High idle? Stumped.

[psea17]

I understand this is an old thread but i figured for the benefit of the next person that is searching for a solution, I'd add my insights here.

I had done a valve cover gasket job and replaced the air boot due to a tear. While I had the throttle body off I cleaned it along with IACV. I replaced the PCV as well. When I got it back together, my idle was high. It's been that way for about a year. Usually when the truck would warm up after driving it around, the idle would return to the normal range. I tried resetting the ECU multiple times. I replaced the MAF. Cleaned the MAF later. Replaced the air K&N air filter. Removed the throttle body and IAC again. Everything looked good. I checked the vacuum hoses looking for leaks. Nothing there either.

Today, i installed a new fuel filter and VOILA! No more high idle. Note I didn't even remove the battery ground to do this. I just unplugged the connection to the fuel pump, ran the fuel line dry (wouldn't start actually) and replaced the filter. Happy to report no high idle. If the problem should return, I will report back.

Hope this helps someone down the road.

 

[Gull81]

I understand this is an old thread but i figured for the benefit of the next person that is searching for a solution, I'd add my insights here.

I had done a valve cover gasket job and replaced the air boot due to a tear. While I had the throttle body off I cleaned it along with IACV. I replaced the PCV as well. When I got it back together, my idle was high. It's been that way for about a year. Usually when the truck would warm up after driving it around, the idle would return to the normal range. I tried resetting the ECU multiple times. I replaced the MAF. Cleaned the MAF later. Replaced the air K&N air filter. Removed the throttle body and IAC again. Everything looked good. I checked the vacuum hoses looking for leaks. Nothing there either.

Today, i installed a new fuel filter and VOILA! No more high idle. Note I didn't even remove the battery ground to do this. I just unplugged the connection to the fuel pump, ran the fuel line dry (wouldn't start actually) and replaced the filter. Happy to report no high idle. If the problem should return, I will report back.

Hope this helps someone down the road.

Do you, or anyone, have theories on why this would affect the idle?

 

[spartacus]

I can understand rough idle due to clogged filter. High idle is normally iac , vacuum leak bad maf etc.

 

[19963.4lsr5]

Do you, or anyone, have theories on why this would affect the idle?

It makes no sense to me.


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[Gull81]

It makes no sense to me.


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The only thing I could think of is that it would only cause high idle if it is on the return portion of the fuel system. If the filter is after the fuel rail and therefore 'backs up' the fuel further pressurizing the fuel rail.

I don't think that is the case though.

Maybe something weird with the ECU and fuel pressure regulation system? Maybe the fuel pressure is gauged somewhere other than the fuel rail and the car compensates by increasing fuel pressure?

I have no idea about the fuel delivery system on these cars so my ideas are probably completely off.

 

[Travis_Boylen]

Same issue different result

I had the same high idling issue after new fuel injectors, a new water pump and a new timing belt. Unfortunately I havent been able to solve it yet and now it overheated and wont start.

2000 4runner has 235k miles on it. 3 months ago I figured out i needed to replace a fuel injector(thats what the codes said and it wasnt my first one). I had another vehicle at the time so I didn't really need to drive it and after the shop initially told me nothing was wrong with the vehicle, I brought it home and the same symptoms and codes would keep popping up while driving on short trips around town. After some of the short trips i also noticed that it was leaking coolant around the water pump area and i would have to refill it. Again, It has 235k miles on it and based on previous owner messaging i figured it was time for a new water pump and of course timing belt so I finally broke down and took it back to the shop about 2 weeks ago and that's where my troubles really began.

After picking it up.
1. It had a bad vacuum hose and died on the road the same day i picked it up. Had the vehicle towed back to the shop and they corrected the issue.
2. About 3 days and 50 miles later the vehicle started to idle at 2500 RPM while in park and about 1000 rpm in drive and stopped. So i took it back to the shop, they checked the rest of the vacuum lines. Replaced one but it would still idle at 1700 RPM like everyone else in this thread.
3. Called the shop back yesterday, they said their next step would be to replace the Throttle Position Sensor and that i could probably do that myself and save some $$. So I had planned to try that out this weekend.
4. Tonight on my trip home of about 20 miles the vehicle started getting above temp, about a mile from home the dash lights lit up and it died on the exit ramp. There is coolant all over the front of the engine but not on top for the most part, there is coolant in the reservoir, the fan blade has several pieces broken on it but I don't see that it was hitting anything and didn't hear anything, I also have no electrical power even though its a brand new battery. I was able to tug it home but now its sitting in the driveway and any real testing for this issue is probably past my skill level.

Any help or advice is greatly appreciated.

Now what do I do??

 

[spartacus]

I had the same high idling issue after new fuel injectors, a new water pump and a new timing belt. Unfortunately I havent been able to solve it yet and now it overheated and wont start.

