Here's the story: The 1999 Camry (4 cylinder 5 speed, ~123k miles currently) I bought as a commuter/second vehicle has had this slightly annoying issue since I bought it that I can't seem to figure out. When I start it cold, it idles a touch high at around 1100 rpms, but RPMs increase and top off around 1800 as the engine gets warm. Then, to top that off, it has a surging idle when warm but only when coasting to a stop, either with the clutch engaged or in neutral, and it throws no codes to speak of. Here's what I've done up til now in no specific order:
Replaced Air filter, plugs, wires, oil change - basic maintenance stuff.....
I've not found any vacuum leaks
Replaced OE O2 sensors
Replaced ECT sensor
Replaced the TPS
Cleaned the throttle body and OE IAC to no avail, then replaced the IAC
Replaced timing belt, drive belts, water pump, and thermostat (thermostat was stuck open)
Found a tutorial about resetting base idle by turning the key to the "Run" position 3 times before starting the car - had no effect
Pulled the fuse for the ECM, no effect
I'm not sure what my next move should be since it's a multifaceted issue. Part of my mind is saying to check/replace the VSS but it isn't giving any other indications of having a problem. It isn't a mass air car so there's no MAF to check or clean. I've thought that maybe the ACT sensor could have some kind of problem but it seems to run fine other than the idle issue which seems to defy my belief that that's part of the problem. I've thought that maybe the MAP sensor was a problem, but I tried unplugging it and it wouldn't allow the car to start so I don't think that has much of anything to do with it. It seems to be temperature as well as speed/motion dependent - maybe one, maybe both??
I just bought and received a KingBolen S500 scan tool and tried it out last night to see if anything popped up that my CarQuest code reader didn't show. It didn't give any other codes than the CQ reader had already shown - and most were my fault anyway. The only code it's thrown is for the IAC, but something's causing it to operate like it is. I've tried unplugging it and it idles and drives better, but it presented a few minor drivability problems so I plugged it back in. I fiddled with the scanner a little and ran a live stream, nothing stood out to me but I'm by no means an expert with this tool nor all of the info it can/will give. The things I remember from last night is the MAP sensor read around 4-5 PSI at an idle speed of around 1750-1800. I think the TPS said it was something like 27% open. Coolant temp was somewhere in the 200-210 range. It did not give any info about the VSS, but I wasn't moving and I think it said it wasn't available through the ECM anyway.
Like I said, I'm at a loss as to where to look next - I'm open to suggestions from those who are smarter than I.....
Replaced Air filter, plugs, wires, oil change - basic maintenance stuff.....
I've not found any vacuum leaks
Replaced OE O2 sensors
Replaced ECT sensor
Replaced the TPS
Cleaned the throttle body and OE IAC to no avail, then replaced the IAC
Replaced timing belt, drive belts, water pump, and thermostat (thermostat was stuck open)
Found a tutorial about resetting base idle by turning the key to the "Run" position 3 times before starting the car - had no effect
Pulled the fuse for the ECM, no effect
I'm not sure what my next move should be since it's a multifaceted issue. Part of my mind is saying to check/replace the VSS but it isn't giving any other indications of having a problem. It isn't a mass air car so there's no MAF to check or clean. I've thought that maybe the ACT sensor could have some kind of problem but it seems to run fine other than the idle issue which seems to defy my belief that that's part of the problem. I've thought that maybe the MAP sensor was a problem, but I tried unplugging it and it wouldn't allow the car to start so I don't think that has much of anything to do with it. It seems to be temperature as well as speed/motion dependent - maybe one, maybe both??
I just bought and received a KingBolen S500 scan tool and tried it out last night to see if anything popped up that my CarQuest code reader didn't show. It didn't give any other codes than the CQ reader had already shown - and most were my fault anyway. The only code it's thrown is for the IAC, but something's causing it to operate like it is. I've tried unplugging it and it idles and drives better, but it presented a few minor drivability problems so I plugged it back in. I fiddled with the scanner a little and ran a live stream, nothing stood out to me but I'm by no means an expert with this tool nor all of the info it can/will give. The things I remember from last night is the MAP sensor read around 4-5 PSI at an idle speed of around 1750-1800. I think the TPS said it was something like 27% open. Coolant temp was somewhere in the 200-210 range. It did not give any info about the VSS, but I wasn't moving and I think it said it wasn't available through the ECM anyway.
Like I said, I'm at a loss as to where to look next - I'm open to suggestions from those who are smarter than I.....