4 runner pulsing when brakes applied
11-13-2010, 02:42 PM
#22
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11-13-2010, 02:45 PM
#23
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But then why is the idle high in the first place?
Make sure coolant is full! Low coolant will cause higher idle, which will cause the surging engine while braking.
Make sure coolant is full! Low coolant will cause higher idle, which will cause the surging engine while braking.
11-13-2010, 02:58 PM
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Ok thanks for the pics. The coolent is good. The guy said the rad has a small leak so dads been keeping an eye on the coolent. It did sit for awhile we had to free the breaks up and stuff. He said when he parked it it was fine, then when he went to start it one day and took it for a drive it started pulsing. I think it only does it once its warmed up too. Not when you first start it.
11-13-2010, 03:22 PM
#28
For the record...
1. I'm not a kid any more being 35 years old.
2. I have no intentions on recieving ASE certification. That particular ranking means squat to me. I have yet to meet an ASE certified technician or mechanic in real life that could actually teach me anything. My brother is actually an ASE certified mechanic and has been of NO help to me with regards to giving me good advice, explaining technical matters, or showing me how to do ANYTHING mechanical. As a matter of fact it's been quite the opposite, if I really did listen to him or allow him to help me work on cars/trucks I'd be in pretty sad shape. He's ALWAYS wrong and couldn't fix a broken tail light on his own. I've watched him make stupid mistake after stupid mistake, chasing his tail for days/weeks/months on end trying to solve the most uncomplicated of problems. So they must hand out those certificates to some pretty unqualified people.
3. Auto mechanics, automotive engineering, and electronic hardware design concepts are far to basic to be at all hard for me to understand or grasp. If I've said it once I've said it a thousand times, none of this stuff "is rocket science". Speaking of which, if it doesn't involve something on the level of rocket science or say quantum mechanics, then I'll definitely understand the physics that underly it's theories of operation. And being that quantum mechanics isn't really "knowable" at all, meaning NOBODY(including it's most eminent theorists)truly get's it, that says much.
4. I'm actually self-taught when it comes to all these things. Any information I've found in regards to these subjects has been found in the public domain. I never have, and never will, pay someone else to "school" me on any matters. Let alone something as basic and uncomplicated as figuring out how cars work. Colleges, trade schools, and other such training courses are for the weak and feable minded, whom need spoon fed knowledge like little babies.
5. It's actually the case that I have less experience in performing all the tasks which I have a full knowledge of. Though I have aquired a great deal of hands-on experience working on cars/trucks in my lifetime. But I know far more than I've done. Just because I haven't done something doesn't mean I have no understanding of how or why it's done. It's generally the case that I have a quite complete knowledge of it BEFORE I attempt to apply that knowledge to a given scenario.
6. If any of you think that I give a rat's ass what you think of my mechanical know how, you're sadly mistaken. Name one thing that you've really taught me on the subject. As I've also stated prior, I'm not the question asker, I'm the question answerer. And I don't open my mouth to speak on subjects which I don't fully understand and haven't, to some extent atleast, mastered. I'm not trying to impress anybody. I'm trying help those who ask for assistance. If that offends you, TOO BAD! When I need your help, or would like your opinion on something I'll ask. Don't hold your breath...it could be awhile...a VERY LONG WHILE! 'Till then, bash away you pathetic losers!
On the issue this thread I only have a small bit of information that I neglected to mention. It is however crucial. So, though I long not to participate in this unending and worthless debate, it's only fair that I include it as supplement to what I've already laid out. Not that it's going to make much sense to any of you. It's none-the-less important.
So here goes:
The VSS outputs no SPD signal when the reading is 0. Hence that signal is not input to the ECM when the vehicle is at a stop. How is that signal used by the ECM to adjust the fuel cut rpm threshold at idle rpm while the vehicle is stopped? It isn't.
