Idle Surging not Hunting.

SMC · 11-30-2006, 07:33 AM

Idle Surging not Hunting.

1988 911 3.2
I have had an intermittent issue with Idle Surging and then bouncing, once I give it a little gas 2K RPM's for 10 seconds or so the idle steadies.
No that the temps have dropped the surging is more common. When the car is cold in the morning no issues, if I drive the car and let it sit for a few hours
then I get the surging. I have adjust my idle and air mixture on the AFM. The ICV is new has a new HTC as well. Any other ideas? I have a cat bypass but still had the same issue with the cat on the car.

JeremyD · JeremyD's Garage

Clean the grounds to the engine, the transmission and battery. Use a little sand paper to roughen them up.

Also clean the connector from the coil to the distributor.

Check your throttle linkeage and make sure your idle switch is being activated.

SMC · 11-30-2006, 08:35 AM

Thanks I love new projects! I will let you know how it works.

Have a new coil, and wires.

Will check grounds, linkage, and switch.

jester911 · jester911's Garage

Also check rotor and dist. cap.

PatrickB · PatrickB's Garage

Is the problem at idle only? If so, you might have a bad O2 sensor...

The quickest way to clean up the idle problem is a Steve Wong Chip!!!
The stock chip normally stumbles at idle, as the mixture is really quite lean... Additional beneifit of the chip is much better performance, and better fuel economy!

If the surging is at different RPM's, Check the simple stuff first!
Then you can use the search feature... Put in "rough running" "surge"
or "hesitation" or even my handle... I chased after this for a year and a half... The most frustrating part on mine, was that it was an intermittant problem, and inconsistent at that. The roughness would be at different temps, different rpm's, etc. In the end, it was a couple of bad fuel injector's. Many people will jump in and say don't start throwing a bunch of money replacing good parts... There are obvious pro's and con's with that logic... However, most, if not all of your parts are original, they will go bad at some point! Replacing many of the original parts will save much grief down the road!!! Your car is nearly 19 years old! The stuff doesn't last forever! My engine had 135k when I replaced the injectors( 151k now.) The car has never ran smoother, or had more power in my 90k miles of driving it. I ended up replacing many original parts in chasing the demon...