blkstealthpaid4

It seems to get worse, usually when it is cut off for about 15 minutes and I start the car, it would start but idle rough until I raise the RPM for about 10 sec and then it will begin to idle normal.At other times it will start normmlly.I just changed the plugs and not the wires and it is still doing the same thing.I am getting no codes.Early in the morning when I first crank it, it starts normally.I am perplexed.If it is some kind of MAS, I should at least get a code.

blkstealthpaid4

I am thinking IAC but I may be wrong.

blkstealthpaid4

A mech. recommended cleaning the throttle body and so I tried 2 cans of seafoam through the brake booster hose.I will see in a couple of days.

Jussjoshin

A dirty TB would cause a more consistent issue. Techs say that when they don't know what's really going on. It does sound like it could be a number of issues. I would start with the basics. Try unplugging your MAF to see if the problem persists. If not. Plug it back in and see if it dies. Also I wouldn't worry about your plug wires. As they start to go bad you will get a misfire under loa until finally they will misfire at idle. A sticky iacv could cause this problem as well. Diaging an iac can be a pain sometimes though. If you have access to an obd1 scanner then watch the live data. In peticular, watch your ect, iac position, short term fuel trim and o2 sensors. Make sure they are operating normal. If something is out of range that might give you an idea as to what the issue is. If you have any questions feel free to ask. Also. Depending on the production date of your car you might have an obdII dlc that you can check data through. If you don't then it would not be smart to assume that because there's no light, there's no problem. I have a dtc 51 in my 1gs for a tps and it doesn't sent a hard dtc (cel). Might be worth it to try and pull codes to see if there are any present even though the light is off.

blkstealthpaid4

Oh yeah I am pulling codes with the scanner.The only code I have is that menacing 420 and 430 codes, and I have had that for the past 6 yrs.I have given up on repairing those codes as it is indicating the cats.Those are the only codes I have and it has nothing to do with this issue.I will see if the seafoam works.I also need to know where the IAC is located.I know the IAC usually looks just like the TPS and I already know where the TPS is located.This issue is just like the RX300.My wives RX300 has a common IAC motor issue where you have to sporay starting fluid on the IAC because it sticks.I just need to know where the IAC is located incase the seafoam do not work.

BobN54

As others posted, first step I would do is spray some cleaner into all of the little passages in the TB. Don't know if it transfers through to the Lexus, but this is a common problem in the Toyota Camry V6 where a tiny piece of carbon clogs up the idle air circuit.

mspearl95

Does it only do it when warm?

mb a leaking fuel injector bleeding down your fuel pressure after you shut it off.

blkstealthpaid4

Thank you seafome and brake booster hose.PROBLEM FIXED.

tonyfazt

sounds like a vacuum leak if you got to step on it for it to stay on