Introduction
First let me introduce myself as this is my first post
, I'm Mike from the Netherlands and recently bought a secondhand 2009 Suzuki Swift 1.3. I have this car for a little over 4 months now.
Problem
A month and a half ago I started to experience some serious RPM drops while stopping for a traffic light or such. According to my tachometer / OBD2 scanner the RPMs dropped as low as 400RPM. While I visually saw it happen on my tachometer, I also could feel the engine vibrate like it's about to stall. Since the day the problem started I tried numerous things to fix the issue. At the moment I'm quite sure something in my electrical system is causing this RPM drop. When I let my car idle (whilst it is fully warmed up) and have no electrical components turned on the engine revs are at a nice ~750RPM. Then when I'm starting to put some electrical load on the system the revs on the tachometer visually drops a 100-200RPM and the engine starts running rough, after a couple seconds the RPMs rise again, however the engine is still running rough like it's strained by the alternator. Also the headlights are somewhat dimmed oppose to when everything but the headlights are turned off. If I rev up the RPMs and then release the accelerator, while all electrical accessoires are turned on, the RPM drops sharply to a 400-500 RPM and then stabilize at a nice 750RPM again. The same thing is happening when I'm stopping for a traffic light. When I'm revving or stopping for a traffic light without any electrical load everything is good and the idle does not undershoot to a 400-500RPM.
Side problem
Sometimes, like once in two to three weeks, the engine won't fire up the first time. It cranks OK, but just won't turn on? The second (sometimes the third) time the engine starts but with a lot of hesitation. Just like the engine was flooded or something. It doesn't seem to be flooded though as no smoke from the exhaust appears when it starts. It also does not depend on the temperature of the engine, it has both done it when the engine was warm and shutoff for only 20 minutes while I was shopping. The other time it did it after it stayed off during the weekend.
Things I've tried
The past two months or so I have tried numerous things:
Things I consider doing
Even though the alternator seems to work fine, I'm still considering replacing the thing. Could it be that the alternator is outputting enough current but somehow loads the engine too much while powering everything?
Any other suggestion are welcome, thanks for all your help.
First let me introduce myself as this is my first post
, I'm Mike from the Netherlands and recently bought a secondhand 2009 Suzuki Swift 1.3. I have this car for a little over 4 months now.Problem
A month and a half ago I started to experience some serious RPM drops while stopping for a traffic light or such. According to my tachometer / OBD2 scanner the RPMs dropped as low as 400RPM. While I visually saw it happen on my tachometer, I also could feel the engine vibrate like it's about to stall. Since the day the problem started I tried numerous things to fix the issue. At the moment I'm quite sure something in my electrical system is causing this RPM drop. When I let my car idle (whilst it is fully warmed up) and have no electrical components turned on the engine revs are at a nice ~750RPM. Then when I'm starting to put some electrical load on the system the revs on the tachometer visually drops a 100-200RPM and the engine starts running rough, after a couple seconds the RPMs rise again, however the engine is still running rough like it's strained by the alternator. Also the headlights are somewhat dimmed oppose to when everything but the headlights are turned off. If I rev up the RPMs and then release the accelerator, while all electrical accessoires are turned on, the RPM drops sharply to a 400-500 RPM and then stabilize at a nice 750RPM again. The same thing is happening when I'm stopping for a traffic light. When I'm revving or stopping for a traffic light without any electrical load everything is good and the idle does not undershoot to a 400-500RPM.
Side problem
Sometimes, like once in two to three weeks, the engine won't fire up the first time. It cranks OK, but just won't turn on? The second (sometimes the third) time the engine starts but with a lot of hesitation. Just like the engine was flooded or something. It doesn't seem to be flooded though as no smoke from the exhaust appears when it starts. It also does not depend on the temperature of the engine, it has both done it when the engine was warm and shutoff for only 20 minutes while I was shopping. The other time it did it after it stayed off during the weekend.
Things I've tried
The past two months or so I have tried numerous things:
- Replaced the battery
- Replaced all filters (except fuel filter)
- Replaced engine and gearbox oil
- Replaced spark plugs
- Replaced PCV valve
- Cleaned throttle body (whilst in the car)
- Cleaned EGR valve (removed assembly from engine)
- Visual inspection of vacuum leaks
- Unplugged brake booster, no success
- Unplugged MAF sensor, no succes
- Checked for error codes in ECU, no error codes were read
- Relearned the ECU its idle map
- Checked and measured various power/ground connections under load, resistance seems to be OK.
- Measured battery terminal voltage under load, alternator seems to charge it at a nice ~13.7V.
Things I consider doing
Even though the alternator seems to work fine, I'm still considering replacing the thing. Could it be that the alternator is outputting enough current but somehow loads the engine too much while powering everything?
Any other suggestion are welcome, thanks for all your help
.
