Initial startup problem.

[LethalInjection]

Ok, this one has me stumped. When I first start my car I can drive it for about a minute or so then it starts missing and running generally crappy. If you put it on the mat, it will go away, but as soon as you go down to part throttle or light throttle it's back. It will run this way and be annoying for about 2 minutes or so and then it's fine again for good until you shut it off again. This is annoying the crap out of me because unless I let it sit there and run for several minutes on startup it runs like a POS for that small time span. I'm thinking it has something to do with a sensor and is affected in startup loop. Anybody got any ideas?

 

[toyman]

Idle air control (IAC) valve maybe sticking or perhaps the throttle position senor (TPS) is/has gone south. Those are my first guesses for the start up issues. Of course it could be may other things. When was the MAF last cleaned or the plugs, wires, cap and rotor changed? Only you know the anwsers to these questions

 

[LethalInjection]

MAF cleaned three or four weeks ago with Q tip and rubbing alcohol. It's more of a bad miss like a vacuum leak or ignition problem. It occurs driving down the road so I don't think it's the IAC. I will check the cap, plugs, and wires, but it runs perfectly after the 2 or so minutes of crap running. It happens at the same time intervals each time. About a minute after I start the car it sets in, misses and runs horribly for about 2 minutes, and then clears up. It does the same on cold start or I can turn the car off hot, let it sit for a couple minutes, and it will do it again. It's got me confused as heck.

 

[red95gtconvert]

I feel you pain because my car does the same exact thing just like you desribe. I hope you figure it out, I have tried everything with no luck.

 

[Labora]

Coolant temp sensor, when they get old they do not read correctly until the coolant warms up a good bit.

My car use to pop/bang/stall until it got warmed when I replaced this sensor it worked fine while COLD. (would only happen first start of day in the morn usually)

 

[LethalInjection]

Coolant temp sensor, when they get old they do not read correctly until the coolant warms up a good bit.

My car use to pop/bang/stall until it got warmed when I replaced this sensor it worked fine while COLD. (would only happen first start of day in the morn usually)

See I was thinking something like that too. Something that had to do with the engine warming up, but if I shut it off at the gas station and restart it, it does the same darn thing with the engine already at operating temperature. I was going to meet my gf for lunch today, and I let the car idle for 3 minutes after I started it before I drove off. It worked fine. I wish I knew what all was going on with the sensors and computer that changes from 0 to 1 minute and then from 1 minute to 2 minutes later. It's like at exactly those intervals. Problem occurs about a minute after startup and persists for another 2 or so before going away. The same EVERY time. What the crap is goin on!? haha

 

[LethalInjection]

Been thinking. I have my EGR plugged off, but still have the electical side of it plugged in. However I haven't taken it off to push the plunger in halfway or whatever. Could this for some reason have started to cause this? I know there's some funky EGR stuff goin on during startup.

 

[Labora]

FYI my Coolant Temp sensor was doing this @ around 65k miles on the clock.... If yours is stock I'd still switch it out.