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idle and running issues for the 03 *still having issues*
Posted: Wed Nov 23, 2011 4:34 pm
by crash93ssei
What a surprise, more gremlins to work out on the 03...
2 days ago while driving home I noticed the transmission downshifted with barely any press on the gas pedal. I thought the vacuum tee underneath the supercharger snout had popped off again as I have had that problem before. Got home and while pulling down the driveway it was acting like I was giving it a lot of gas and I had to hold the brake to keep it going slow. When I stopped it just about stalled then chugged back to life enough for me to back it up. When I shut it off it was revving to about 2000 RPM. Open the hood and sure enough it was popped off and split where it goes into the intake, so I removed it and patched it temporarily with some electrical tape for and put it back together, fired it up and it was calmed down again so I thought all was well.
Went to drive it today, it fired right up and hit about 1500 RPM like normal but when it went down to the normal idle it stalled. Fired it up again and same thing. Fired it up again and tapped the gas this time and the idle went up to about 2500 and just stayed there, little more gas and it jumped to 3000 and also stayed there.
Throttle is not stuck, it is completely closing. Unplugged MAF, TPS, and IAC (separately, not at the same time) and had no effect, but engine was also cold and not in closed loop so I don't know if it even reads off the MAF yet.
Any suggestions?
Re: idle and running issues for the 03
Posted: Wed Nov 23, 2011 5:04 pm
by 01bonneSC
Test TPS and clean IAC/mating surface is where I would start.
Re: idle and running issues for the 03
Posted: Fri Nov 25, 2011 9:05 am
by crash93ssei
How do I test the TPS?
Re: idle and running issues for the 03
Posted: Fri Nov 25, 2011 2:31 pm
by 00Beast
Put a volt meter on it and see if its voltage goes smoothly from .5 or so to 4.5 or so. The big thing is no gaps in the voltage.
Re: idle and running issues for the 03
Posted: Fri Nov 25, 2011 2:42 pm
by 01bonneSC
Re: idle and running issues for the 03
Posted: Fri Nov 25, 2011 3:36 pm
by crash93ssei
TPS tested out good, .42 volts throttle closed and 4.16 volts at wide open throttle, nice sweep with no jumps or dips in voltage as throttle opens.
One thing I noticed though, I have a scan gage II and it is saying that it is going into closed loop mode not even a minute after starting the engine, even with water temps between 60 and 80 degrees.
Re: idle and running issues for the 03
Posted: Sat Nov 26, 2011 11:28 am
by crash93ssei
Thought I had it narrowed down to the IAC, though I still thought it was odd that it was going into closed loop right after starting it even with water temps at 60 - 80 degrees. Bought a new IAC and threw it on, no luck, it did the same thing.
At that point I decided to scan the car for codes with the Scan Gage II even though there was no check engine light on. Well, to my surprise there was a code, P1133 (HO2S Insufficient Switching Sensor 1) The engine was running when I found this code, of course still not running right though, idling at about 2,300 RPM in closed loop with water temp of about 100 degrees. I cleared the code and instantly the car went back to normal - open loop, idle about 800 RPM, and everything smoothed right out. I have no idea what the deal was, but I have had that code before and never had any issues like this with it, but then again I have never had any codes stored but not have a CEL on...
I swapped out to the old IAC and still ran perfect, gonna take the new one back.
Re: idle and running issues for the 03
Posted: Sat Nov 26, 2011 1:20 pm
by Archon
A failing O2 sensor seems to do strange things with these cars. Shortly after I bought my car, I had problems where driving on the highway, around 70 and accelerating a little to compensate for a slight grade, and the car would do nothing. Even though the engine was running, it did not respond at all. This would happen about the same place on the highway each time after a cold start. The only way to get it to respond was either WOT, or letting off completely, then going back to normal pressure. Idle would become erratic, but only sometimes. I had it scanned a few times, without any problem being found. Talked it over with several mechanics, who were also at a loss. About 3 weeks later, the O2 code for insufficient activity came up. Replacing the sensor took care of the problem. You may want to replace yours.
Re: idle and running issues for the 03
Posted: Sat Nov 26, 2011 1:57 pm
by crash93ssei
The one on the car is brand new, just replaced it about three weeks ago. I bought a Delphi O2 sensor just over a year ago for the car and it started throwing codes once in a while so I did a warranty exchange on it.
Re: idle and running issues for the 03
Posted: Sat Dec 03, 2011 12:56 pm
by crash93ssei
Still sort of having issues with this.