Next up, the stop light switch/STP signal. How is it used by the ECM to adjust the fuel cut rpm threshold? When the vehicle is stopped and the SPD signal is absent, in most cases isn't. Why would it be? It is however an important factor in determining how fast the vehicle is decelerating though. So that's when the ECM compares it to the SPD signal to determine whether the vehicle is "coasting" or "braking" to a stop. And adjusts the fuel cut rpm threshold accordingly. It serves no purpose AT ALL when the vehicle is stopped, aside from in 2WD A/T applications(supposedly).
CASE CLOSED
1. I'm not a kid any more being 35 years old.
2. I have no intentions on recieving ASE certification. That particular ranking means squat to me. I have yet to meet an ASE certified technician or mechanic in real life that could actually teach me anything. My brother is actually an ASE certified mechanic and has been of NO help to me with regards to giving me good advice, explaining technical matters, or showing me how to do ANYTHING mechanical. As a matter of fact it's been quite the opposite, if I really did listen to him or allow him to help me work on cars/trucks I'd be in pretty sad shape. He's ALWAYS wrong and couldn't fix a broken tail light on his own. I've watched him make stupid mistake after stupid mistake, chasing his tail for days/weeks/months on end trying to solve the most uncomplicated of problems. So they must hand out those certificates to some pretty unqualified people.
3. Auto mechanics, automotive engineering, and electronic hardware design concepts are far to basic to be at all hard for me to understand or grasp. If I've said it once I've said it a thousand times, none of this stuff "is rocket science". Speaking of which, if it doesn't involve something on the level of rocket science or say quantum mechanics, then I'll definitely understand the physics that underly it's theories of operation. And being that quantum mechanics isn't really "knowable" at all, meaning NOBODY(including it's most eminent theorists)truly get's it, that says much.
4. I'm actually self-taught when it comes to all these things. Any information I've found in regards to these subjects has been found in the public domain. I never have, and never will, pay someone else to "school" me on any matters. Let alone something as basic and uncomplicated as figuring out how cars work. Colleges, trade schools, and other such training courses are for the weak and feable minded, whom need spoon fed knowledge like little babies.
5. It's actually the case that I have less experience in performing all the tasks which I have a full knowledge of. Though I have aquired a great deal of hands-on experience working on cars/trucks in my lifetime. But I know far more than I've done. Just because I haven't done something doesn't mean I have no understanding of how or why it's done. It's generally the case that I have a quite complete knowledge of it BEFORE I attempt to apply that knowledge to a given scenario.
6. If any of you think that I give a rat's ass what you think of my mechanical know how, you're sadly mistaken. Name one thing that you've really taught me on the subject. As I've also stated prior, I'm not the question asker, I'm the question answerer. And I don't open my mouth to speak on subjects which I don't fully understand and haven't, to some extent atleast, mastered. I'm not trying to impress anybody. I'm trying help those who ask for assistance. If that offends you, TOO BAD! When I need your help, or would like your opinion on something I'll ask. Don't hold your breath...it could be awhile...a VERY LONG WHILE! 'Till then, bash away you pathetic losers!
On the issue this thread I only have a small bit of information that I neglected to mention. It is however crucial. So, though I long not to participate in this unending and worthless debate, it's only fair that I include it as supplement to what I've already laid out. Not that it's going to make much sense to any of you. It's none-the-less important.
So here goes:
The VSS outputs no SPD signal when the reading is 0. Hence that signal is not input to the ECM when the vehicle is at a stop. How is that signal used by the ECM to adjust the fuel cut rpm threshold at idle rpm while the vehicle is stopped? It isn't.
Next up, the stop light switch/STP signal. How is it used by the ECM to adjust the fuel cut rpm threshold? When the vehicle is stopped and the SPD signal is absent, in most cases isn't. Why would it be? It is however an important factor in determining how fast the vehicle is decelerating though. So that's when the ECM compares it to the SPD signal to determine whether the vehicle is "coasting" or "braking" to a stop. And adjusts the fuel cut rpm threshold accordingly. It serves no purpose AT ALL when the vehicle is stopped, aside from in 2WD A/T applications(supposedly).
