Engine dropping to 400rpm

**aQord** · February 23rd, 2009 08:44 AM

everytime i turn my ac on the car idle goes down to about 400rpm and picks back up at around 800rpm...and while driving...i pop it out of gear and the idle goes down to 400rpm and comes back up to 800rpm...this is with the ac on. even if i rev up the engine and have it drop...it drops down to 400rpm again and raises back up...what seems to be the problem? is my idle too low?

**s_quilicot** · February 23rd, 2009 08:57 AM

Originally Posted by aQord

everytime i turn my ac on the car idle goes down to about 400rpm and picks back up at around 800rpm...and while driving...i pop it out of gear and the idle goes down to 400rpm and comes back up to 800rpm...this is with the ac on. even if i rev up the engine and have it drop...it drops down to 400rpm again and raises back up...what seems to be the problem? is my idle too low?

what car and model?

accord ba?

**v6dreamer** · February 23rd, 2009 09:09 AM

[SIZE=2][SIZE=3]Turning on the A/C or other high drain accessories or using the power steering could lug down the engine. Idle speed would also vary as a cold engine warmed up. If in need to adjust yours, requiring a very careful adjustment of the choke and pull-off linkage is a must. Do not over do.[/SIZE][/SIZE][SIZE=2]

[SIZE=3]Check also if the EGR valve or the vacuum have a leak. Leak at the carburetor or intake manifold gasket or a leaky power brake booster. All of this can contribute your car problem.[/SIZE]

[SIZE=3]Bring your car into an A/C shop to troubleshoot the following including your idle speed sensor (ISC). If the ISC is good and the engine have no leak maybe the problem is in the wiring or the ECM.[/SIZE]

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