Idle Issues - Exhaustive and Comprehensive!
08-24-2010, 08:12 PM
#41
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1990 4Runner, 3.0, (was auto)
It runs fine like it should.
Situation: When I step on the gas when it's warmed up, rpm drops and motor sounds like it would stall then rpm quickly jumps up. What would cause this? Idle is a little low 600-700 when warm but that could be fixed. It's just that when at a full stop and I put in neutral then step on the gas the rpm is not responsive like it should be....
Help please.
It runs fine like it should.
Situation: When I step on the gas when it's warmed up, rpm drops and motor sounds like it would stall then rpm quickly jumps up. What would cause this? Idle is a little low 600-700 when warm but that could be fixed. It's just that when at a full stop and I put in neutral then step on the gas the rpm is not responsive like it should be....
Help please.
08-30-2010, 07:04 PM
#43
so what have you done so far to fix this? Replaced anything? Tune up? plugs? We can only speculate as to what your problem could be as this thread was designed to be an avenue of what to go through to fix problems as opposed to "why does my yota idle like pooh" thread. Give us some info and start working on it. We have all started with something like the gas mileage stinks so i replaced the plugs, or my truck will not idle so the tps was replaced and fixed it. most of the problems i have encountered and how i have addressed them have been outlined in this thread.
Steps such as check plugs "spark"
Check air "vaccum" leaks AFM
TPS, O2 sensors things like that
Get out to the garage and start checking stuff out as opposed to my truck idles like crap fix it! thread replies. We all learned some how and through the forums it will always be read, research, and go out and try it will be your answer. Then and only then will you come back with some info that we can help you with.
Sorry if it sounds harsh but seriously go out to the garage and pull the plugs and look at them. If they look one way then this is the base problem. If they look another then this is the problem type of approach will get you further then what you have asked so far.
I was clueless when i started on my yota at the age of seventeen but learned how to ask the right questions after doing some home work to get the right answers.
Steps such as check plugs "spark"
Check air "vaccum" leaks AFM
TPS, O2 sensors things like that
Get out to the garage and start checking stuff out as opposed to my truck idles like crap fix it! thread replies. We all learned some how and through the forums it will always be read, research, and go out and try it will be your answer. Then and only then will you come back with some info that we can help you with.
Sorry if it sounds harsh but seriously go out to the garage and pull the plugs and look at them. If they look one way then this is the base problem. If they look another then this is the problem type of approach will get you further then what you have asked so far.
I was clueless when i started on my yota at the age of seventeen but learned how to ask the right questions after doing some home work to get the right answers.
Last edited by mightymouse; 08-30-2010 at 07:11 PM.
09-28-2010, 05:06 PM
#44
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I've got an idle problem on my 94' 3.0. when it's cold it will idle at 1000 rpm and it's pretty smooth. when it's warm it will idle at 500-700 rpm and it will surge at 1500 rpm when i hold it steady. i just eliminated my egr, changed the throttle position sensor, and replaced a destroyed intake hose. i need an adult.
09-28-2010, 05:25 PM
#45
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@warmonger88: If you don't have all the TB screws just right (including TPS), the simple computer on these engines will hunt all over for some stoichiometric peace - otherwise known as all values within range. Best $100 I have spent on my motor was letting a shop with all the proper instruments get all those screws correctly adjusted. The next best $100 was mixed in with about 16 other $100 friends when I had them put in new headgaskets and every other gasket in the motor! Long story--- don't ask.
11-23-2010, 10:47 AM
#46
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So my throttle sticking issue returned. I'm going to look into it again and see if the cold weather necessitates another adjustment of the throttle stop screw or if the screw changed positions.
The interesting thing is that the problem is always solved by stopping and starting the engine, or *almost* stalling it. Driving around, the idle will sometimes stay at around 2000 like shifting between gears but if I slow down in gear and push in the clutch when it's gotten near idle it will stay there or do a little surging from 1000 to 1400. If I kill the engine and start it again the idle is steady somewhere between 700 and 1000.
Does this still sound like a sticking throttle plate? Would the change in vacuum from killing the engine cause it to close all the way?
