Another Idle issue

[Jonnie]

I dug into the VX shop manual and discovered that the "idle solenoid" I cleaned is actually the IAC. After taking it off, having the spring launch the plunger out, reassembling it, and putting it back on, the problem got worse. Would it stand to reason that this could be the problem? Will a bad IAC throw a code?

The IAC caused high idle for me.

Change the fuel filter and clean the MAF.

The MAF could be bad or just dirty. Also check the EGR valve.

Jon

[WormGod]

I would try to troubleshoot this one on your own. This problem is finicky at best and almost always inconclusive when you try to have a shop "decode" it. You tinkering away and getting your elbows dirty, one thing at a time, will yield better results. Like others have said already, start basic.

Clean MAF/check for induction breaches
PCV replacement
IAC cleanup
Fuel filter replacement
EGR cleanup (replacement?)

The ones that take a bit more elbow grease ....
FPR cleanup/replacement
Cam or Crank sensor replacement (VERY rare but I did have a crank sensor go bad and alter idle)
Manifold gasket

Chances are, 1 of these is the culprit. Hopefully it's one of the ones listed in the first list.

[housertl]

So I took it in, and the IAC was apparently not functioning at all, so it was replaced. More expensive than it could have been if I had done it, but faster than I could have gotten it done with my work schedule; it's my daily driver, and I would have hated to have to cancel my dinner date with my kid tomorrow night. The VX purrs now, fingers crossed that it lasts.

Thanks for all the advice, if I continue to have problems, I will start with the MAF and such.

[H3_VX]

I would try to troubleshoot this one on your own. This problem is finicky at best and almost always inconclusive when you try to have a shop "decode" it. You tinkering away and getting your elbows dirty, one thing at a time, will yield better results. Like others have said already, start basic.

Clean MAF/check for induction breaches
PCV replacement
IAC cleanup
Fuel filter replacement
EGR cleanup (replacement?)

The ones that take a bit more elbow grease ....
FPR cleanup/replacement
Cam or Crank sensor replacement (VERY rare but I did have a crank sensor go bad and alter idle)
Manifold gasket

Chances are, 1 of these is the culprit. Hopefully it's one of the ones listed in the first list.

I have just put all of these parts in my watch list on ebay JIC. At 78,000 miles should I have all of these valves (EGR, IAC, PCV) just cleaned or should I start replacing?