Idle up

[Tim]

When the lights are on or a large electrical load is placed on the alternator, the idle RPMs go up to about 1500.

However, when I am using the A/C the idle will stay at 800 RPMs even when the lights are on. This probably isn't good for the car.

Is there a way to adjust the idle to compensate for this? It's hard to explain, but when the A/C is on, another solenoid keeps the engine at 800 rpms, and if I were to adjust the idle up valve thingy on the throttlebody, it would screw up the settings for idling up without the load of the A/C.

Is there an auxillary idle up for electrical loads when the A/C is on?

Does any of this make sense?


Regards,

Tim

[FB71]

TIMMAHY! long time, no talk my friend!

If I remember correctly, your lovely little friend is carbed, correct?

I have to check, but I believe idle kick for electrical loads is actually handled by an air bleed solenoid. Meaning, it doesn't actually move the throttle shaft. It allows a small amount of air to carry a small amount of additional fuel through a a passage in the carb. Start checking you vacuum hoses for leaks, breaks, disconnects, etc. In the mean time, I'll look at Fester and my pubs to confirm this info.

[Mustang196t8]

On the carb'd it has that little vacuum motor (I believe that's what you would call it) which has 2 ports and are connected to 2 solenoids on the firewall. I think the connectors and hoses are brown and orange IIRC. One thing I noticed when fiddling with my car - was that the solenoids has hoses on top that connect them to air bleeds on the air cleaner. I'm not sure if they are different sizes, but if the 2 hoses got mixed up it's possible that that's causing the problem.

My car was doing pretty much the same thing for a while. At night when driving w/ headlight on - it would idle at like 1200, if I revved it , it would come down sometimes. It seems to be okay with the a/c on tho, although I do think it idles about 100 rpm lower with the a/c on (but I'm okay with that). I kinda had to fine-tune the adjustment screw on the lever that the vac motor pulls on. It's pretty touchy - a 1/4 turn makes a big difference.

I guess to kinda answer your question - the screw on the lever is independent of the regular (curb) idle setting - the big plastic screw on the passengers side of the carb. But I do think if you change the setting on the screw on the lever that the vac motor pulls - it will change the idle when the a/c is on as well. I wish I could tell you exactly how the set-up works - but I don't know. I think it varies the amount of vacuum acting on the motor by one or both of the solenoids bleeding off a certain amount of vacuum.

[Tim]

TIMMAHY! long time, no talk my friend!

If I remember correctly, your lovely little friend is carbed, correct?

I have to check, but I believe idle kick for electrical loads is actually handled by an air bleed solenoid. Meaning, it doesn't actually move the throttle shaft. It allows a small amount of air to carry a small amount of additional fuel through a a passage in the carb. Start checking you vacuum hoses for leaks, breaks, disconnects, etc. In the mean time, I'll look at Fester and my pubs to confirm this info.

How ya been? We haven't hijacked any threads in a long time...

Yep, my rollerskate is carb'd.

I know of the solenoid in question; it's round and sort of at an angle on the throttle body.

I'll have to check on that; haven't been in that part of the engine for a few months.



Regards,

Tim

[FB71]

How ya been? We haven't hijacked any threads in a long time... Tim

hmmm, quite!

[Tim]

Indubitably!