Strange High idle

[B6A4Dave]

Driving home from work today, I put the car in neutral coasting to look at my tach and realize I was idling at 2k rpm...tested it again when I got home and I have a mysterious throttle hang and still not a normal idle.

Car boosts fine, could be a vacuum leak..but if so it must've just happened on the drive home.

if driving, and have the car in gear, clutch in.. it idles around 850-900 where it should...Im confused.

Anybody? T-Body alignment time? (again) Bad MAF? Just a really weird vacuum leak I need to track down?

Videos:
https://youtu.be/go2Dfl56lsY
https://youtu.be/6d4ZwJLQj1I

[SJorge3442]

Driving home from work today, I put the car in neutral coasting to look at my tach and realize I was idling at 2k rpm...tested it again when I got home and I have a mysterious throttle hang and still not a normal idle.

Car boosts fine, could be a vacuum leak..but if so it must've just happened on the drive home.

if driving, and have the car in gear, clutch in.. it idles around 850-900 where it should...Im confused.

Anybody? T-Body alignment time? (again) Bad MAF? Just a really weird vacuum leak I need to track down?

Videos:
https://youtu.be/go2Dfl56lsY
https://youtu.be/6d4ZwJLQj1I

Ahh. Since it doesnt do it when moving with the clutch in, I bet its related to the clutch switch. If you're moving and you and clutch, the throttle body operates differently than it does when your sitting still reving the engine. Old Guy explained it somewhere, but I can't find that post.

[B6A4Dave]

Ahh. Since it doesnt do it when moving with the clutch in, I bet its related to the clutch switch. If you're moving and you and clutch, the throttle body operates differently than it does when your sitting still reving the engine. Old Guy explained it somewhere, but I can't find that post.

Well thats the strange thing...it stopped doing it dependent of the clutch position..

On the parked video I put it in gear and blipped it and the idle didnt stay all funky like it did while driving..

[old guy]

Well thats the strange thing...it stopped doing it dependent of the clutch position..

On the parked video I put it in gear and blipped it and the idle didnt stay all funky like it did while driving..

The upper clutch pedal switch causes the throttle to hang if the clutch pedal is all the way up and the car is moving. Once you stop moving the throttle no longer hangs in relation to the pedal position. That's why you experienced it in neutral while driving but not when parked.

The purpose of the throttle hang is to make your transition from on/off throttle a lot smoother when driving the car.

[B6A4Dave]

The upper clutch pedal switch causes the throttle to hang if the clutch pedal is all the way up and the car is moving. Once you stop moving the throttle no longer hangs in relation to the pedal position. That's why you experienced it in neutral while driving but not when parked.

The purpose of the throttle hang is to make your transition from on/off throttle a lot smoother when driving the car.

So....whats causing this? its never done it before.. and ive owned this thing almost 6 years..

[old guy]

Don't know what to tell you other than it is now acting normal.

[B6A4Dave]

CEL Popped on this time...

6 ECU fault codes stored.

P0300
Random/Multiple Cylinder Misfire Detected 16684

P0301
Cyl.1 Misfire Detected 16685

P0303
Cyl.3 Misfire Detected 16687

P0304
Cyl.4 Misfire Detected 16688

P1297
Connection turbocharger - throttle valve pressure hose 17705

P0507
Idle Control System Higher than Expected 16891

P1297? aka: smoked SJP?

[B6A4Dave]

Cleared them aaaaaand...

https://youtu.be/1QKkQcIAzSc

[B6A4Dave]

I've come to the determination that Its probably time to replace my OE 2003 SJP..

My part number is, 058 133 753 B, is the 058 133 753 D a revision update?

And If I do it, I'll probably replace the connecting hose, 058 133 784 P.

I did notice when I boost leak tested the car that my SJP had a small leak..but perhaps that is part of my issue.

This seems like a really good deal if it's all legit OEM >>> Clicky Click (trademark OldGuy) <<<

[old guy]

"D" is just an updated version. and yes that looks like a terrific deal!

[old guy]

CEL Popped on this time...


P1297? aka: smoked SJP?

I doubt that code is being caused by the SJP unless it's totally separated. A small leak typically won't dump enough pressure to give you a P1297.

[B6A4Dave]

"D" is just an updated version. and yes that looks like a terrific deal!

Come to notice it now the brand is "OEM" and origin is China, just shipping out of the US..I think they're the same ones that are it the " look what showed up from china " post

I doubt that code is being caused by the SJP unless it's totally separated. A small leak typically won't dump enough pressure to give you a P1297.

I can tell ya this, after I cleared the codes, I've probably drove 300 miles and hasnt come back, and my idle has returned to normal.

note, I have a big hesitation and stutter/stumble one cold start, and for the first time today Outside of using E85 in the Colorado winter a Flashing CEL ( Severe misfire ) idling when cold..

So, thinking I may need an SJP.

That, and my dying 218.5k engine is losing compression..part of why my 2.0L stroker block is getting built.