The interesting thing is that the problem is always solved by stopping and starting the engine, or *almost* stalling it. Driving around, the idle will sometimes stay at around 2000 like shifting between gears but if I slow down in gear and push in the clutch when it's gotten near idle it will stay there or do a little surging from 1000 to 1400. If I kill the engine and start it again the idle is steady somewhere between 700 and 1000.
Does this still sound like a sticking throttle plate? Would the change in vacuum from killing the engine cause it to close all the way?
11-23-2010, 06:47 PM
#47
Still not entirely sure, but shortly after this posting I had a minor misfire issue develop. After a number of months it turned out to be a blown headgasket which I will be fixing soon with an OEM-style gasket. The BHG may have been the issue all along, but if not it at least confounded the issue. I'll report back after I fix it if the idle issue is still there.
11-24-2010, 02:01 PM
#48
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Still not entirely sure, but shortly after this posting I had a minor misfire issue develop. After a number of months it turned out to be a blown headgasket which I will be fixing soon with an OEM-style gasket. The BHG may have been the issue all along, but if not it at least confounded the issue. I'll report back after I fix it if the idle issue is still there.
.
11-29-2010, 05:08 PM
#49
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@warmonger88: If you don't have all the TB screws just right (including TPS), the simple computer on these engines will hunt all over for some stoichiometric peace - otherwise known as all values within range. Best $100 I have spent on my motor was letting a shop with all the proper instruments get all those screws correctly adjusted. The next best $100 was mixed in with about 16 other $100 friends when I had them put in new headgaskets and every other gasket in the motor! Long story--- don't ask.
12-20-2010, 10:13 AM
#50
my truck seem to have every other idle problem in the book...
it's an 89 5-speed 4x4 with a 22re from a 1990 (~170K miles on engine)
I bought it last spring and it's always idled high when cold, around 2K RPM then like 800RPM or so once fully warm.
originally it had an aftermarket tach and I swapped to an SR5 cluster from a V6, attempted to adjust the new cluster tach to match the aftermarket one but if they matched at 2K then they'd be off at 3K and if they matched at 3K then they'd be off at 2K, so I set it the best i could, but it's probably off.
now that it's much colder out (I live in NH) it likes to idle at 2.5K when cold and has developed some other problems too.
1. sometimes, shortly after starting the truck with a warm engine, once it hits 2K RPM it will bouce between 1.5K and 2K.. it will continue doing this until I blip the throttle, then it will smooth out and climb to 2.5K where it stays until it's fully warm. I'm guessing this might be due to the "loop" scenario mentioned earlier due to the idle speed having been set too high (which it clearly is).
2. even after fully warm, when I lift off the throttle and put on the clutch and or put it in neutral the RPMS will want to rest at 2.5K RPM... a quick blip of the throttle and they'll slowly back down until it hits somewhere between 800 and 1.2K... based on what people have posted I'm guessing this might be due to a sticking dashpot
----------
I'm waiting to tackle the above because I've also got a CEL from a O2 sensor code. I believe this has existed since I've owned the truck but I didn't know until I swapped the clusters and discovered that the CEL bulb had been removed <_<
I discovered that the exhaust from the manifold back is completely "custom" and that the front O2 sensor was welded directly to the exhaust (probably why it was bad) I bought a brand new OEM mid pipe, new O2 sensors front and rear, a new cat and Pacesetter catback. I'll be taking care of that, along with installing new plugs and wires before I tackle the idle issues...
...however if anyone has any additional suggestions for things to look at for idle issues I'd love to hear them.
it's an 89 5-speed 4x4 with a 22re from a 1990 (~170K miles on engine)
I bought it last spring and it's always idled high when cold, around 2K RPM then like 800RPM or so once fully warm.
originally it had an aftermarket tach and I swapped to an SR5 cluster from a V6, attempted to adjust the new cluster tach to match the aftermarket one but if they matched at 2K then they'd be off at 3K and if they matched at 3K then they'd be off at 2K, so I set it the best i could, but it's probably off.
now that it's much colder out (I live in NH) it likes to idle at 2.5K when cold and has developed some other problems too.
