Hi Guys,
I've been struggling to find a vacuum leak for a while now. I've replaced the intake & runner gaskets and the vacuum lines. I've tried unplugging the brake booster hose, unplugging the fuel pressure regulator and the vacuum line next to it. Yet I still have a surge at idle! Last night I readjusted the valves. But still surges. The IAC is new and the throttle body is clean. I've sprayed carb cleaner everywhere but simply can't find it.

If anyone has any ideas, please let me know... I'm running out of ideas

Just wondering... would an exhaust leak cause the engine to surge?

Thanks!

 

anyone?

 

Do you KNOW you have a vacuum leak? Have you hooked up a vacuum gauge to a port and checked?

 

A sticky EGR valve can pass a big part-time leak that's hard to trace.

Another guess would be your new IAC needing a reset to "0" counts, if you have not already done so.

Do you smell a strong gas odor sometimes??

 

Have you checked your EGR valve and other emissions related vacuum hook-ups?

 

Thanks for the replies!

The EGR has been deleted (see sig). I don't smell gas. I have reset the base idle on the throttle body but it didn't help. How do you reset the IAC???

 

look

https://www.thirdgen.org/tpimod2

 

Thanks, but I already did this.

My motor will idle fine for a little bit then surge ~200rpm... then idle fine, surge etc.