Intermittant High Idle (again)

[Grif]

Ok, put it in the shop. They were unable to find any external vac leaks. They could not rule out internal vac leaks (WTF are internal vac leaks??)

The shop found the info about the power steering pressure sensor possibly causing this, so they started to check that out, but in the process found a broken wire from an oil pressure sensor (tho the invoice indicated it was an oil pressure SWITCH) and once that wire was corrected the idel went down nearly to normal.

They were as suprised as I was.

So I got the VX back from the shop, and to me the idle is still a bit high. But at least not 2000-2600 RPM.

I had never heard of this potential cause before so I post it here. I think it will take more testing before I'm convinced because the high idle condition was intermittant anyways. I post the info from the shop here simply because it was news to me.

[Grif]

No comments? No replies? Despite the fact the I've proposed a new fix for scroggy idle probs?

Despite the fact that I requested baseline OBD measurements from you scanguage owners?


My posts have been buried. I'm feeling kinda alone here.

[Heraclid]

Mine has been doing something similar, idling around 1200 rpm, shooting up to over 2000 rpm (sometimes well over) when in neutral or park. Surging while driving, seems to be mostly during deceleration coming to a light and such. Was sitting in line at a drive-thru and it was revving up pretty good and got way hot. One time it got real hot and also had really rough transmission shifts, but only once did that happen. Inspection showed some serious oil consumption and water was low.

Had erratic idle a while back but not the surging, etc. Replaced the IAC back then, problem pretty much went away until a week or so ago when all of this started occurring.

So anyway, a little over a week ago it started surging pretty bad then getting too hot. Got a CEL when it overheated, oil & water low, changed oil, added water, new air filter while I was at it. Checked PCV, sprayed IAC and throttle butterfly valve with carb cleaner. Have not done EGR though. Has not overheated or thrown another CEL since but still was surging. Problem is intermittent, may act weird right at start-up, drive great for 30 minutes of so, then start misbehaving. Some times worse, some times not at all. No apparent leaks other than a very slow power steering fluid leak I've known about for some time. Was advised to just keep an eye on it, shop was in no hurry to replace the pump and didn't seem to think it was a big deal.

VX was finally in the shop today and the code they got indicated a faulty throttle position sensor. Would be nice if that's it because it wasn't obscenely expensive ($40 part, though that is a lot for no more than it is). Since that was replaced this afternoon it is still idling a bit high, just over 1000 rpm, but if I shift it into drive while sitting still it settles to normal idle speed. Short little drives tonight yielded no surging though, will see how it goes from here.

I forgot to tell them not to use the windows, and it seems like mechanics always do. So the window glass came off the lift mechanism, dropping the glass free into the door. Since they made no attempt to make it right after doing it and I was sort of mad about that and would pretty much just rather they didn't anyway, I had to pull the door apart tonight and get it back in place. Got that down to a science now, done it plenty. It's a wonder the glass has not broken yet. The rubber in the forward channel is totally shot and needs replacement. I like using my windows and my main gripe with the VX is I've had mine since 2003 and the windows have never worked right. Really crappy design.

[Riff Raff]

Mine has been doing something similar, idling around 1200 rpm, shooting up to over 2000 rpm (sometimes well over) when in neutral or park. No apparent leaks other than a very slow power steering fluid leak I've known about for some time. Was advised to just keep an eye on it, shop was in no hurry to replace the pump and didn't seem to think it was a big deal.

Hmmm, seems like a common malfunction in regards to the "POWER STEERING" system (faulty PS connections/pump, leaky PS reservoir, low PS fluid levels).

[Grif]

Hmmm, seems like a common malfunction in regards to the "POWER STEERING" system (faulty PS connections/pump, leaky PS reservoir, low PS fluid levels).

Correct Riff, it does seem to be a common problem. I had even mentioned it to the shop the first time I brought it in. But whats your point?

[Riff Raff]

Correct Riff, it does seem to be a common problem. I had even mentioned it to the shop the first time I brought it in. But whats your point?

My point is any other VX owner who is, has, or will experience simular high-rev symptoms may want to investigate their PS system as a possible culprit. Thanx for the feedback, as your experiences help all of us maintain our VX's in proper running condition and help solve the mystery sometimes with mechanical gremlins.

[etlsport]

some baseline numbers

Ambient Temperature 82ºF
Relative Humidity 87%
Time without running - 10Hours

Initial startup, no AC
Water Temp - 83
RPM - 960-1000
Throttle Pos - 0
Air/Fuel Ratio - 15.2
HP - 15.3
Voltage - 13.8
Intake Temp - 82
Gallons/Hr - 0.8
IGN - 16
Engine Load - 6
Closed Loop
Manifold Pressure - 4.9

Running time approx 90 seconds, AC full blast
Water Temp - 112ºF
RPM - 975-990
Throttle Pos - 0
Air/Fuel Ratio - 14.7
HP - 13.9
Voltage - 13.4-13.6
Intake Temp - 85
Gallons/Hr - 0.5
IGN - 16-17
Engine Load - 7
Closed Loop
Manifold Pressure - 5.4

Running Time approx 3 minutes, A/C off
Water Temp - 155
RPM - 940-950
Throttle Pos - 0
Air/Fuel Ratio - 14.7
HP - 10.2
Voltage - 13.8
Intake Temp - 105ºF
Gallons/Hr - 0.62
IGN - 16
Engine Load - 5
Closed Loop
Manifold Pressure - 4.4