Versatile 1st Gear October 8, 2011 Share October 8, 2011 Hi Bros, I encountered car tremble issue whenever i starts to brake followed by completed stop. I just did a battery changed because the battery when dead on me. I noticed the voltage dropped from 14v to 12/11v whenever i brake followed by completed stop. After tremble for few secs, the voltage went up to 14v again. No issues of trembling when moving and the voltage is stable at 14v.. Anyone encountered this before? Could it due to battery not full charged yet or alternator faulty? Please advice. ↡ Advertisement Link to post Share on other sites More sharing options...
Amuroboy 1st Gear October 8, 2011 Share October 8, 2011 Stop also tremble right? Around engine area? Link to post Share on other sites More sharing options...
Chickensoup 1st Gear October 8, 2011 Share October 8, 2011 Brake Servo vacuum leak. The low voltage is because of engine almost stall, So alternator output voltage no enough due to low rpm. 12v + is battery voltage and then when engine comes back to normal idle speed, the voltage goes back to 14v due to high enough rpm for charging output. Link to post Share on other sites More sharing options...
Versatile 1st Gear October 8, 2011 Author Share October 8, 2011 Stop also tremble right? Around engine area? The tremble only occurs when my car is coming to a stop and tremble for a few sec then voltage will resume to standard 14v. I'm not sure whether is it engine area.. the whole tremble can be felt everywhere! Link to post Share on other sites More sharing options...
Versatile 1st Gear October 8, 2011 Author Share October 8, 2011 (edited) Brake Servo vacuum leak. The low voltage is because of engine almost stall, So alternator output voltage no enough due to low rpm. 12v + is battery voltage and then when engine comes back to normal idle speed, the voltage goes back to 14v due to high enough rpm for charging output. Hi Bro, What's a brake servo vacuum leak? My friend said could be my rectifier issue that causes the tremble meaning even after battery changed, the charging is not constant. However, this is only assumption as i can only find out next week when i send my car down for servicing and also for a check. If it's the brake servo vacuum leak, how much will it cost to replace? And yes, engine almost stall and it stall quite a numbers of time especially when i do a reverse. I have to keep rev-ing to keep my engine alive. Is it dangerous for daily driving if i never resolve the leak asap? Funny part was before the battery, everything was normal.. trembling only start after the battery replace. Edited October 8, 2011 by Versatile Link to post Share on other sites More sharing options...
Wolfy3769 2nd Gear October 9, 2011 Share October 9, 2011 could be ur ECU kena reset when u change the battery. just do a ECU reset again... follow ur manual, ur car should be fine. after ECU reset, the ideal throttle setting might be a bit off.. thus u notice the RPM drop to 800 or lower.. that time, the engine will tremble...cause is in a stage of dying, apply abit gas, to bring up the RPM slightly higher.. dont over do it else ur idealing speed will be too high, ur mileage will suffer. Link to post Share on other sites More sharing options...
Versatile 1st Gear October 9, 2011 Author Share October 9, 2011 could be ur ECU kena reset when u change the battery. just do a ECU reset again... follow ur manual, ur car should be fine. after ECU reset, the ideal throttle setting might be a bit off.. thus u notice the RPM drop to 800 or lower.. that time, the engine will tremble...cause is in a stage of dying, apply abit gas, to bring up the RPM slightly higher.. dont over do it else ur idealing speed will be too high, ur mileage will suffer. Oh s--t, i dont have manual. Tried to find on how to reset ECU but quite invaild. Link to post Share on other sites More sharing options...
Gendut 2nd Gear October 9, 2011 Share October 9, 2011 Brake Servo vacuum leak. The low voltage is because of engine almost stall, So alternator output voltage no enough due to low rpm. 12v + is battery voltage and then when engine comes back to normal idle speed, the voltage goes back to 14v due to high enough rpm for charging output. Link to post Share on other sites More sharing options...
Friendstar Supercharged October 9, 2011 Share October 9, 2011 Brake Servo vacuum leak. The low voltage is because of engine almost stall, So alternator output voltage no enough due to low rpm. 12v + is battery voltage and then when engine comes back to normal idle speed, the voltage goes back to 14v due to high enough rpm for charging output. hey watever u'r saying makes some sense, but can rephrase again? Link to post Share on other sites More sharing options...
Chickensoup 1st Gear October 9, 2011 Share October 9, 2011 The brake servo assistance (brake servo is the huge black thing attached to the brake fluid reservior) runs on vacuum from engine tapping the vacuum from inlet manifold. There is a one way valve to control vacuum going into barke servo. If this one way valve or the servo itself is faulty, then whenever the braking starts, the vacuum keeps flowing to the brake servo. Then the inlet manifold lost too much vacuum and the engine has not enough suction to suck air/petrol, so stalling can occur. If you off aircon, this condition will improve because less load from compressor. But this is not the way to solve it. When engine is about to stall, the rpm will be low so the alternator cannot generate charge hence voltage drops. Next thing could be what another forumer said, change of battery cause the ECU memory to be reset due to disconnected battery. The throttle position sensor needs to be reset. This is unlikely in Japanese design. Some European high performance vehicle have this problem when battery is disconnected. Link to post Share on other sites More sharing options...
