What sensors or switches are affected by the pcv valve?
My wife's 4runner has a terrible cut and surge condition that's bad enough to bark the tires repeatedly coming up the driveway(err,err,err,err). pretty much undriveable on the road when it's acting up. The "surging" has been very erratic and intermittent for years. May go months between bouts. Gotten really bad lately. I've searched and read on the board about similar problems. I get a code 14 and have tried two different coil/igniter's with same results. I did notice today that if I pull the pcv valve the missing stops. So, I reset the computer codes and cranked the engine with the pcv disconnected: the code didn't come back! How could this affect the coil/igniter? You guys have any ideas on what the true nature of this problem could be? Thanks for your input, Aaron

well have you tried putting a new PCV valve in? One of the super simple fixes for surging is that the idle speed is set way too high, it causes fuel to cut at low rpm and then it nearly stalls causing the cold start injector to spurt some fuel in.

I am not absolutely positive this is how that problem works, I am going from memory from 6 months ago reading about surging, but I think it is mostly regarding surging idle.

Yeah, did that 6or 8 months ago and it seemed to fix the problem but it came back. It's been so erratic it's hard to pinpoint. Continual now for the most part. The PCV valve is still in the hose going to the intake manifold but pulled from the trashed grommet in the valve cover.

With the engine running I can work the linkage to give it some light throttle with a noticeable surge; pull the PCV and the surge quits; put the PCV back in placeon valve cover and surging resumes. It doesn't matter if my finger is over the valve cover end of the PCV valve or not the surging stops(it is pulling pretty strong toward the intake). I also drove it up and down the driveway(steep)with the PCV valve pulled from the valve cover as mentioned above with no hesitaions or stumbles and no trouble codes.

For "fits" and giggles, I'm going to pull the EGR and clean/check it out some. Any and all ideas are appreciated. Thanks

Change the PCV valve! If the grommet is trashed, you'll be pulling in vacuum from the valve cover, possibly intermittantly. Get both the PCV and grommet from the dealership, every aftermarket grommet I've had gets soft anf slips out of the valve cover easily.

Pulled and cleaned out the EGR valve and modulator. Made sure they worked and put them back in. Put the PCV valve back in place and cranked her up. No missing. Warmed her up to operating temp. Shut her down and checked for codes. No codes!! Drove a couple miles and checked codes. No codes!! Still need the gromett and PCV valve.

Hopefully the problem is solved. I've thought so before and was wrong. I still don't understand how the EGR affects the coil/igniter signal. Maybe a freak thing. I'll be back asking for help if the surging/missing returns. Thanks