2001 Lesabre idle speed

[shovelrog]

Is there a way to raise the idle speed on a 2001 Lesabre 3800 engine? It would smooth out my idling in gear shaking I'm experiencing. It's probably around 600-700 rpm in gear with foot on brake now. Raising it to 800-900 seems to smooth things out.
Thanks,

[enslow]

Idle speed is not the problem.

When was the last time you did a tune-up? Also, if your UIM is failing, that could cause a miss.

I would do plugs and wires first, and go from there.

Sent from my GT-P3113 using Tapatalk HD

[Tech II]

Actually, on a fully warmed up engine, idle speed should be around 650 in gear....

You can change the idle screw, but that may set a tps code, and may create harsh shifts.....I would clean the throttle plate and bore and the Pintle of the IAC valve, and the mating passage way of the valve, first....

Could also do a quick check of your air filter, and possible vac leaks...

[shovelrog]

Plugs & wires were just done. I looked into vacuum leaks a little, the large line to the power brake booster was the only vacuum hosed item I found. It seems smooth without a miss and only gets to vibrating when in gear. You can hear it in the dash rattling and feel it in the floor, it was fine with the wore out engine & tranny mounts. Now that they've been replaced it surfaced.

[shovelrog]

I just cleaned the IAC and that seemed to cure it. The idle in gear is much smoother and a little higher.

Thanks a bunch!!