1. sometimes, shortly after starting the truck with a warm engine, once it hits 2K RPM it will bouce between 1.5K and 2K.. it will continue doing this until I blip the throttle, then it will smooth out and climb to 2.5K where it stays until it's fully warm. I'm guessing this might be due to the "loop" scenario mentioned earlier due to the idle speed having been set too high (which it clearly is).
2. even after fully warm, when I lift off the throttle and put on the clutch and or put it in neutral the RPMS will want to rest at 2.5K RPM... a quick blip of the throttle and they'll slowly back down until it hits somewhere between 800 and 1.2K... based on what people have posted I'm guessing this might be due to a sticking dashpot
----------
I'm waiting to tackle the above because I've also got a CEL from a O2 sensor code. I believe this has existed since I've owned the truck but I didn't know until I swapped the clusters and discovered that the CEL bulb had been removed <_<
I discovered that the exhaust from the manifold back is completely "custom" and that the front O2 sensor was welded directly to the exhaust (probably why it was bad) I bought a brand new OEM mid pipe, new O2 sensors front and rear, a new cat and Pacesetter catback. I'll be taking care of that, along with installing new plugs and wires before I tackle the idle issues...
...however if anyone has any additional suggestions for things to look at for idle issues I'd love to hear them.
12-20-2010, 10:22 AM
#51
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I believe only the California trucks have two O2 sensors. Of course, it doesn't sound like you know where your truck has spent most of its life! Just be sure you've got some way to connect up two O2 sensors, otherwise send the aft one back.
[The aft sensor allows the ECM to monitor the performance of the Catalytic Converter. If the Cat fails, the aft sensor will switch in time with the front sensor, indicating that the Cat isn't doing anything.]
[The aft sensor allows the ECM to monitor the performance of the Catalytic Converter. If the Cat fails, the aft sensor will switch in time with the front sensor, indicating that the Cat isn't doing anything.]
12-20-2010, 10:35 AM
#52
I think it is actually a California model, I do know it has 2 O2 sensor plugs (the 2nd plug is empty) and IIRC it was actually 2 CEL codes, one for the front sensor and one for the rear, though honestly, the code descriptions were rather ambiguous.
considering it's not the original motor and the amount of things that have been hacked together on this truck... it's hard to determine what parts of the truck came from where.
considering it's not the original motor and the amount of things that have been hacked together on this truck... it's hard to determine what parts of the truck came from where.
Last edited by twistedsymphony; 12-20-2010 at 10:37 AM.
12-27-2010, 04:08 PM
#53
the weather has prevented me from really investigating this further but the other day I got home from work early and had some day light left, so I popped the hood while it was idling at 2.5K...
it turns out the spring on the throttle body is to blame for my idle issues, it doesn't return the butterfly to the full close position there is about 1-2 degrees of slack.
anyone know if I can buy a new replacement for just that spring, or how hard it would be to maybe wind it one rotation tighter?
it turns out the spring on the throttle body is to blame for my idle issues, it doesn't return the butterfly to the full close position there is about 1-2 degrees of slack.
anyone know if I can buy a new replacement for just that spring, or how hard it would be to maybe wind it one rotation tighter?
01-12-2011, 08:00 PM
#54
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okay i know that everyone is gonna tell me too look around and find out why but i cant find any idle issues concerning my problem, the truck when at idle sounds like my 350 in my chevy, just like it has a nasty cam, but when i drive the truck it runs completely smooth all the way through the rpm range. just when its idling it sounds like its missing and well sounds like a chevy v8 camming lol. could anyone tell me what could be causing this? oh and it idles at about 8 or 700 and likes to drop even lower when i am driving, i have tried to adjust the idle screw and it does absolutely nothing to the idle no matter how much i turn it.
01-14-2011, 06:08 AM
#56
I'm still having idle issues...
I've used the tuning guide to set the TPS and I've checked over the vacuum lines and nothing is leaking.
------
the truck wants to idle between 2K and 2.5K when cold
once warm it will try to climb to that RPM range, it will stay there until I blib the throttle at which point it will settle back down to around 1K
I thought there was an issue with the butterfly spring, I wound it one tighter so it doesn't "float" when closed anymore but it didn't make a difference... I thought it might have been related to the dashpot but I removed it completely and the problem still persists.
