'95 LeSabre With P0123 Code - Info Only
timrice
10-16-2004, 07:23 PM
My '95 threw a couple of P0123 codes last week. (P0123 = "Throttle Position Sensor Input High") It seemed to be running OK even with the Check Engine light on. After shutting the engine off and restarting, the light would be off again.
Then we had a cool morning here several days ago - about 35 deg. F, and when I started it, it didn't want to kick down to normal low idle RPM. I got it out on the road, and the engine rpm just kept climbing up without any depression of the accelerator on my part. It got up around 2500 rpm before I shut it off and tried starting it again. When it started, it cranked right back to around 2500, then dropped to normal low idle after a few seconds, and the rest of the day all was well.
Got a chance to look at it this weekend, and my brother-in-law (I have to put a plug in for him--he's a gifted tech even though he doesn't do it for a living) noticed that there was evidence of some coolant seepage at the plastic/metal interface between the intake manifold and the throttle body. We noticed that it looked as if the crud had crept up onto the TPS body, which is close to that area. He moved the throttle lever and let it go, and the lever on the TPS was really slow to move back to position. It even stuck in place in a couple spots along the way. There was some cruddy build-up around the rotor.
So today, we took the throttle body off and inspected things. The gasket appeared to be in fair shape, and no coolant had gotten up into the intake, but it must have been leaking just slightly toward the lower portion of the gasket to the outside of the throttle body. We pulled all the sensors (MAF and TPS) off as well as the IAC motor, and cleaned the throttle body out thoroughly with air intake cleaner spray. We cleaned the IAC motor pintle (carefully). We replaced the TPS (BWD P/N EC3046 - $50) and gasket (Felpro 61037 -$5; I have an "L" engine code). I probably could have saved myself the $50 since I had a used TPS from a salvage '89 throttle body, but I figured since we had to pull the throttle body off the car to get the TPS changed, it was probably best to go get a new one. One other thing--the guy at the auto parts store warned me *not* to use any sealant on this gasket - he said another guy had put some blue goo on his a couple weeks ago and somehow that ruined his throttle body. I think there's some debate on whether additional sealant is OK or not; I took his advice and didn't use any--the gasket we took out did not have any extra sealant applied, either.
We put all the sensors and wiring back, checked for leaks, and so far, it looks like it's holding. The worst part was getting some of the throttle body fasteners loose, especially one on the mounting bracket that was partially obstructed by the exhaust manifold. The fasteners finally succumbed to the vast armada of tools my brother-in-law has at his disposal. Putting it back together went a lot faster. The car's going to be a little smelly for a day or two since some coolant dribbled out of the manifold while we were working on it. The job took about 2 hours.
I'm fairly certain it's fixed. Just thought I'd put this experience up on the board in case anyone else out there has a wacky throttle or a P0123 code - this potential leak point between the plastic and metal might be a good place to check.
Then we had a cool morning here several days ago - about 35 deg. F, and when I started it, it didn't want to kick down to normal low idle RPM. I got it out on the road, and the engine rpm just kept climbing up without any depression of the accelerator on my part. It got up around 2500 rpm before I shut it off and tried starting it again. When it started, it cranked right back to around 2500, then dropped to normal low idle after a few seconds, and the rest of the day all was well.
Got a chance to look at it this weekend, and my brother-in-law (I have to put a plug in for him--he's a gifted tech even though he doesn't do it for a living) noticed that there was evidence of some coolant seepage at the plastic/metal interface between the intake manifold and the throttle body. We noticed that it looked as if the crud had crept up onto the TPS body, which is close to that area. He moved the throttle lever and let it go, and the lever on the TPS was really slow to move back to position. It even stuck in place in a couple spots along the way. There was some cruddy build-up around the rotor.
So today, we took the throttle body off and inspected things. The gasket appeared to be in fair shape, and no coolant had gotten up into the intake, but it must have been leaking just slightly toward the lower portion of the gasket to the outside of the throttle body. We pulled all the sensors (MAF and TPS) off as well as the IAC motor, and cleaned the throttle body out thoroughly with air intake cleaner spray. We cleaned the IAC motor pintle (carefully). We replaced the TPS (BWD P/N EC3046 - $50) and gasket (Felpro 61037 -$5; I have an "L" engine code). I probably could have saved myself the $50 since I had a used TPS from a salvage '89 throttle body, but I figured since we had to pull the throttle body off the car to get the TPS changed, it was probably best to go get a new one. One other thing--the guy at the auto parts store warned me *not* to use any sealant on this gasket - he said another guy had put some blue goo on his a couple weeks ago and somehow that ruined his throttle body. I think there's some debate on whether additional sealant is OK or not; I took his advice and didn't use any--the gasket we took out did not have any extra sealant applied, either.
We put all the sensors and wiring back, checked for leaks, and so far, it looks like it's holding. The worst part was getting some of the throttle body fasteners loose, especially one on the mounting bracket that was partially obstructed by the exhaust manifold. The fasteners finally succumbed to the vast armada of tools my brother-in-law has at his disposal. Putting it back together went a lot faster. The car's going to be a little smelly for a day or two since some coolant dribbled out of the manifold while we were working on it. The job took about 2 hours.
I'm fairly certain it's fixed. Just thought I'd put this experience up on the board in case anyone else out there has a wacky throttle or a P0123 code - this potential leak point between the plastic and metal might be a good place to check.
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