Surging Idol problem

Ron.G · 04-29-2005, 04:12 AM

I found a problem with my coil wire and then made a new one.
When I replaced my alternator, I laid the coil of to the side to get it out of the way. Everything works and I'm happy again.
Then after driving a while it starts to kinda stumble a little under acceleration. No problem I'll just tweek the mixture a bit cause I think it my be to lean.
In the process I find that the coil wire is not in all the way on the coil and cap. Fixed my stumbling problem

BUT... Now when idoling the engine surges between 950 and 1000 RPM's. Thanks to me messing with the mixture screw.
So this leads me to the question of which way would I go to correct this? Is this a condition of to lean or to rich?

I've tried adjustments booth ways about a quarter turn but it is still there. Although going in the direction of richening it seems to get a little better.

Just thought I'd ask you guys and save me from getting it way out of wack.
This is on a 1980 SC CIS.
I did'nt have this problem before I went fiddling, so I'm sure it's a mix thing.

eddiehotrod · eddiehotrod's Garage

I found that a rich mixture was to blame for my bouncing idle, but I set the mixture with a gas analyzer which I think is the only way to get the correct setting.

Ron.G · 04-29-2005, 04:36 AM

Thanks.I'll try going a bit leaner and see what happens.
Whats a analyzer go for? I'd like to get one and do it right at some point. But after the total engine rebuild/calipers/rotors/alternator,
I'm not sure I could afford one.

84CAB · 04-29-2005, 04:41 AM

if the fuel adjustment doesn't work check for air leaks..I just spent weeks chasing a problem and this was one of the culprits..

eddiehotrod · eddiehotrod's Garage

I would think it's the mixture if the car ran fine before you changed the setting. I'm lucky enough to know somebody who owns a testing station, so I used the analyzer there. I'm not sure if the ones you can buy are any good, maybe get an emissions tester to set it for you.

Paulporsche · 08:04 AM

When you lean it, do so in small increments, like 1/16 of a turn at a time.
You can a lso try the push/pull method (search) but I find keeping it just shy of surging works fine.

vesnyder · vesnyder's Garage

I had a similar issue and making it more lean fixed the issue - I should probably have it done right at some point?

john walker's workshop · 08:08 AM

a quarter turn is a huge amount. go lean until the idle starts to drop off, then rich until it just recovers and runs nicely. that's usually in the ballpark if you have a good ear.

Ron.G · 04-29-2005, 08:04 AM

Thanks guys. I give it a shot.

FrayAdjacent911 · 04-29-2005, 08:08 AM

If your Idol is surging, you should switch to Survivor.

Paulporsche · 04-29-2005, 08:09 AM

Vance,
There really is no reason to have it set by others unless you have to meet an emission spec, and then you will be probably leaner than optimum. As long as you are not surging @ idle or almost stalling when coming to a stop, or popping, why not go for the best running condition you can get?

vash · vash's Garage

i was told by a mechanic that the air bypass, timing and AF mix is a "peterpaul&mary" situation, where if you monkey with one, you have to adjust the others. with enough advance notice, he will mess with my car for just a few bucks. i am not saying i dont fiddle, but i have had to take it to a pro to "correct" for my enthusiasm. if i had my own analyzer, i would be dangerous

Ron.G · 04-29-2005, 09:48 AM

Well I did it. I slowly leaned it out after getting up to operating temp and the surging is gone. Reset my idol and I'm back in busness.
Looks like the pelicans save the day again.

Now on the a master cylinder rebuild I'm not looking forward to. I must have let the MS piston travel to far when bleeding the brakes, so now the pedal slowly falls when waiting at a red light.
I'm sure I'll have a post for that one to....

Thanks again.