So TPS set properly
Vac line checks out
dashpot ruled out
what could be causing this?
I've used the tuning guide to set the TPS and I've checked over the vacuum lines and nothing is leaking.
------
the truck wants to idle between 2K and 2.5K when cold
once warm it will try to climb to that RPM range, it will stay there until I blib the throttle at which point it will settle back down to around 1K
I thought there was an issue with the butterfly spring, I wound it one tighter so it doesn't "float" when closed anymore but it didn't make a difference... I thought it might have been related to the dashpot but I removed it completely and the problem still persists.
So TPS set properly
Vac line checks out
dashpot ruled out
what could be causing this?
Last edited by twistedsymphony; 01-14-2011 at 06:09 AM.
01-14-2011, 06:29 AM
#57
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okay i know that everyone is gonna tell me too look around and find out why but i cant find any idle issues concerning my problem, the truck when at idle sounds like my 350 in my chevy, just like it has a nasty cam, but when i drive the truck it runs completely smooth all the way through the rpm range. just when its idling it sounds like its missing and well sounds like a chevy v8 camming lol. could anyone tell me what could be causing this? oh and it idles at about 8 or 700 and likes to drop even lower when i am driving, i have tried to adjust the idle screw and it does absolutely nothing to the idle no matter how much i turn it.
01-19-2011, 12:13 PM
#58
found this in another thread:
what he describes is IDENTICAL to the problems I'm having (not to mention I've tried the same solutions he did without any success)... I haven't tried his cable cleaning method yet but I'm going to give it a go... maybe just order a new throttle cable from Toyota.
Oops! Fooled by randomness. My idle problem was not solved after all; just a temporary reprieve at the time I wrote the original reply. Subsequently I did finally discover and correct the problem.
To recount the problem-
1. Intermittently high, but steady idle (1500-2000 rpms) for over 2 years which resolved by popping the gas pedal.
2. Initially only in summertime, but had progressed to year round.
3. Discovered if the gas was released slowly problem occurred, but if released suddenly, no problem.
4. The throttle assembly could easily (i.e., light digital pressure) be returned to normal when high idle was present.
5. Dashpot ruled out by inspection and using flat bladed screwdriver to push rod going to dashpot diaphragm down during high idle with no effect on rpms.
6. Thorough cleaning of throttle body with throttle/choke cleaner--no effect (but lots of gunk).
Decided it had to be either:
1) weak throttle valve spring--but why not problem all the time?
2) dirty throttle valve rod--why didn't cleaning affect?
3) throttle cable hanging up--made sense with 320,000 miles, sheath may contain gunk increasing friction between cable and sheath, which could be exaggerated in summer by heat expanding metal cable. Fast release of throttle would overcome gunk friction; hence, normal operation when gas pedal popped.
Removed 2 bolts holding throttle cable sheath flange to firewall, and the cable from the throttle assembly. Attached cable lubrication tool to cable end. Sprayed in lubricant until draining at firewall. To my surprise it also drained from undiscovered crack in cable sheath at sharp bend before the flange. Reassembled, took for long drive with many stops--works fine now. I suspect a crack in the sheath allowed water in and the cable has begun to rust at that site. My current plan is to seal sheath with heat shrink and see if I can get another 20 years out of it.
To recount the problem-
1. Intermittently high, but steady idle (1500-2000 rpms) for over 2 years which resolved by popping the gas pedal.
2. Initially only in summertime, but had progressed to year round.
3. Discovered if the gas was released slowly problem occurred, but if released suddenly, no problem.
4. The throttle assembly could easily (i.e., light digital pressure) be returned to normal when high idle was present.
5. Dashpot ruled out by inspection and using flat bladed screwdriver to push rod going to dashpot diaphragm down during high idle with no effect on rpms.
6. Thorough cleaning of throttle body with throttle/choke cleaner--no effect (but lots of gunk).
Decided it had to be either:
1) weak throttle valve spring--but why not problem all the time?
2) dirty throttle valve rod--why didn't cleaning affect?
3) throttle cable hanging up--made sense with 320,000 miles, sheath may contain gunk increasing friction between cable and sheath, which could be exaggerated in summer by heat expanding metal cable. Fast release of throttle would overcome gunk friction; hence, normal operation when gas pedal popped.