Chickensoup 1st Gear October 9, 2011 Share October 9, 2011 Oh s--t, i dont have manual. Tried to find on how to reset ECU but quite invaild. Try this.....Park car with engine idling, free gear, step on the brake...did the rpm drop? If yes, confirm vacuum leak along brake servo pipe. If no, then could be TPS (Throttle Position Sensor). To reset, off engine, disconnect battery for say one hour (this is to clear out residual charge in ECU held by capacitors), then reconnect. Your car manual or auto? If auto is it CVT, normal auto or DSG? Link to post Share on other sites More sharing options...
Friendstar Supercharged October 9, 2011 Share October 9, 2011 U r a crazy guru. Nice explanation there! Link to post Share on other sites More sharing options...
Hulk 1st Gear October 9, 2011 Share October 9, 2011 (edited) Hi Bros, I encountered car tremble issue whenever i starts to brake followed by completed stop. I just did a battery changed because the battery when dead on me. I noticed the voltage dropped from 14v to 12/11v whenever i brake followed by completed stop. After tremble for few secs, the voltage went up to 14v again. No issues of trembling when moving and the voltage is stable at 14v.. Anyone encountered this before? Could it due to battery not full charged yet or alternator faulty? Please advice. Bro u start to brake and trembling, can u feel on handwheel? If yes, That is your rotor warped liao. Nothing got to do with battery or even voltage, don't make sense. Go skim your front 2 rotors. Edited October 9, 2011 by Hulk Link to post Share on other sites More sharing options...
Picanto 3rd Gear October 9, 2011 Share October 9, 2011 Try this.....Park car with engine idling, free gear, step on the brake...did the rpm drop? If yes, confirm vacuum leak along brake servo pipe. If no, then could be TPS (Throttle Position Sensor). To reset, off engine, disconnect battery for say one hour (this is to clear out residual charge in ECU held by capacitors), then reconnect. Your car manual or auto? If auto is it CVT, normal auto or DSG? NONSENSE. dun be a a smart aleck Link to post Share on other sites More sharing options...
Versatile 1st Gear October 9, 2011 Author Share October 9, 2011 Try this.....Park car with engine idling, free gear, step on the brake...did the rpm drop? If yes, confirm vacuum leak along brake servo pipe. If no, then could be TPS (Throttle Position Sensor). To reset, off engine, disconnect battery for say one hour (this is to clear out residual charge in ECU held by capacitors), then reconnect. Your car manual or auto? If auto is it CVT, normal auto or DSG? Hi Bro, Mines MT transmission. The car doesn't have that issue before battery change. So I don't believe it's brake servo leak. I called up my mech and was told that ECU could be reset and causes it. I tried performing steps to reset my ECU according to swift UK site by flooring on pedal for 30sec, turn ignition on, step on 30sec again but problem still persist. Guess I will leave it at it is as it's pretty dangerous to drive now because the stall will caused the steering to lock. Boh pian, tomorrow send to workshop or diagnostic Liao. Link to post Share on other sites More sharing options...
Versatile 1st Gear October 9, 2011 Author Share October 9, 2011 Bro u start to brake and trembling, can u feel on handwheel? If yes, That is your rotor warped liao. Nothing got to do with battery or even voltage, don't make sense. Go skim your front 2 rotors. Hi Bro, Handwheel = steering? No, no vibration/trembling. It's the whole car that vibrate. Voltage dropped from 14v to 12v and engine starts to go into stalling feel mode. Link to post Share on other sites More sharing options...
Versatile 1st Gear October 9, 2011 Author Share October 9, 2011 Try this.....Park car with engine idling, free gear, step on the brake...did the rpm drop? If yes, confirm vacuum leak along brake servo pipe. If no, then could be TPS (Throttle Position Sensor). To reset, off engine, disconnect battery for say one hour (this is to clear out residual charge in ECU held by capacitors), then reconnect. Your car manual or auto? If auto is it CVT, normal auto or DSG? Hi Bro, What's the standard TPS reading during idle? I have a scangauge installed. So I can monitor on my end. Link to post Share on other sites More sharing options...
Chickensoup 1st Gear October 9, 2011 Share October 9, 2011 Hi Bro, What's the standard TPS reading during idle? I have a scangauge installed. So I can monitor on my end. Sorry I don't know the specs for your car. ↡ Advertisement Link to post Share on other sites More sharing options...
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