2000 4runner has 235k miles on it. 3 months ago I figured out i needed to replace a fuel injector(thats what the codes said and it wasnt my first one). I had another vehicle at the time so I didn't really need to drive it and after the shop initially told me nothing was wrong with the vehicle, I brought it home and the same symptoms and codes would keep popping up while driving on short trips around town. After some of the short trips i also noticed that it was leaking coolant around the water pump area and i would have to refill it. Again, It has 235k miles on it and based on previous owner messaging i figured it was time for a new water pump and of course timing belt so I finally broke down and took it back to the shop about 2 weeks ago and that's where my troubles really began.

After picking it up.
1. It had a bad vacuum hose and died on the road the same day i picked it up. Had the vehicle towed back to the shop and they corrected the issue.
2. About 3 days and 50 miles later the vehicle started to idle at 2500 RPM while in park and about 1000 rpm in drive and stopped. So i took it back to the shop, they checked the rest of the vacuum lines. Replaced one but it would still idle at 1700 RPM like everyone else in this thread.
3. Called the shop back yesterday, they said their next step would be to replace the Throttle Position Sensor and that i could probably do that myself and save some $$. So I had planned to try that out this weekend.
4. Tonight on my trip home of about 20 miles the vehicle started getting above temp, about a mile from home the dash lights lit up and it died on the exit ramp. There is coolant all over the front of the engine but not on top for the most part, there is coolant in the reservoir, the fan blade has several pieces broken on it but I don't see that it was hitting anything and didn't hear anything, I also have no electrical power even though its a brand new battery. I was able to tug it home but now its sitting in the driveway and any real testing for this issue is probably past my skill level.

Any help or advice is greatly appreciated.

Now what do I do??

Firstly the shop did the work, you should hold their feet to the fire. They did the water pump timing belt job and that's when your problems started. They might blame you if you work on the truck now. If you want to trouble shoot it now on your own, start by checking the fuses the, sta fuse, Ign fuse, and others.Try to pinpoint where the coolant leak is, you can fill it with water temporarily but would have to drain and refill with red or pink coolant. Once your truck is running then you can trouble shoot the high idle.

 

[Travis_Boylen]

Thanks Spartacus. I agree except I was a bit concerned with the fan blade and how that could happen with all this as some of the parts are still laying around the engine bay. I also want to make sure I have all the ammo I need when I go in there...

 

[spartacus]

Thanks Spartacus. I agree except I was a bit concerned with the fan blade and how that could happen with all this as some of the parts are still laying around the engine bay. I also want to make sure I have all the ammo I need when I go in there...

They obviously did not install or properly tightened the bolts for the fan pulley brackets. Who knows if they did the rest of the job right!

 

[Travis_Boylen]

Yep now that it's light out I put some antifreeze in it, 9 degrees right now so water was out. Antifreeze dripping all over the bottom of radiator. When I tried to find where it was coming from I found at least 3 bolts on the fan blade that were loose. So am assuming the blade hit the guard and the radiator and that's where the fluid is coming from.
Last question before I take it in. I got it to turn over but but the jump box I have didn't last long enough to to start it. Do I try and start it or could I damage more? Like I said it's cold here so getting hot isn't a concern, now that I know what's going on. But I'm still worried about any damage this all caused last night.

 

[Pyral]

I don't think starting it would damage it, but I wouldn't do anything because it's the shops problem. They should warranty their work, and I wouldn't attempt anything that could give them an out.

If it's leaking that much coolant you can't rely on the temperature gauge. Air doesn't warm up like coolant, so having air will give you a false sense of security. Even if it's cold.

 

[spartacus]

Yep now that it's light out I put some antifreeze in it, 9 degrees right now so water was out. Antifreeze dripping all over the bottom of radiator. When I tried to find where it was coming from I found at least 3 bolts on the fan blade that were loose. So am assuming the blade hit the guard and the radiator and that's where the fluid is coming from.
Last question before I take it in. I got it to turn over but but the jump box I have didn't last long enough to to start it. Do I try and start it or could I damage more? Like I said it's cold here so getting hot isn't a concern, now that I know what's going on. But I'm still worried about any damage this all caused last night.

Why fire up the truck? let the shop make it right.

 

[Travis_Boylen]

Why fire up the truck? let the shop make it right.

Thanks and Agreed, but it was saturday, the shop was closed, and my paranoia was getting the best of me. After I calmed down I realized that even if its not overheating, the fan blades loose and i don't want to create more damage.

Called shop back today. Service manager was out but the guy I talked to started to spin me some bull** about the fact that it was idling high could have caused the blades to come loose. Told him that that was a line of ** and am waiting for the manager to call me back. I have had good luck with this shop over the years but on the job the more they talk the less I believe anything they say

Anybody know if there is something with the timing belt install that could have caused the high idle? I have seen a few other threads on this topic suggesting that could be the issue but none of those resulted in that actually being the issue.

 

[19963.4lsr5]

Thanks and Agreed, but it was saturday, the shop was closed, and my paranoia was getting the best of me. After I calmed down I realized that even if its not overheating, the fan blades loose and i don't want to create more damage.

Called shop back today. Service manager was out but the guy I talked to started to spin me some bull** about the fact that it was idling high could have caused the blades to come loose. Told him that that was a line of ** and am waiting for the manager to call me back. I have had good luck with this shop over the years but on the job the more they talk the less I believe anything they say

Anybody know if there is something with the timing belt install that could have caused the high idle? I have seen a few other threads on this topic suggesting that could be the issue but none of those resulted in that actually being the issue.