Removed 2 bolts holding throttle cable sheath flange to firewall, and the cable from the throttle assembly. Attached cable lubrication tool to cable end. Sprayed in lubricant until draining at firewall. To my surprise it also drained from undiscovered crack in cable sheath at sharp bend before the flange. Reassembled, took for long drive with many stops--works fine now. I suspect a crack in the sheath allowed water in and the cable has begun to rust at that site. My current plan is to seal sheath with heat shrink and see if I can get another 20 years out of it.
04-25-2011, 07:19 PM
#59
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found this in another thread:
what he describes is IDENTICAL to the problems I'm having (not to mention I've tried the same solutions he did without any success)... I haven't tried his cable cleaning method yet but I'm going to give it a go... maybe just order a new throttle cable from Toyota.
what he describes is IDENTICAL to the problems I'm having (not to mention I've tried the same solutions he did without any success)... I haven't tried his cable cleaning method yet but I'm going to give it a go... maybe just order a new throttle cable from Toyota.
Did you ever figure out your problem twistedsymphony? Mine is doing the same thing. Since I got the truck 2months ago it idles between 2000- 2500 rpm during warm up then it will kick down and sit around 1000 rpm once it reaches oper. temp. I just did an oil change and had to pry off an over-torqued oil filter with screw drivers! And now my idle will still be around 2k- 2500 rpm during warm up but then once it reaches operating temp and in neutral it wants to sit at 1500 rpm and when i press on my brakes it drops to 900 and surges between 900 and 1200 rpm while holding brakes?? Im gonna check all the vacuum hoses (i may have bumped changing stubborn filter) and try to set the idle screw after work 2morrow and maybe change the TPS. Hopefully i fix it. I will post and let everyone know what i figure out. Any help would be greatly appreciated in case i cant figure it out! Even though im sure the answer is here on the site somewhere! THanks!
05-01-2011, 10:40 AM
#60
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Did you ever figure out your problem twistedsymphony? Mine is doing the same thing. Since I got the truck 2months ago it idles between 2000- 2500 rpm during warm up then it will kick down and sit around 1000 rpm once it reaches oper. temp. I just did an oil change and had to pry off an over-torqued oil filter with screw drivers! And now my idle will still be around 2k- 2500 rpm during warm up but then once it reaches operating temp and in neutral it wants to sit at 1500 rpm and when i press on my brakes it drops to 900 and surges between 900 and 1200 rpm while holding brakes?? Im gonna check all the vacuum hoses (i may have bumped changing stubborn filter) and try to set the idle screw after work 2morrow and maybe change the TPS. Hopefully i fix it. I will post and let everyone know what i figure out. Any help would be greatly appreciated in case i cant figure it out! Even though im sure the answer is here on the site somewhere! THanks!
Well first of all i forgot to mention i have a 22re 5spd 4x4 91 pickup with unknown mileage. Ive been having idle probs like i mentioned above since i bought the truck. Then after doing an oil change i had problems with it surging which would worsen when i press the brakes. I drove it like that for a week and it gradually got worse. Began surging all the time no matter the engine temp or if i was pressing the brakes or not. I tried turning in the idle screw all week and it had no effect on the engine. Until yesterday, I turned the idle screw in almost all the way and got the idle to drop to around 900 rpms. It was idling smoothly and no more surging. But ive read on here that if the idle screw is that far in im compensating for a vacuum leak. So i was still concerned but it was running alot better with more power and throttle response and smoother shifts.....I was still concerned though. So i went and replaced my PCV valve and my air filter( which needed it badly). Now remember i set my idle to around 850-900rpms, but on my next drive it started dropping to 500rpms and wanting to stay there when the engine warmed up. So now im gonna have to turn my idle back up to factory specs.
Bottom line i think my vacuum leak may have been caused by a plugged PCV valve. Since after i changed that and the air filter the idle dropped even more. Either way im happy and just wanted to inform everyone hear about my problems and how i fixed them! Hope this info can help someone! I love my toyota!!! And thanks to this site i will be able to keep it running!!
