Can anyone give me some advice for how to get my motor to run more smoothly? I have a 84 gs 12a with 70,000 mi a new fuel pump, new filter and many new vacume lines. (still need to replace the rest. the problem is that the idle is sort of high (1,500) and wont run any lower. under load the car has a flat spot under 2,500-3,000 rpm then pulls like a beast. it acts like it's begging to be driven hard. generaly it won't stall but every now and then it gets fussy. It has new coils, wires, plugs,cap & rotor, and air filter. Is it reasonable to expect it to idle under 1,000rpm after warm up on a 18year old car or not? I still suspect a vacume leak but can't hear if there is one or not over the clutch fan. as always thanks in advance

 

one other quick note, the leading and trailing timing seems fine as well.

 

mine idles right at 500-750rpms, after i had a buddy tighten up the throttle return spring. It would stick at 2k and wouldnt idle below 1.3k before he did that.

might try that, or maybe your AP is worn out, either flowing too much or too little you when goose it

hope that helps

 

Sounds like you still have vacuum leak. Get some carb cleaner and spray the vacuum hoses while running to see if the idle changes. If it does its just a matter of what hose to change.

 

Well I plan on continuing to replace vaccume lines ,but where is this throttle retrun spring located, so I can check that too?

 

When I first got my car it would idle at like 400rpm. sounded really cool. It was a smooth idle also.

There is a tech at my dealership who worked on it and is like some sort of messia with carbs.

With headers and a new fuel system and such I have it idling at 750 and rich for smoothness.

 

you have messed with the mixture screw too?

 

Unfortunately, I have messed with Both the Mixture and Idle Screws (Silly 84,85 carbs wrong location) I did my best to follow the write up I had on adjusting both But I still couldn't get it to where it should be. If any one can find that guide on setting the idle and mix I can't seem to find it in the archives. I would be gratefull for any help. lastly how would one check the accelerator pump for proper operation? seems I know how to get in trouble but not back out At least the Body work is coming along well.

 

Get it to idle. Turn the mixture clockwise till it starts to sound like crap; then back it off. Try to lower the idle, and do the mixture again. Repeat, repeat, repeat.
Now if your idle is as low as you can get it, and it's still too high then you must have a leak.

The leak can be anywhere! Check the carb bolts, hoses, ect; But don't forget you can have an engine to manifold leak, as well.
Do you faintly smell antifreeze?

Check the hose going from your manifold to your brake booster. Make certain that the clamps are doing their job.

After you've exhausted every possibility, then the next step is to remove all of the hoses going to the carb from the emmisions nest. Plug every single one. The threads on screws will allow leaks, so tempting as that may be, it aint gonna work.
After having sealed her up, you should try to adjust it again.
What you may find out is that it's actually a solenoid in your rats nest causing the problem.
At the very least you'll know a bit more about where the problem is.
Next is to check gaskets on manifold.
Next is to rebuild the carb.

It's a simple problem, and feels great when you fix it. But boy is it a bitch to track down~!

As far as the AP, looking down the carb while operating the throttle by hand, you should see healthy squirts from the AP nozzels located in between the primary venturis. Too little will cause a bog just as too much will. It's adjustable. Read my write-up.

 

By the Way, Antifreeze usually smells like Pancake syrup.

 

No antifreeze smell at all, of any kind. so at least it shouldn't be that. thanks for the repeat write up I will keep a copy on file for future referance. I'll let you know how it goes.