rmr25

A few months ago I cured a wandering/hunting idle condition by replacing a faulty fuel pressure regulator (after checking all the other obvious things and replacing the MAF). Now, after just completing a TB/WP job, I have this weird condition: When fully warm and the shifter in R or D, the idle is smooth at around 650 rpms. However, once I shift into N or P, the idle starts to wander between 400 and 1000, some times even hunting to a stall. On the road, and under load, everything is fine; no hesitation or unevenness through the normal range. Has anyone ever encountered this relationship between Idle in N and D? The only thing I've noted, before going very far in this, is that the P.O had platinum WR 7 DP plugs in, instead of the recommended WR 7 DCs. These platinum plugs all look ok, though.

whitefox

When you say "all the other obvious things" does this include vacuum hoses?

RDS928S

Bob,

my car does the same thing.
I have been chasing that sporadic idle hunt/bucking for almost two years. I have replaced everything except temp II sensor(which many R-listers point to as a common problem).


Keep us posted and I will do the same if I ever figure it out.

RDS

the flyin' scotsman

Have the injectors been cleaned, balanced?

RyanPerrella

temp II sensor huh, imy dle fluctuates so much that i usually have to hold my foot on the gas when i first start it up, after about 30 seconds though it settles down and after 2 minutes it idles fine. its obvious to me this is temprature dependant as the only time i have this problem is when it stone cold. Should i replace my temp II sensor?

928saregreat

A hunting idle can be caused by many things, vacuum leak, faulty maf, air temp, fuel regulator, partially plugged injector or injectors, poor leads, excessive sparkplug gap and condition, faulty caps, rotors, improper ignition advance, and a whole bunch of other things I can't think of right now. I would start simple and check the least expensive items and work from there. My cars previous owner had a problem with that and he fixed it at least on my car by cleaning/rebuilding the injectors.

Mark

Mike Frye

Hey Bob,

I just had a similar problem with mine after a tune-up (hunting idle, mines a stick, so it was just in neutral). I just came back from a test drive after finding and fixing four potential vacuum leaks, she's running great now. I think my temp 2 sensor is bad as well though. The WSM gives several resistance ranges that you should see depending on the temperature, but mine just reads wide open, no resistance at all across the terminals.

It now idles high (probably because of the sensor) but it's steady and runs a LOT smoother.

I'm getting a temp 2 sensor and I'll post the results.

Did you get the undertray today?