Up&Down

Anything new "rams" and "giantjoebot"?

Nothing here. Just a Taco that still idles rough at op temp.

I'm thinking of breaking down and taking it to the dealership down the road.

I took it to a standard mechanic and he was at a loss. I don't think he ran a whole lot of diagnostics but mentioned the fan clutch. I has a slight wobble and lope sound to it but it works fine and keeps the truck at op temp.

I still love the truck. I put a lot into the suspension recently so it rides great. Just don't let it sit at a stop light.

Do y'all think it could be the IACV?

Thanks all.

giantjoebot

Sorry, I haven't had time to mess with my truck recently. Been taking a break. I put new shocks on, and I don't feel it vibrate like I use to, but Its still there. I don't know when I'll have time to work on it. I work on computers in my spare time, and have been kind of swamped lately. I really think mines the evap or the transmission (rear engine) mount. The mount is cheap, and I have to change the oil soon, probably do them at the same time. If you don't hear from me that probably means it didn't help, but I'll try and post and let you know how it goes.

massina218

I had a problem similiar to this on my 97 4runner. Shook like the engine was going to fly apart and had no power, until you got the rpm above 2 thousand. Turned out to be a "coolant temperature sensor". Screws into the top of the motor, where the radiator hose returns to the engine. Basically this device acts as a variable resistor, and supplies the computer with a value reference temperature (acts like an automatic choke, and changes the mixture). Might be worth checking, the part was around $50 I think, on partsgeek.com. Hope that helps.

giantjoebot

I replaced my transmission mount, but it still vibrates. But on the upside its shifting a lot better, and I have a smoother ride. Only $8 for the mount at Kragens, O'Reilly. For $8 its worth a try. It wasn't that hard to put on either. Had to grind out one of the holes because it was a little off, and couldn't figure out what the 30mm bolt was for until I asked at the part store. Don't quote me on this, but it seems to be a safety measure in case the mount breaks. So there should be a gap, and only loosen it if its touching. Other than that, jack, wood, 12 bolts, and your done. Have some WD40 and a breaker bar on hand.

pendrag

Any updates from anyone in the thread?

Up&Down

I don't have any significant updates.

The new change I've found is when I'm sitting at idle at a stop light and my truck is rattling my teeth out of my gums I can turn on the AC and the vibration stops cold. It's amazing. It's like the extra load of the AC compressor kicking on makes the truck stop vibrating.

What could cause this?

Does this give any insight to the experts our there about what this whole rough idle/vibration could be sourced from?

I still need to check the resistance readings for the IACV.

Does anyone think the temp coolant sensor could be the culprit?

giantjoebot

I know this might sound stupid, but for me, right now, I think the problem is air trapped in the coolant. When I did work to my coolant system I didn't get all the air out, and I don't think that I turned on the heater when I burped it. I noticed that it vibrated more when it was cold outside, and its because I was turning the heater on and the air trapped inside was coming out of the heater core, I think. Anyways, thats my theory right now. I ordered a special spill free funnel off amazon thats suppose to make the job a lot easier. Let you know how it goes after the funnel arrives.

http://www.amazon.com/gp/product/B00..._ya_os_product

When I was reading up on the coolant thing today I could have sworn I saw something about it getting better when turning the the AC on, but I don't remember where, and now I can't find it. My truck doesn't have AC, so I can't try that.

pendrag

What the heck, burp your coolant and tell us how that went for you. I can't believe how many people I've seen posting about this issue with no definite solution (despite tons of money being thrown at suggested causes).

rideexileex

iTrader: (1)

Does the vibration stop instantly? Or only once the air actually cools to "AC cold"?

Do the RPM's change as well once you turn the AC? My RPM's will go up a little bit due to the increased load.

txt4r

I have the same vibration issue as UP&DOWN described. It has been like this for two or three years. Still look for a fix.

Up&Down, maybe we should ask people at http://www.toyota-4runner.org/3rd-gen-t4rs/

giantjoebot

Sorry if this is another stupid post. Burping the coolant didn't work. I was watching Eric the car guy, and on one of his videos he said the first thing to check with a rough idle is air in the coolant. Makes sense with my 22re since the idle air control valve uses the coolant temp to open and close, and its possibly the highest point in the cooling system.

