Low idle??

I've done a little research on here but I was wanting some more feed back. I own a 2002 taco with the 2.7L engine. I have 173,500 miles on the engine. I was wondering if my idle was normal or if it was a bit low. When I pull up to a stop light my idle will be right at 750 rpms or a tad under, then if I sit there for awhile waiting for the light to change it moves down to 650 rpms. The tach does not bounce around at all it stays steady.

I just wanted to see what some of the other 2.7L owners are experiencing for idle. Thanks

 

My 2.4 does the exact same. I have remanufactured fuel injectors that I plan to change soon (2 weeks). It didn't start to do that (low idle) until I started to mess w/ the fuel system. I recently changed fuel pump and fuel filter. May have sent debris down stream to fuel injector filters, or may have gotten by filter and messing w/fuel pattern. Fuel filter was the original factory w/ 192k miles on it. Dirty black soot poured out of filter when I drained it. That fuel filter REALLY could have been better located! And the crank shaft sensor too.

 

Your lucky, my 01 2.7 4x4 lopes when I pull up to stop light. 800-1500 rpms every 2 seconds. People look at me like the WTF is he doing. Cant seem to figure her out.Been searching and reading for two weeks now.

 

Have you checked your IAC? It's under your throttle body.

 

http://www.tacomaworld.com/forum/technical-chat/189650-2-7-stick-stalls-when-cold.html

Interesting thread...

 

I have changed the following.

IACV- OEM
Rear 02-OEM
Front 02-OEM
MAF sensor-OEM
TPS sensor-OEM
ECT sensor-AutoZone

cleaned the throttle body and all connectors.

I read the post and link above this. Mine starts fine, cold or hot, runs like a champ, gets 20 MPG and no other issues. Idle just surges from 1400-2000. all day.

 

My hot idle is smooth and steady, at around 700 rpm (2.7 with AT).

 

My hot idle hovers around 600-700. Its a little rough but far from stalling.

 

My 2004 2.7 does the same thing. It idles smooth at about 750 at a stop light then drops down to just about 500 rpm and idles rough. it's bad enough to where it almost won't idle across a parking lot in 1st gear without shuddering. I have no idea what causes it but it seems many of them do it.

 

Ive been chasing the same demon for months now. Ive changed just about everything I can think of and the low idle is still there

 

My 95 2.7 does the same thing, what I've noticed though, see if ya'lls does the same thing. Coming to a red light, AC off, put the transmission in neutral, I go ahead and coast all the way to the light idling, it will idle at about 650 to 700 according to the tach. As soon as I come to a COMPLETE stop, the tach drops to 500 rpm, it'll do this everytime, I can actually feel the motor drop in rpms so I know for sure it's happening.
The other strange thing is I can hook up my scanner and it reads right at the rpm the manual calls for which is 750 at idle with AC off. I can tell it's (the scanner) is reading high all through the gears when driving but still shows the correct rpm the motor is suppose to be doing at idle, even though I can feel the rpm is to low, I think the tach is reading correctly not the scanner.
I want to hook up another scanner and see if it's shows the same info as my scanner, if it is, then the only thing I can come up with is the ECM is getting bad info on the rpm side of the sensors. Don't know,,,, the motor idles very smooth either way.

 

I figure that with mine the previous owner (my dad) who never drove the truck hard at all and was always lugging it probably caused it to load up slightly. I ran a tank with Seafoam through it on the 500 mile drive home after I went to pick it up. That drive and the Seafoam seemed to clear out some of the cobwebs.

I got back and drove it around for a couple of weeks. Then I went and filled it with ethanol free gas and dumped a bottle of Techron in it about a week ago. Every other day or so I run it up to 4000-4500 rpm and generally shift it at 2500 to 3000. Tonight when I got home my idle was steady but it wasn't as smooth as it should be. The idle still drops intermittently when I sit at a stop light but it seems to be getting better.

My personal opinion is that if you don't run these things the way they were designed to run they probably get "stuck up" It was that way back in the old days with carbs and although these new engines have a computer to manage everything that doesn't mean the computer and all the various sensors still work perfect 100,000 miles down the road. Back when carbs were used with no computers they told you to take it out and beat on it once in a while to clear all the junk out. That isn't really the case these days with new computer controlled engines but to a certain extent I think it could be.

I'll wait and see if what I'm doing actually cures this fluctuating idle problem but so far I'm seeing a noticeable improvement even though it is not fixed entirely. It may take another treatment of Techron and some more revving if I am on the right track. If this doesn't do it I'll be checking the valves for proper adjustment. The funny thing is I haven't found anything anywhere that says the 2.7 requires periodic valve adjustment but valves out of adjustment could definitely cause this problem.