Idle feels low and sometimes drops?

[runrunner]

In gear my 99' V6 idles at the 600 rpm mark, at times it will drop to around 550 or so. In park I think its around 700 - 800. I searched around and it sounds like this is normal?

Today while waiting at a light the idle dropped to around 500 or a little lower, than went back up. It was enough to make me feel it. It felt like an electric fan or AC compressor kicked on, but we dont have e-fans and the defrost/AC was off.

Anything else that would cause the RPM's to drop like that? Everything was off and I didnt touch anything electrical.

I've also read that you cannot adjust the idle on these machines, its all computer based.

The following have been cleaned: MAF (dealer), IAC, T-body (both removed and cleaned), fuel injection cleaner ran through tank
The following have been replaced: plugs (denso), wires, fuel filter, PCV

Any suggestions? Thought about having a real fuel injection cleaning service done on it. Oh, and no codes.

 

[jsmarine]

hmmm, I might check vacuum lines for a leak. Also if you have a scan tool, plug it in to under the dash and see if anything comes up. I'm not an expert in OBD2 but maybe it has stored codes that are not triggering the CEL

EDIT: sorry , just saw the last part of your post about no codes, did you check that, or just assume since no CEL?

 

[runrunner]

EDIT: sorry , just saw the last part of your post about no codes, did you check that, or just assume since no CEL?

When I had it at the dealer for the warm hard start issue they cleaned the MAF and checked for stored codes and didnt find any.

 

[bigtimeweb]

My second gen did that with a head gasket leak

 

[brian2sun]

It's probably the coolant temp sensor which is ~ $15-30 (aftermarket - OEM) or the TPS (~ $45-100) and both are easy to replace yourself. I would test the TPS first and if it's good I'd probably just swap out the coolant temp sensor with a cheapo to see if it makes a difference.

Besides the idle fluctuations that seem to be sorta random, your idle #s are totally right - 7-800 in P and 550-600 in D or R. It should idle around 12-1400 after a cold start and take about 3-5 minutes to go to 7-800.

 

[ChildrenOfBodom]

In gear my 99' V6 idles at the 600 rpm mark, at times it will drop to around 550 or so. In park I think its around 700 - 800. I searched around and it sounds like this is normal?

Today while waiting at a light the idle dropped to around 500 or a little lower, than went back up. It was enough to make me feel it. It felt like an electric fan or AC compressor kicked on, but we don't have e-fans and the defrost/AC was off.

In all honesty, that sounds perfectly normal. Mine does that all the time... It's always done it. My mom's '95 Toyota Previa does it too. It's some sort of accessory kicking in... just like when you turn your wheels, the power steering pump makes your rpm rise a tad... I'm sure you know without me saying so. it happens to me all the time... I wouldn't be worried. My '99 4Runner is the 4 cyl too, so the idle isn't near as smooth as a V6, but I notice a difference in the idle and RPM when it happens.

 

[jjja4]

that just happened to mine too. i also had a sticky gas pedal. we took it to the toyota dealer a few days ago and they cleaned out the injectors, throttle body, and some other things. it works almost better than when we first got it, it runs great. it was only about $500 and a quick fix.

 

[brian2sun]

In all honesty, that sounds perfectly normal. Mine does that all the time... It's always done it. My mom's '95 Toyota Previa does it too. It's some sort of accessory kicking in... just like when you turn your wheels, the power steering pump makes your rpm rise a tad... I'm sure you know without me saying so. it happens to me all the time... I wouldn't be worried. My '99 4Runner is the 4 cyl too, so the idle isn't near as smooth as a V6, but I notice a difference in the idle and RPM when it happens.

Yeah, it could be a normal 4 banger thing.

 

[runrunner]

I dont know if it makes any difference but I dont believe I noticed it before I removed and cleaned the T-body and IAC.

Also, I've only noticed it once. It didnt do it at all this morning on the way home.

Is there any accesories that could kick on at random? Again, it reminded me of when an E-fan kicks on or AC compressor. It dropped idle for a second and then recovered back to normal.

I watched the idle when I put it in park too and it was at just a tad over 700, maybe 750.