What in the world would cause the PCM to go into closed loop mode with a water temp of 80 degrees?
It seemed to run fine the last few days then yesterday we went to go out and used the remote start like normal. It fired up and idled for a little bit then started spitting and sputtering then stalled. Fired it back up and idle was high again.
IAC has been tested electrically according to a post I found on here (of course I can't find it now) and all passages are clean and free of carbon / debris.
TPS has been tested and functions perfectly.
O2 sensor is a NEW Delco unit that was swapped in maybe three weeks ago now. I am beginning to think this may be the issue as it ran perfectly fine until I swapped it in. The problem didn't happen immediately after swapping it in, but it doesn't get driven that much either.
Could a messed up O2 sensor cause the PCM to freak and go into closed loop when the engine is cold, or is that strictly supposed to be controled by the water temp sensor? Maybe the PCM is fried?
Re: idle and running issues for the 03 *still having issues
Posted: Sat Dec 03, 2011 1:22 pm
by Archon
the 80* may actually be a bit high. This is information from DTC P0125 Engine Coolant Temperature (ECT) Insufficient for Closed Loop Fuel Control. I still suggest replacing the O2 sensor.
Circuit Description
To provide the best possible combination of driveability, fuel economy, and emission control, a closed loop air/fuel metering system is used. When the vehicle is first started, the PCM controls fuel delivery in open loop, ignoring the HO2S signals and calculating air/fuel ratio based on inputs from the engine coolant temperature, throttle position, and mass air flow sensors. The PCM will begin using the HO2S 1 signal for controlling fuel delivery (closed loop) when the following conditions have been met:
The HO2S output signal is varying, indicating that the sensor is hot enough to operate properly.
The engine coolant temperature (ECT) sensor indicates a coolant temperature of more than -10°C (14°F) for VIN K or 20°C (68°F) for VIN 1.
The time since start-up is at least 15 seconds for a warm engine or 90 seconds for a cold engine.
The PCM monitors the amount of time for the cooling system to achieve closed loop operating temperature. This diagnostic is broken into 3 temperature regions. The diagnostic uses the ECT and IAT sensors to determine which region to operate in. The time to achieve closed loop temperature is monitored. A time based decision is made depending upon the temperature region. The diagnostic will monitor the following conditions prior to setting the DTC:
The total airflow must exceed a calibrated amount.
The engine idle time must be less than a calibrated amount.
Conditions for Running the DTC
No active IAT or ECT DTCs are present.
The minimum air temperature is more than -7°C (19°F).
The start-up engine coolant temperature is less than 40°C (104°).
Region 1-- The air temperature is more than 10°C (50°F) and the start up engine coolant temperature is more than -10°C (14°) for VIN K or 10°C (50°F) for VIN 1 .
Region 2--The air temperature is more than -7°C (20°F) and the start up engine coolant temperature is between -7°C (20°F) and 10°C (50°F).
Region 3--The air temperature is more than -7°C (20°F) and the start up engine coolant temperature is between -40°C (-40°F) and -7°C (20°F).
Conditions for Setting the DTC
Region 1
An engine run time of more than 6 seconds (VIN K) or 150 seconds (VIN 1) to achieve a closed loop temperature of -10°C (14°F) for VIN K or 20°C (68°F) for VIN 1.
The calibrated minimum amount of total airflow has been exceeded.
The maximum idle time is less than 5 seconds (VIN K) or 125 seconds (VIN 1).
Region 2
An engine run time of more than 154 seconds (VIN K) or 250 seconds (VIN 1) to achieve a closed loop temperature of -10°C (14°F) for VIN K or 20°C (68°F) for VIN 1.
The calibrated minimum amount of total airflow has been exceeded.
The maximum idle time is less than 120 seconds (VIN K) or 200 seconds (VIN 1).
Region 3
An engine run time of more than 287 seconds (VIN K) or 375 seconds (VIN 1) to achieve a closed loop temperature of -10°C (14°F) for VIN K or 20°C (68°F) for VIN 1.
The calibrated minimum amount of total airflow has been exceeded.
A maximum idle time of less than 225 seconds (VIN K) OR 300 seconds (VIN 1).
Re: idle and running issues for the 03 *still having issues
Posted: Sun Dec 04, 2011 3:28 pm
by crash93ssei
Ok so it appears normal to go into closed loop shortly after startup, I was thinking it shouldn't go into closed loop until the water temp was about 160 degrees.
I am gonna order a new O2 sensor and see what happens.