CASE CLOSED
Last edited by MudHippy; 11-13-2010 at 04:01 PM.
11-13-2010, 03:26 PM
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ROFL!!! STOP!! Tomorrow he will log on and say "turned the idle down and the surging ceased" WOW!! thanks for the help guys. Stop making it worse, it will fix it!!
(edit) case closed.. awesome
No hard feelings man, but you can't make this stuff up. We've learned these kind of things from experience
(edit) case closed.. awesome
No hard feelings man, but you can't make this stuff up. We've learned these kind of things from experience
Last edited by lftd_86_yota; 11-13-2010 at 03:30 PM.
11-13-2010, 03:33 PM
#33
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11-13-2010, 03:36 PM
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The idle IS set too high. If it wasn't dark out I would go out to the driveway with my phone camcorder, turn the idle up, depress the brake pedal and duplicate the exact problem being described. With only the change in my pocket. And then post it of course.
Last edited by lftd_86_yota; 11-13-2010 at 03:46 PM.
11-13-2010, 03:43 PM
#35
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I drove it home for him but i cant remember exactly where the rpms were. I'm not forsure but it might have been dropping to 1000 and raising to 1300 but like i say i cant really remember. I'll find out tomorrow.
11-13-2010, 03:58 PM
#36
Having to turn down the idle? Why? Why was it too high to begin with? Let me guess, somebody got in there and turned it up when you weren't looking right?
As I've said, if the idle is too high you've got a vacuum leak somewhere that caused it. Problem solved addressing it by turning the idle down? NONE!
It might work to temporarily solve some peculiar symptom. DOESN'T FIX THE VACUUM LEAK THOUGH DOES IT!
As I've said, if the idle is too high you've got a vacuum leak somewhere that caused it. Problem solved addressing it by turning the idle down? NONE!
It might work to temporarily solve some peculiar symptom. DOESN'T FIX THE VACUUM LEAK THOUGH DOES IT!
11-13-2010, 04:16 PM
#37
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Having to turn down the idle? Why? Why was it too high to begin with? Let me guess, somebody got in there and turned it up when you weren't looking right?
As I've said, if the idle is too high you've got a vacuum leak somewhere that caused it. Problem solved addressing it by turning the idle down? NONE!
It might work to temporarily solve some peculiar symptom. DOESN'T FIX THE VACUUM LEAK THOUGH DOES IT!
As I've said, if the idle is too high you've got a vacuum leak somewhere that caused it. Problem solved addressing it by turning the idle down? NONE!
It might work to temporarily solve some peculiar symptom. DOESN'T FIX THE VACUUM LEAK THOUGH DOES IT!
Now having said that I do understand that your vacuum leak argument does have merit although in this instance I firmly believe it's the idle that is out, not a vacuum issue and not caused by a vacuum issue.
I guess we'll just have to wait and see. If you're right then I'll give you the due credit.
11-13-2010, 04:21 PM
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I actually just fixed this problem on my truck. Malfunctioning idle air control valve was causing the idle to be too high. Idle control screw on throttle body would bottom out before the idle to would go low enough so after a painstaking amount of troubleshooting and research I narrowed it down to the culprit. Problem solved. Idle was too high.
11-13-2010, 04:30 PM
#39
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I actually just fixed this problem on my truck. Malfunctioning idle air control valve was causing the idle to be too high. Idle control screw on throttle body would bottom out before the idle to would go low enough so after a painstaking amount of troubleshooting and research I narrowed it down to the culprit. Problem solved. Idle was too high.
Did you replace the IACV or fix it somehow? Now that the weather has turned colder mine is idling high until it warms up and it drives me nuts.
Thanks.
/thread hijack over
11-13-2010, 04:42 PM
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