ruff morning idle

[Skinny_Pedal]

every morning or when the truck is cold and i start it the rpm's drop down to about 300 and then stay steady at 500. eventually it warms up and stays at 1000rpm at idle. the truck didnt used to do this and now im curious to why it started to?

[BigMike]

Hey 86, next time it does that try wacking the TPS and see if that does anything... Its possible that it is *just* a *tad* off, and it is switching the idle circuit on and off....

...and if the idle circuit is reading off, then it will read how much air is coming in, and since the throttle plate is closed, its gonna idle really low.

Try that mang

[Skinny_Pedal]

thing is i usually have to give it a good rev to keep her alive at first. ill get nick to slap it

[Mike D]

Hey 86, next time it does that try wacking the TPS and see if that does anything... Its possible that it is *just* a *tad* off, and it is switching the idle circuit on and off....

...and if the idle circuit is reading off, then it will read how much air is coming in, and since the throttle plate is closed, its gonna idle really low.

Try that mang

well if it is off wouldn't the idle stay low and not advance to 1000

[Skinny_Pedal]

would this have anything to do with my timing?

[Mike D]

doesn't sund like it does cause the idle varies

[BigMike]

Hmmm well if it is realy varring, then this probably isnt the problem.

But I put a 22R-E together last month for a 87 4Runner, and their was no cold idle and the whole thing would shake badly. It would idle at 500 rpm even with the idle screw up almost all the way, and then once it was warm, it was up to around 1100 rpm. So Marlin told me to check the TPS, and sure enough, if I wack the TPS, it would jump into cold idle at 1200, then warm up and drop back to the normall 800.

The TPS has a seperate circuit for idle and if it is not touching the idle circuit, then the ecu doesnt think you are idling, and therefore will use other sensors, such as the air flow meter, to determine how much fuel/timing to use.

.........and if that's not the problem, have you ever opened up your air flow meter? and didnt reseal it correctly? Just a tad of moisture in that thing will screw it all up.

Hey, once its warmed up and running fine, how's the power feel? Normal?

[Skinny_Pedal]

that sounds like my truck when its cold. once it warms up it runs fine. actually i can just start driving and it runs fine. just the idle is all funky and the truck rattles like a bat out of hell

[Mike D]

last night I replaced the TPS on my bro's truck cause the comp was not getting a sig from the IDL terminal on the tps and it was idleing at 2000 now it is at 1200. We couldn't set the timing cause like bigmike said the comp thinks the engine is not at idleso the timing would never advance to 10-14 degrees. check your codes and see what you get