Idle RPM problem
#11
Not that I can find, Magnet. I spent a long time looking yesterday afternoon. I hope to get home before dark tomorrow, maybe get another look at it. I don't hear or feel any odd vacuum problems under the hood either. Truck is running fine, has a little more power than it did before the tune up. The idle seemed to settle down some this afternoon coming home, was barely goosing up just a bit and then coming back down. Maybe the PCM had to re-learn the old IAC after I had moved the pintle shaft like I did. I am hoping this new one will settle down too.
Jimmy
Jimmy
#13
Hey Magnethead, or anyone else who might know...one thing I just thought of. Yesterday when I pulled the plug wires off a couple of my plugs, the wire boot was stuck on there pretty tight. I mean I had to yank on it hard to get it loose. I wonder if those 2 wires might have stretched the wires inside so now they don't make as good a connection? Can an engine still run OK or maybe run with a slight problem like a weird idle fluctuation with a couple plug wires that might be stretched like that?
Thanks
Jimmy
Thanks
Jimmy
#14
Hey Magnethead, or anyone else who might know...one thing I just thought of. Yesterday when I pulled the plug wires off a couple of my plugs, the wire boot was stuck on there pretty tight. I mean I had to yank on it hard to get it loose. I wonder if those 2 wires might have stretched the wires inside so now they don't make as good a connection? Can an engine still run OK or maybe run with a slight problem like a weird idle fluctuation with a couple plug wires that might be stretched like that?
Thanks
Jimmy
Thanks
Jimmy
#15
Drove it to work today, idle was fine until it warmed up to operating temp. After that when I would stop at a red light the idle was back to surging form 700 to about 850 then back down again. It does it about every 10 seconds. I don't think the plug wires are bad, there is no spitting, hesitation or sputtering, no lack of power. Truck runs fine, just has this weird idle problem that showed up after I did the tune up.
I may try a new TPS. Thanks for your help.
Jimmy
I may try a new TPS. Thanks for your help.
Jimmy
#16
I picked up a new TPS at Auto Zone on my way home from work tonight. I installed it a few minutes ago, it *appears* to have solved the problem. When I first put it on, I still had the fluctuation in RPM at idle. I let the truck run a few minutes, held the throttle at 1500 and 2000 RPM for a few seconds each, let it off, it idled back down to 700 and is now idling steady at 700 RPM sitting still in my driveway at normal operating temperature. I hope this is the final piece of the puzzle, that it really is fixed now. I have to drive it to work tomorrow to know for sure.
Thanks for your help Magnethead. I sure hope I am done with this problem for good now.
Jimmy
Thanks for your help Magnethead. I sure hope I am done with this problem for good now.
Jimmy
Last edited by 01SilverCC; 11-13-2013 at 08:06 PM.
#17
I picked up a new TPS at Auto Zone on my way home from work tonight. I installed it a few minutes ago, it *appears* to have solved the problem. When I first put it on, I still had the fluctuation in RPM at idle. I let the truck run a few minutes, held the throttle at 1500 and 2000 RPM for a few seconds each, let it off, it idled back down to 700 and is now idling steady at 700 RPM sitting still in my driveway at normal operating temperature. I hope this is the final piece of the puzzle, that it really is fixed now. I have to drive it to work tomorrow to know for sure.
Thanks for your help Magnethead. I sure hope I am done with this problem for good now.
Jimmy
Thanks for your help Magnethead. I sure hope I am done with this problem for good now.
Jimmy
#18
Spoke too soon..idle is still pulsing up and down every 10 seconds or so, but is not as bad as it was before. I guess I need to keep looking for a loose or cracked hose or some other vacuum leak. That is the only thing I can think of that would cause this idle fluctuation...I will leave it alone until the weekend, try to see what I can find in the daylight on Saturday. I am pretty tired of it right now.
Jimmy
Jimmy
#19
Maybe I spoke too soon again....
My truck ran beautifully coming home from work, I can definitely tell the new TPS made a ton of improvement. The throttle response is much more crisp and precise and the dead zone at 60 mph is long gone. I could not really test that in the morning commute traffic today but I was able to get on it coming home. My truck is a lot more responsive now.
Coming home when I stopped at a red light 4 or 5 miles from work the idle was normal, precisely at 700 RPM and steady. There was no fluctuation at all. Same thing at a couple more lights here in town and the same thing also happened in my driveway when I got home. Steady 700 RPM. The gas needle does not look like it is dropping as fast now either.
I am thinking/guessing the PCM needed more driving time to learn and calibrate the new TPS. I am calling it done and leaving well enough alone unless it starts the wonky idle again.
Thanks again for your help Magnethead.
Jimmy
My truck ran beautifully coming home from work, I can definitely tell the new TPS made a ton of improvement. The throttle response is much more crisp and precise and the dead zone at 60 mph is long gone. I could not really test that in the morning commute traffic today but I was able to get on it coming home. My truck is a lot more responsive now.
Coming home when I stopped at a red light 4 or 5 miles from work the idle was normal, precisely at 700 RPM and steady. There was no fluctuation at all. Same thing at a couple more lights here in town and the same thing also happened in my driveway when I got home. Steady 700 RPM. The gas needle does not look like it is dropping as fast now either.
I am thinking/guessing the PCM needed more driving time to learn and calibrate the new TPS. I am calling it done and leaving well enough alone unless it starts the wonky idle again.
Thanks again for your help Magnethead.
Jimmy
#20
Maybe I spoke too soon again....
My truck ran beautifully coming home from work, I can definitely tell the new TPS made a ton of improvement. The throttle response is much more crisp and precise and the dead zone at 60 mph is long gone. I could not really test that in the morning commute traffic today but I was able to get on it coming home. My truck is a lot more responsive now.
Coming home when I stopped at a red light 4 or 5 miles from work the idle was normal, precisely at 700 RPM and steady. There was no fluctuation at all. Same thing at a couple more lights here in town and the same thing also happened in my driveway when I got home. Steady 700 RPM. The gas needle does not look like it is dropping as fast now either.
I am thinking/guessing the PCM needed more driving time to learn and calibrate the new TPS. I am calling it done and leaving well enough alone unless it starts the wonky idle again.
Thanks again for your help Magnethead.
Jimmy
My truck ran beautifully coming home from work, I can definitely tell the new TPS made a ton of improvement. The throttle response is much more crisp and precise and the dead zone at 60 mph is long gone. I could not really test that in the morning commute traffic today but I was able to get on it coming home. My truck is a lot more responsive now.
Coming home when I stopped at a red light 4 or 5 miles from work the idle was normal, precisely at 700 RPM and steady. There was no fluctuation at all. Same thing at a couple more lights here in town and the same thing also happened in my driveway when I got home. Steady 700 RPM. The gas needle does not look like it is dropping as fast now either.
I am thinking/guessing the PCM needed more driving time to learn and calibrate the new TPS. I am calling it done and leaving well enough alone unless it starts the wonky idle again.
Thanks again for your help Magnethead.
Jimmy