I read that the shop did hoses and want to replace the TPS next.

Have they ever replaced or removed and cleaned the IAC?

There are also vacuum lines that go from the IAC to the intake manifold at each injector to help atomize the fuel at low RPMs. Look at the back of the intake under the throttle body. My hoses were old and hard when I rebuilt the engine and replaced everything associated with that little system.


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[spartacus]

Thanks and Agreed, but it was saturday, the shop was closed, and my paranoia was getting the best of me. After I calmed down I realized that even if its not overheating, the fan blades loose and i don't want to create more damage.

Called shop back today. Service manager was out but the guy I talked to started to spin me some bull** about the fact that it was idling high could have caused the blades to come loose. Told him that that was a line of ** and am waiting for the manager to call me back. I have had good luck with this shop over the years but on the job the more they talk the less I believe anything they say

Anybody know if there is something with the timing belt install that could have caused the high idlek? I have seen a few other threads on this topic suggesting that could be the issue but none of those resulted in that actually being the issue.

There are lines that go to the the throttle body that some have attached incorrectly resulting in high idle. You had indicated that they fixed one of the vacuum lines. Did you mean it was cracked or it wasn't hooked up right. High idle most commonly is vacuum leak, lines cracked or not hooked up correctly, carbon buildup in the throttle body and iac. dirty maf etc. As far as timing you can pull the top cover and check that the timing marks line up on the cam and crank pulleys. I would ask which mechanic worked on your truck and talked to him. The statement that the bolts came loose because of high idle makes me believe that the shop is now in damage control and would try to make you pay instead of owning up to it. I would ask for my money back minus the parts they put on your truck and take it to a different shop or Diy. If they don't make it right then I would file a small claim against them and let it take its course while I get the truck road worthy.

 

[Travis_Boylen]

I read that the shop did hoses and want to replace the TPS next.

Have they ever replaced or removed and cleaned the IAC?

There are also vacuum lines that go from the IAC to the intake manifold at each injector to help atomize the fuel at low RPMs. Look at the back of the intake under the throttle body. My hoses were old and hard when I rebuilt the engine and replaced everything associated with that little system.


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Not yet, didn't get a chance to before everything else hit the fan. Ill make sure the IAC ends up on their list though.

 

[Travis_Boylen]

There are lines that go to the the throttle body that some have attached incorrectly resulting in high idle. You had indicated that they fixed one of the vacuum lines. Did you mean it was cracked or it wasn't hooked up right. High idle most commonly is vacuum leak, lines cracked or not hooked up correctly, carbon buildup in the throttle body and iac. dirty maf etc. As far as timing you can pull the top cover and check that the timing marks line up on the cam and crank pulleys. I would ask which mechanic worked on your truck and talked to him. The statement that the bolts came loose because of high idle makes me believe that the shop is now in damage control and would try to make you pay instead of owning up to it. I would ask for my money back minus the parts they put on your truck and take it to a different shop or Diy. If they don't make it right then I would file a small claim against them and let it take its course while I get the truck road worthy.

The first time it died and i had to have it towed it was a cracked an rotted hose. I could actually hear it when we got it off the road and was able to get it started. The second time they didn't say if the hoses were on wrong or if they just replaced one but I was on the understanding they had replaced another hose with a small leak.

My guess is that i was talking to the mechanic today(and he's doing his own damage control) although he didn't mention what he did and i didnt think to ask at that point.

Ill give the service manager a chance to make it right but definitely wanted to be aware of any other information i needed when i spoke with him.

 

[19963.4lsr5]

Not yet, didn't get a chance to before everything else hit the fan. Ill make sure the IAC ends up on their list though.

You need to check those air assist vacuum lines that go from the bottom of the iac to the intake manifold.


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[Travis_Boylen]

So its better but not done. After a lengthy conversation with the shop they agreed to replace the radiator and the fan. Not sure if i should have, but i did agree to pay for the labor, not all the bolts on the fan were loose and i didnt want to argure myself out of the parts offer(I did notice that when i inspected it as well).

Prior to full replacement, the shop said it was not idling high at that point. After full install though, it started idling high once it got wam. They did a full smoke test on all hoses and checked and rechecked all of them. Checked out the TPS again and said they dont think thats the issue(they only briefly looked at it last time). They also checked out the control or sensor that checks for coolant temp and ruled that out. Blanking at the moment on the name of this one..

The only IAC valve they could get was $300 so they gave me the option to get one myself and this is where the real question comes in. Anyone have any luck long term with aftermarket IAC valves or have a suggestion on where to get one at a decent price that works and ships relatively fast? Ive been surviving but having 3 drivers and only 1 vehicle on the weekends is getting old

 

[Travis_Boylen]

Fixed(for the most part)

Got the IAC(carparts.com had the best price and quickest shipt times i could find) to the shop tuesday and picked it up Wednesday finally. Took 2 weeks and some back and forth discussion with the shop but she seems to be running ok