chevy47390

Hello
The idle of my venture varies; from time to time or in the cold morning everything is perfect.
But very often it goes up alone to 1500 rpm and up to 2500. On P or N but also on Drive which is very annoying since it accelerates alone while driving.
The defect is present on gasoline but also on LPG atmospheric type in this case the PCM and the TPS are not used any more.
I replaced and oiled the air control valve, but the fault persists.
By unplugging the IAC Valve when idle is OK then no more fault.

Thank you if anyone has an idea
cordially

Irish_alley

i would contact a chevy dealer ASAP. this would be a safety issue and might spark a recall or be part of one already

chevy47390

If I ask the question on a forum is that I do not want to go see a dealer and that anyway there is none in my area
Thank you if anyone has a real idea
cordially

Fried Hog

We had similar problem with 2003 Venture; when driving at 40+ MPH it acted like the cruise control was on (while it was off). It was the throttle position sensor.

chevy47390

Hello,

Thank you for your answer, I have changed and oiled the idle actuator and the defect is less common. On the OBD II reader we have the TPS position in%. This value did not change in both cases and has the same value on another vehicle without defect (between 1 and 2%).
I had concluded that the Throtle Position sensor was not in question since the information to the PCM seems good.
It could be a TPS leak, you do not specify the exact cause
cordially

Fried Hog

My apologies, I never learned the exact cause. It was many years ago. After googling around I bought 3 parts off Amazon: TPS, MAS, and something else (I forget). My wife took the van and the parts to our mechanic who replaced the TPS only. Has worked perfect ever since.

Ace Vantura

this was happening to my 01. the cruise control was applying tension to the throttle and i could 'idle' upwards of 40 mph. i unhooked it from the throttle body, turned it on and off, cleaned the switch out with electrical parts cleaner, and then reattached it. make sure that the cruise will pay out line because i think it can get tangled up in the box. mine also did the in winter and i have not had a problem again. also, the IAC and TPS may sometimes get oil in their connections on the side of throttle body so take a look at those and the wire harness while your right there. look for wear on the wire insulation or corrosion.

chevy47390

Hello,
For all this time the defect has disappeared.
I had, of course, disconnected the cable which comes from the cruise control, without success.
Remember that on this magnificent people carrier, there is no oil that would flood the engine under the hood, just like on European cars. Oil stays in the engine!
I had changed the IAC, not a new one, it was the same. I had put a drop of oil in the axis of movement without immediate result.
It should be remembered that this works fairly well by disconnecting the IAC, when the idle speed is correct (800 revolutions per minute). When the idle panics, a brief cut in the ignition makes it possible to recover a correct idle temporarily.

So, if I understand correctly, for you too, it is an intermittent fault which would occur more in winter; we therefore still do not know precisely the cause of this defect.

To be continued ....
cordially

Ace Vantura

[QUOTE=chevy47390;447719]Hello,
For all this time the defect has disappeared.
I had, of course, disconnected the cable which comes from the cruise control, without success.
Remember that on this magnificent people carrier, there is no oil that would flood the engine under the hood, just like on European cars. Oil stays in the engine!
I had changed the IAC, not a new one, it was the same. I had put a drop of oil in the axis of movement without immediate result.
It should be remembered that this works fairly well by disconnecting the IAC, when the idle speed is correct (800 revolutions per minute). When the idle panics, a brief cut in the ignition makes it possible to recover a correct idle temporarily.

So, if I understand correctly, for you too, it is an intermittent fault which would occur more in winter; we therefore still do not know precisely the cause of this defect.

it happened one more time, once more the cruise cable had tightened up. it was about two weeks ago. i cleaned the oil off the back of the throttle body and connections anyway. seals tend to leak a bit after twenty years of daily driving. there is one on top there and one on each side as well as carbon that has gotten around the boot. (before i owned it) one of my electrical connections was missing a seal when i bought the van, too.