5.3 High idle and tps issue
06-02-2017, 11:49 AM
#1
Teching In
Thread Starter
Join Date: Jun 2017
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
5.3 High idle and tps issue Ok, I'm stumped. I've looked all over the web and can't seem to find anybody having a similar issue to mine...
I have a 2000 Silverado, 5.3. Has had a decent amount of engine work done to it, which of course required it to be tuned. After I put the new engine in (before it was tuned), I would get a SES light randomly. P0121 I think it was TPS out of range or something like that. So, I put a new unit in. Keep in mind that when I swapped the motor, I had already installed all new sensors for everything, so this is TPS #2. No light for a week or 2. I fixed it, right? Wrong.
Started getting the light again randomly after a week or two. So, in my head, I'm thinking that replacing the TPS seemed to handle the situation before. Maybe I got another bad one (which completely falls in line with my luck about things). So, I buy and install TPS#3. I was getting it tuned in a couple days anyway, so I wanted to be damn sure that it was a good unit. No light after that. I told my tuner about it, and we checked out the TPS operation while he had it hooked up and all that. Looked perfect. So, he adjusted the trigger for the light to come on. Now it will only come on if it gets a reading of 0v or over 5v. Nothing in between. Finished the tune, life is good. For a while anyway.
A couple months go by, and once or twice I would get that light again. But I could shut it off and it would stay off for a long time (weeks). I didn't put much thought in to it seeing as it would usually come on when I didn't turn the key long enough for it to start. Never while just driving or anything like that. So I figured it was just be and my starting procedure.
Fast forward a few weeks, and now we're at the current issue. Probably 50% of the time I start it now, it decides to idle at about 2000 rpm. Just on a whim I decided to look at it with my scan tool, and the TPS showed the throttle to be open about 4%. I double checked my right foot.... Still on the floor not touching the pedal. Odd... So, I shut it off, unplug the TPS, turn the ignition on for about 30 seconds, replug, etc.... You know the relearn procedure. Hit the key, fired up just perfect, 750 rpm. Did fine for about a week, then the high idle again. same reading on my scan tool. Relearn procedure again. And back to normal. Over the last couple weeks, this has gotten more frequent. Like yesterday, it was fine when I got in it to go to work. But then at lunch it did it again. Did the relearn, it was fine going to lunch, fine when I left the restaurant, but did it again when I stopped for gas on my way back. That time I just let it idle high and drove back to work, but by the time I had gotten there, it settled itself down and started idling normal. I don't get it? Where do I even start? ANY help would be awesome!
I have a 2000 Silverado, 5.3. Has had a decent amount of engine work done to it, which of course required it to be tuned. After I put the new engine in (before it was tuned), I would get a SES light randomly. P0121 I think it was TPS out of range or something like that. So, I put a new unit in. Keep in mind that when I swapped the motor, I had already installed all new sensors for everything, so this is TPS #2. No light for a week or 2. I fixed it, right? Wrong.
Started getting the light again randomly after a week or two. So, in my head, I'm thinking that replacing the TPS seemed to handle the situation before. Maybe I got another bad one (which completely falls in line with my luck about things). So, I buy and install TPS#3. I was getting it tuned in a couple days anyway, so I wanted to be damn sure that it was a good unit. No light after that. I told my tuner about it, and we checked out the TPS operation while he had it hooked up and all that. Looked perfect. So, he adjusted the trigger for the light to come on. Now it will only come on if it gets a reading of 0v or over 5v. Nothing in between. Finished the tune, life is good. For a while anyway.
A couple months go by, and once or twice I would get that light again. But I could shut it off and it would stay off for a long time (weeks). I didn't put much thought in to it seeing as it would usually come on when I didn't turn the key long enough for it to start. Never while just driving or anything like that. So I figured it was just be and my starting procedure.
Fast forward a few weeks, and now we're at the current issue. Probably 50% of the time I start it now, it decides to idle at about 2000 rpm. Just on a whim I decided to look at it with my scan tool, and the TPS showed the throttle to be open about 4%. I double checked my right foot.... Still on the floor not touching the pedal. Odd... So, I shut it off, unplug the TPS, turn the ignition on for about 30 seconds, replug, etc.... You know the relearn procedure. Hit the key, fired up just perfect, 750 rpm. Did fine for about a week, then the high idle again. same reading on my scan tool. Relearn procedure again. And back to normal. Over the last couple weeks, this has gotten more frequent. Like yesterday, it was fine when I got in it to go to work. But then at lunch it did it again. Did the relearn, it was fine going to lunch, fine when I left the restaurant, but did it again when I stopped for gas on my way back. That time I just let it idle high and drove back to work, but by the time I had gotten there, it settled itself down and started idling normal. I don't get it? Where do I even start? ANY help would be awesome!
06-03-2017, 01:00 AM
#5
Teching In
Thread Starter
Join Date: Jun 2017
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
I checked the pinouts, and everything seems to be fine there. Not really too concerned with the light itself. I'm more concerned with this high idle and the TPS showing that it's open when it's not.
06-03-2017, 11:30 AM
#6
u need someone to data log and watch the tb opening %. At idle it shoud be zero. if its anything more it will idle high.
Try this:
turn the ign on for a few seconds thin off. go unplug the tps sensor. thin turn ign back on for around 15 seconds. key back off and replug the sensor. this shoud reset the tps percentage back to zero. Whenever your adjusting the throttle blade opening this is how u reset tps to zero.
Try this:
turn the ign on for a few seconds thin off. go unplug the tps sensor. thin turn ign back on for around 15 seconds. key back off and replug the sensor. this shoud reset the tps percentage back to zero. Whenever your adjusting the throttle blade opening this is how u reset tps to zero.