legacycentral bbs

93 Legacy L FWD 5SPD

This is my battery voltage(Brand new battery): OFF-12.4V ON Running-13.8v ON Running and fans on-13.6v

Here is my problem. When the AC is turned on or the cooling fans turn on, rpm's will bog and bounce between 0 and 800.the car will shake like its going to stall. It will still studder, also, with throttle until 2,000 rpms. The fans are turned off and it will then, cure itself and become a steady idle in ten seconds or less.
I have no idea.

AC causes the engine to chug, there's no doubt about it. My car hits high idle when I turn on the AC (it sits at 1k RPM and doesn't go below it). Maybe you need to turn up your idle a little bit. I don't think you have a charging problem.

I'd suspect the IAC valve.

Legacy777 wrote:I'd suspect the IAC valve.

Agreed. I had the idle bogging problem (only when warmed up) although since the tach only goes down to 500, it really bogs to between 0 and 500, not just 0. I poured some Seafoam (roughly 2/3 of a can) through my IAC valve, it made some nice white smoke, and my problem went away.

Here's my thread about my idle problems:

http://bbs.legacycentral.org/viewtopic.php?t=25820

Final cost for the repair -- $2 for the hose, $2 for tape, and $6 for the Seafoam. Those are probably highball estimates too. It can't hurt to try.