So I was working on it, and long story short, I disconnected the throttle position sensor, and my idle smoothed out, and the vibration seemed to stop. Check Engine light came on, but it seemed to run better with it disconnected.

So I'm thinking I got a bad TPS, but I was reading in the fsm that the TPS needs to be adjusted, by turning clockwise. So I don't know if I have a bad TPS, or if its just out of adjustment. Seems like my fuel to air ratio is off due to a bad reading from the TPS, and the computer, sorry I know thats not the right term but I can't remember, is constantly trying to adjust.

So tomorrow I'm going to try and adjust the TPS, and if that doesn't work I'm going to buy one from the dealership for $80 after a 20% off online coupon.

Up&Down

Sorry for the delay guys. Work has been busy. Out of town a lot.

Yes rideexileex, the vibration stops immediately upon turning on the AC. Like yours, my rpms bump up too thus eliminating the rough idle.

Has anyone done the ohms resistance test on the IACV? That is my next stab at this. If the readings are off I'll see about replacing it. It ain't cheap.

I also heard a rumor about adjusting the IACV. Anyone?

Up&Down

giantjoebot, what's up with your TPS reports?

Where is the TPS located?

Would my 1995 2.4L have one?

Up&Down

Anything new out there?

JCFL

I've been lurking for some time and want to say that my 2000 Taco 2.7L 4x4 is having the same issue. Rough idle when in drive and reverse. Not jaw-chattering rattling but still rattling that stops somewhat when I turn on the A/C or put it in neutral. I think that the IACV (IACV is the idle air control valve ) might be the next thing to check as you asked about earlier. I have exhausted searching the net and keep coming back to the IACV. Anyone tried this yet?

It would be great if someone actually came through on this issue!

JCFL

.....

Up&Down

I'm sorry to hear another is having the same issue with no solution.

I still haven't taken the time to check the resistance values. It will include taking components off and it's getting cold here in Maine and I have no garage to work in so it will likely have to wait for another six months.

The price of a new IACV ain't small. So definitely make sure it's the culprit before replacing it.

There is still the coolant temp sensor and throttle control sensor to check as well.

My gas mileage is still what it should be so that is good. How about you guys?

All: don't let this thread go dead. I'll keep everyone informed with what I do in the future. It seems this thread when complete with solution could be very useful to lots of folks in the future.

The Law Of Averages says we have to be getting close to a solution soon right? Hahaha!

pendrag

I have basically the same issue, I think. I just noticed today while idling roughly at a stop light, that if I locked the doors, I got a momentary spike in the rumbling immediately after the locks engaged. I could replicate it multiple time, just by actuating the locks. If I gave the truck a little gas to rev up the RPMs a few hundred, the vibration goes away (as usual) and the locks wouldn't produce that increase in the vibration.

Does this suggest possibly some sort of electrical issue behind the whole thing? Perhaps something to do with a ground, or the alternator not putting out enough juice? I had a new rectifier and regulator put on the alternator on the 2WD truck, but the alternator hasn't had problems on the 4WD. (Both trucks have the vibration issue.)

giantjoebot

Well I've narrowed my down, at least I think I have. I had a couple bad fuel injectors, and a couple of the clips were bad. If you try it, send your injectors to witch hunter like the guys on here suggest. I went with a local guy, and wish I had used witch hunter. Anyways, I didn't get one of the injectors in right before my trip, and it leaked. I will verify if that was actually the problem when I get home.

But check the electrical clips going to your injectors first. I've heard a lot of people have had problems with those.

Up&Down

I haven't thought of bad fuel injectors.

I'm not sure what you mean when you say electrical clips.

Pendrag: I'm not sure it would be an electrical component. My guess is the electrical locks put a small load on the electrical system transferring it to the alternator which thus transfers the load to the engine which brings the RPMs down a bit causing the spike in the rough idle/vibration.

I honestly don't think I'll be checking the IACV before next spring but when I do I'll let you all know what the scene is.

Good luck.