through posts. I really love this site!

I'm hoping someone can point me in the right direction with the idle problem I'm having. I'm a beginner, so please bear with me. I have an 84 with the L69, 4bbl carb (Q-Jet), and 5 spd manual that I bought a few months ago. The idle speed on the carb was set high; about 2000 rpm is as low as I can get it when warmed up. The funny thing is that when I'm driving and engage the clutch, a lot of times the engine speed will race to 5000-5500 rpm (my lead foot is not responsible - it is nowhere near the gas pedal when it starts racing). Is this normal when the idle speed is set high or is this due to some other problem? This cannot be great for my engine. This may or may not be related, but recently the car refused to start and there was a strong smell of gas coming from the engine bay. Given a couple days and a little carb cleaner, it started right up again.

Thanks!

 

T-A-One-Nine,

Welcome Aboard!

Since you've cleaned the carburetor, at least externally, you might want to lightly lubricate the linkages and throttle shaft.

One guess is that you are having some problems with the high idle cam (Items 36 and 37 in the diagram), and the lack of lubrication may be causing it to stick. You may also have some binding of the throttle plates or shaft, but if you didn't remove the throttle plate screws, the plates are not likely to be misaligned. If you did remove the throttle plates from the shaft, you may need to realign them more carefully. Still, a few drops of clean oil at the ends of the throttle shaft may be beneficial.

Another likely candidate is the throttle cable. A failing cable often frays inside its housing, causing sticking and binding. If you disconnect the throttle cable from the belcrank on the left side of the carb, the throttle lever and cable should each move freely. Disconnecting them should help you determine if the problem is the cable or carburetor. If the cable does not move very freely, you need to replace it ASAP, since a sticking cable is quite dangerous. We don't want to read about you in the newspapers before you at least become a senior member.



Good luck. Keep us posted.

 

Amen to that. I have an aversion to wrapping myself around telephone polls anyway, and it would be that much worse if I had to write about it to you guys without a "Senior Member" designation under my user name.

Thank you so much for such a straightforward and detailed answer. A problem with the cable makes a lot of sense - I've had problems with some of the other cables already. The cables, hoses, etc. on the car were not as well-maintained as they should have been and don't look like they have been replaced since the car rolled off the line in 1984.

I'll give that a try and do a tune up and let you know how things work out.

 

Quick update on this problem: the racing idle was caused by a spring in the throttle linkage that was worn out. It wasn't strong enough to pull the throttle back in after acceleration, so that when I engaged the clutch, the engine kept racing.

Hope this can come in handy for someone else.

 

Occam's Razor at work.

 

Ah, my buddy William of Occam - too true!

 

We dun got ourselves a smart one 'ere

 

To be honest, I flunked myself out of philosophy. I had to look up "Occam's Razor" real fast.

 

I never took it... I found the definition of Occam's Razor while reading about quantum physics and superstring theory I think... Not that I understand any of it, but *** damn it sounds cool...

 

True dat.

Just a little light reading on quantum physics and superstring theory, eh?

 

Yep.... It's fun stuff to read about if you can understand any of it. Too many theories though.

 

I hear ya ... I read caselaw to get my chuckles though. I thought about getting a vanity plate that says "Law Dork."