3.0 really high idle when cold, and no power

[Yanman]

I've done alot of searching on this, and alot of it has the engine being able to start but dies right away and/or idles rough.

Mine starts up just fine and purrs like a kitten but as the title says it idles real high around 1800 RPM, and if I don't let it warm up for at least 5 min or longer it has very low power. When it is warm, it idles at the recomended 800 RPMs and there is plenty of power, as far as a 3.0 goes.

The cures I have found stem from replacing the cold start injector, adjusting the idle screw, replacing the EGR valve, replacing wiring, and/or checking for vacuum leaks and replacing vacuum hoses.

So I guess first things first, what is the "normal" idle speed of a 3.0 when its cold? Is 1800 RPM OK? How high is too high? And why is there no power, besides it being a 3.slow?

Thanks

[ike]

Seems to be a fairly common issue. I know 88runnermikes was doing it but I don't know if he got it fixed. Hopefully thefatkid will chime in.

There are a ton of threads on yota tech about it.
http://www.yotatech.com/f116/3vze-fa...cation-110754/

[88RunnerMike]

Nope, my idle is still messed up, but not exactly the same symptoms. I haven't noticed a power issue, my main problem is that it's a PITA to start in the cold. And after it's warmed up (i.e. drive for 30+ minutes) it still idles at about 1200 RPM.

I found a troubleshooting guide in either the '89 or '90 FSM (the '88 one I have a PDF of from the NorCal TTORA site doesn't ever address the 3vze in the engine sections ) that seemed to point to some sensor as being a common culprit for idle issues. There's a test involving an ohm/volt meter and the ECU that I don't remember the specifics on...I've got the pages printed out at home I can pull out tonight.

[Yanman]

Yeah, I've ran into that too. I guess Toyota didn't let the writers of the FSM and other repair manuals (Chilton, etc.) know about the 3.0 until AFTER the books were published.

I too have scanned over the 2nd gen 4Runner FSM trying to find an answer, granted I have a few leads but I'm hoping that someone who knows what they are doing can give me more of a clue before I start replacing whats left of the original engine.

I did find an interesting post on a different forum, I think yotatech, but this guy found out some of his wiring was badly corroded and was causing his startup and idle problems.

[dwishart505]

i have had 3 3.slows in my life and all of them idle very high when cold. 1800 is higher then what i am used to, 12-1500 is normal from my experience.

when was the last time you ran some injector cleaner in your fuel? i started cycling a cleaner more often and it help with the cold starts. the cold start injector will function better and increase warm up time.

i am not sure on the power issue. when my 3.slows were cold the throttle response was terrible but not lacking power.

good luck!!!

[Yanman]

This issue has been around shortly after I replaced the engine, November of 2010.

I've ran a combo of injector cleaner (valvoline brand) and some 44K, in the same tank, back in March/Aprilish of this year, didn't help.

But thanks for the suggestion!

[Yanman]

Anyone have any other suggestions?

[thefatkid]

1800 seems a little high, but not too bad. You could try to replace the cold idle control valve and see what happens.

Old 3.0l have poor logic for cold starts and will always lack power.

Other then that, I'd need to see it

[Yanman]

Cool thanks. I'll try replacing the cold idle control valve. Please excuse what will be a newbie question, is that the same as the cold start injector? I'm looking for the control valve in the FSM and am having difficulty finding it under that name, unless I'm not looking in the right spot.

Do you have any after market parts stores you highly recomend? NAPA, Carquest? Or do you prefer to stay with Toyota OEM parts? If so, do you know a place I can get them at a discount instead of getting ripped off at the dealership?

[thefatkid]

That will be a dealer only part. It is located on the bottom of the throttle body and has 2 coolant hoses going in/out of it. The cold idle valve would be in the section with throttle body inspection/rebuild of the FSM.

You might want to ensure proper coolant flow though the valve before you replace it. If the valve is exposed to air (air bubble or something) it can change you high idle speed. Also, check you warm idle speed and make sure it is set to 700 rpm. Timing is also important but should not change it that much, I liked to run 10° on the 3.slow. You can back it down to 8° if you pinging or run higher grade fuel. If should not ping unless you milled the heads to raise compression.

