Bouncing idle from 1,200 RPM to 1,800 RPM
12-28-08, 02:31 PM
#1
Bouncing idle from 1,200 RPM to 1,800 RPM
After having searched, I tried adjusting my TPS but it didn't work. I'm with this problem since june 08, I don't know where it comes from. When I put the A/C on, the bouncing idle stops (but is still very high: 1,500 RPM). If I disconnect the boost sensor, the idle is great (1,100 RPM), but there is a lot of black smoke... 
Anyone?
Anyone?
12-28-08, 02:39 PM
#2
I also made a video... http://www.youtube.com/watch?v=KlQwRp3-3VU
The weird sound that we hear at 0:25 is the air pump... still plugged but is definitively broken.
The weird sound that we hear at 0:25 is the air pump... still plugged but is definitively broken.
12-28-08, 03:28 PM
#3
How do you know for sure the air pump is broken? DO you see the clutch spinning? Or the pulley surrounding it is just spinning and not the clutch?
Also, have you checked the IAC (idle air control), its right behind the upper intake manifold.
My suggestion is plug the map sensor back, make sure you have the correct TPS voltages and go from there. Dont jump from one thing to another, you'll get nowhere and you'll create more headaches.
Also, have you checked the IAC (idle air control), its right behind the upper intake manifold.
My suggestion is plug the map sensor back, make sure you have the correct TPS voltages and go from there. Dont jump from one thing to another, you'll get nowhere and you'll create more headaches.
12-28-08, 04:17 PM
#5
A bouncing idle is often caused by a too lean condition, or if the computer cannot achieve the correct idle speed due to the throttle body being out of adjustment, or if the IAC or BAC (whatever you want to call it) is not functioning properly. The computer will try to achieve the set target idle and will hunt if it is unable to do so. A vacuum leak will normally result in a high idle.
12-28-08, 05:35 PM
#6
How do you know for sure the air pump is broken? DO you see the clutch spinning? Or the pulley surrounding it is just spinning and not the clutch?
Also, have you checked the IAC (idle air control), its right behind the upper intake manifold.
My suggestion is plug the map sensor back, make sure you have the correct TPS voltages and go from there. Dont jump from one thing to another, you'll get nowhere and you'll create more headaches.
Also, have you checked the IAC (idle air control), its right behind the upper intake manifold.
My suggestion is plug the map sensor back, make sure you have the correct TPS voltages and go from there. Dont jump from one thing to another, you'll get nowhere and you'll create more headaches.
Yes I did. I'm really tired of that problem! The performance of the car are all perfect...
But hey, I don't know if that helps: When I get to 4k RPM (end of the 1st turbo), I hear a VERY little sound of air "psssst" during 0,1 second.... I don't know if that can be the vaccuum leak? I don't know how to check for this vaccuum leak... I just can't unscrew everything to see if there's a broken hose !?!?
Thanks guys!
12-28-08, 06:14 PM
#7
i had a high idle not too long ago and after months of trying to figure it out i found out that it was the throttle linkage that was getting stuck because the springs wherent closing the throttle all the way to the adjustment screw. if that makes any sense lol
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But I have a very high idle of 2,400 RPM!
12-28-08, 08:13 PM
#11
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Mine sounded exactly like that, I had a small vacuum leak, but what was causing it to do that was my blown lower intake manifold gasket. Like super blown right out of the car, with gasoline running down the outside of the block. It was bad. But replacing the gasket fixed the car right up.
12-28-08, 08:27 PM
#12
Mine sounded exactly like that, I had a small vacuum leak, but what was causing it to do that was my blown lower intake manifold gasket. Like super blown right out of the car, with gasoline running down the outside of the block. It was bad. But replacing the gasket fixed the car right up.
12-29-08, 02:09 PM
#14
The bouncing idle came back, but could a broken gasket/vaccuum leak cause a bouncing idle ?? It's non-sense... I heard that it can be a jammed throttle cable, or a faulty map sensor ??? The throttle cable looks okay, but how do I do to see if the map sensor is okay too ?
12-30-08, 07:25 PM
#21
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I am not an expert yet, but I would suggest you get the car is good running order before you replace the ECU with a PFC...just to eliminate more headaches before new ones start. I have had some issues with my car having a little bounce to the idle...I have a stock intake/turbos/IC, but full exhaust and no emmissions...that could be part of my problem...but it is 23 degrees and I am not into starting it right now or driving it to figure it out...
Trev
Trev
12-30-08, 11:07 PM
#22
I am not an expert yet, but I would suggest you get the car is good running order before you replace the ECU with a PFC...just to eliminate more headaches before new ones start. I have had some issues with my car having a little bounce to the idle...I have a stock intake/turbos/IC, but full exhaust and no emmissions...that could be part of my problem...but it is 23 degrees and I am not into starting it right now or driving it to figure it out...
Trev
Trev