One thing to remember, idle speed on this truck is controlled not by the ECU but mechanical devices. Now you could have a little influence from other electrical operation if they are not working 100%. Can you think of any other changes that you did when rebuilding the engine? Cleaning the intake?

There could be a chance that you have an air leak when cold that seals when hot. I would think that would create a cold start issue, not high idle.

[Yanman]

I appreciate your help and patience on this.

Originally Posted by thefatkid

That will be a dealer only part. It is located on the bottom of the throttle body and has 2 coolant hoses going in/out of it. The cold idle valve would be in the section with throttle body inspection/rebuild of the FSM.

So I'm going off what I see in the FSM, I don't have my rig in front of me to verify.

I think I see the part you are talking about in the FSM, I think the FSM has a different name for it, its calling it the "Throttle Valve"? It doesn't look like it can be replaced without replacing the entire Throttle Body on the 3.0. At least there is no mention of how it can be removed.

The part that can be removed and adjusted is the Throttle Position Sensor. I can remove that part, but I don't have the tools to adjust it.

Again I could be way off base here, and have misinterpreted.

Originally Posted by thefatkid

You might want to ensure proper coolant flow though the valve before you replace it. If the valve is exposed to air (air bubble or something) it can change you high idle speed. Also, check you warm idle speed and make sure it is set to 700 rpm. Timing is also important but should not change it that much, I liked to run 10° on the 3.slow. You can back it down to 8° if you pinging or run higher grade fuel. If should not ping unless you milled the heads to raise compression.

One thing to remember, idle speed on this truck is controlled not by the ECU but mechanical devices. Now you could have a little influence from other electrical operation if they are not working 100%. Can you think of any other changes that you did when rebuilding the engine? Cleaning the intake?

I got Jacob (ToyCrawlers) to help me with this engine job, and he did the setup. I don't remember where he set the timing, but I know he followed what the FSM recomended as far as warm idle speed, 800 RPMs.

We, or I pretty much cleaned every part of the intake, with the exception of the throttle body and air plenum.

I doubt this will have any bearing on this issue, but I went with headers instead of the OEM exhaust manifolds.

We also ditched the AC system.

Other than those changes it was pretty much a direct 3.0 long block replacement, along with replacing the entire cooling system.

Unless the place I got the long block from did something when they rebuilt the engine.

Originally Posted by thefatkid

There could be a chance that you have an air leak when cold that seals when hot. I would think that would create a cold start issue, not high idle.

I'll check to see if there is an air leak.

If you think that 1800 RPMs is not that high, and if you don't think it will hurt anything then I will probably let this go, for now.

I did a price check on a new throttle body from ToyotaPartSales.com and they go for $380. I tried to find just a cold idle valve, and it was not listed.

[mrdoug]

You might also want to check with Champion Toyota when you're price shopping. I picked up a few parts from them for better than expected prices.

http://www.tacomaterritory.com/forum...d.php?t=161867

[Yanman]

I think Champion and ToyotaPartsSales are one in the the same, regardless, I did check out Champion and they want the same for the throttle body.

But I will also try calling Shannon directly to see if the extra 5% is still on for TTORA members.

[Yanman]

Quick update on this, and same question to the more knowledgeable.

So I've been driving my rig around the last few days to get a better idea of the idle problem. I have not done anything to the rig other than turn down the idle a little after it has warmed up to between 700 and 800 RPMs.

The highest I've seen it idle after letting the truck sit over night is 2100 RPMs.

So same question as before, is this too high, and should I be saying "Holy Shit! I better get that fixed ASAP before something really expensive breaks?"

[thefatkid]

Over 2k rpm sustained idle is not correct. Now you might get an initial flair above 2k rpm but it should settle to 1500rpm or so.

[Yanman]

Thats what its doing, at first startup it shoots up around 2kish and then starts to settle down to 1500ish.

So sounds like its not a problem and its doing what its supposed to do.

Just me being paraniod and too used to my taco 3.4 and how it cold idles. Thanks for the help.

Good now I can spend money on a different part of that money pit. Like more toys!