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Inconsistent RPM


Goldenvodka
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Hi guys seeking help here for some issues for my ride.

Assuming the car has been warmed up after a 45min drive.

- approaching traffic light RPM seems to decrease to about 400-500. Engine vibrates but not violently.however it did not stall once. Once coming to a stand still RPM will hover around 600 rpm. Slight vibration felt but car did not stall. All these is when the vehicle is in D mode.

- idle in P or N mode have a very slight vibration that seems normal. Around 700-800rpm. Vibration is definitely much lesser than in D mode.


- When engaged in R mode. The vehicle will jerk and rpm drops to 600. It reverses normally. No need to step on the gas however vibration can be clearly felt

Servicing has been done recently
New oil for both engine and transmission
New coolant
New spark plug
New MAF sensor
Last but not least. Welcome for any valuable feedback. Thanks!

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Hi guys seeking help here for some issues for my ride.

 

Assuming the car has been warmed up after a 45min drive.

 

- approaching traffic light RPM seems to decrease to about 400-500. Engine vibrates but not violently.however it did not stall once. Once coming to a stand still RPM will hover around 600 rpm. Slight vibration felt but car did not stall. All these is when the vehicle is in D mode.

 

- idle in P or N mode have a very slight vibration that seems normal. Around 700-800rpm. Vibration is definitely much lesser than in D mode.

 

 

- When engaged in R mode. The vehicle will jerk and rpm drops to 600. It reverses normally. No need to step on the gas however vibration can be clearly felt

 

Servicing has been done recently

New oil for both engine and transmission

New coolant

New spark plug  Check

New MAF sensor  Check

Last but not least. Welcome for any valuable feedback. Thanks!

 

What else left to check?

How about vacuum leak? Check vacuum hoses.

Faulty ignition coil?

 

Good luck.

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Hi guys seeking help here for some issues for my ride.

 

Assuming the car has been warmed up after a 45min drive.

 

- approaching traffic light RPM seems to decrease to about 400-500. Engine vibrates but not violently.however it did not stall once. Once coming to a stand still RPM will hover around 600 rpm. Slight vibration felt but car did not stall. All these is when the vehicle is in D mode.

 

- idle in P or N mode have a very slight vibration that seems normal. Around 700-800rpm. Vibration is definitely much lesser than in D mode.

 

 

- When engaged in R mode. The vehicle will jerk and rpm drops to 600. It reverses normally. No need to step on the gas however vibration can be clearly felt

 

Servicing has been done recently

New oil for both engine and transmission

New coolant

New spark plug

New MAF sensor

Last but not least. Welcome for any valuable feedback. Thanks!

I have similar problem like yours.

Done throttle cleaning but still problem exist.

Finally fault is spark plug housing crack.

Your spark plug might be new but when the mechanic over tightened might cause crack.

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Hi guys seeking help here for some issues for my ride.

 

Assuming the car has been warmed up after a 45min drive.

 

- approaching traffic light RPM seems to decrease to about 400-500. Engine vibrates but not violently.however it did not stall once. Once coming to a stand still RPM will hover around 600 rpm. Slight vibration felt but car did not stall. All these is when the vehicle is in D mode.

 

- idle in P or N mode have a very slight vibration that seems normal. Around 700-800rpm. Vibration is definitely much lesser than in D mode.

 

 

- When engaged in R mode. The vehicle will jerk and rpm drops to 600. It reverses normally. No need to step on the gas however vibration can be clearly felt

 

Servicing has been done recently

New oil for both engine and transmission

New coolant

New spark plug

New MAF sensor

Last but not least. Welcome for any valuable feedback. Thanks!

which car, model and engine, so anyone with similar experience can share.
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Hi guys seeking help here for some issues for my ride.

 

Assuming the car has been warmed up after a 45min drive.

 

- approaching traffic light RPM seems to decrease to about 400-500. Engine vibrates but not violently.however it did not stall once. Once coming to a stand still RPM will hover around 600 rpm. Slight vibration felt but car did not stall. All these is when the vehicle is in D mode.

 

- idle in P or N mode have a very slight vibration that seems normal. Around 700-800rpm. Vibration is definitely much lesser than in D mode.

 

 

- When engaged in R mode. The vehicle will jerk and rpm drops to 600. It reverses normally. No need to step on the gas however vibration can be clearly felt

 

Servicing has been done recently

New oil for both engine and transmission

New coolant

New spark plug

New MAF sensor

Last but not least. Welcome for any valuable feedback. Thanks!

I can almost be certain it’s the fuel pump. Replaced it and it will solve the problem....
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Thanks for all the valuable input.

 

It’s a Suzuki Swift Sport with 120k millage.

 

Throttle body was cleaned recently less than a month ago as it was the first troubleshooting point. Second was the MAF sensor, replaced it.

 

So far I have yet tested the ignition coil. However spark plug is in good condition and wasn’t overtighten.

 

Next I would be looking into ignition coil and/or fuel pump.

 

Recently have some intermittent starting issues as well. Can hear a click but nothing comes on. Battery seems to be an unlikely culprit as voltage and health indicator is in green condition

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The battery can still be bad despite the "Green" indicator. I have one recently like that (unable to fully charge) and replaced it.

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Do not assume the 4 ignition coil is functionally properly . 1 bad coil can cause sudden drop. Most workshop will have the basic computer scan tool to check the ignition coil if functional properly else error code indicating which coil kaput . If “rough idling “ still appears and u have done the throttle cleaning and new spark plugs. ...... Fuel Pump is the culprit...

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Supercharged

I had a different car and had similar issue before. what happened for my case was the ignition sensor was faulty.

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Twincharged

Thanks for all the valuable input.

 

Itâs a Suzuki Swift Sport with 120k millage.

 

Throttle body was cleaned recently less than a month ago as it was the first troubleshooting point. Second was the MAF sensor, replaced it.

 

So far I have yet tested the ignition coil. However spark plug is in good condition and wasnât overtighten.

 

Next I would be looking into ignition coil and/or fuel pump.

 

Recently have some intermittent starting issues as well. Can hear a click but nothing comes on. Battery seems to be an unlikely culprit as voltage and health indicator is in green condition

Have the exact same car but much lower mileage. No such problems yet. How long has this been happening? Brand of petrol used and octane?

 

Try changing petrol brand and octane? Using 95 still has a very very slight ping at times.

 

How old is the battery? Any parking camera? How do you test the battery?

 

Hear click and nothing happens is unlikely to be fuel pump. Even with faulty fuel pump, the car will always crank.

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Better bring back to where you service it. Seems like your engine is going into a stall and it choke itself back to life. Probably the spark plugs or the MAF sensor but nobody can be sure. Just get it rectified by mechs.. we can only play guess work here. 

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(edited)

Have the exact same car but much lower mileage. No such problems yet. How long has this been happening? Brand of petrol used and octane?

 

Try changing petrol brand and octane? Using 95 still has a very very slight ping at times.

 

How old is the battery? Any parking camera? How do you test the battery?

 

Hear click and nothing happens is unlikely to be fuel pump. Even with faulty fuel pump, the car will always crank.

Been using both SPC and Esso 95

 

Battery age 2 years old. No parking camera, only dash cam which only operates when I am driving.

 

No ICE. Basically no additional accessories to drain power.

 

I took this vehicle over for a couple of months and basic servicing and ATF was changed. Now I suspect they are using the wrong ATF.

 

By the way, when the ac is on, all the symptom is reduced by half.

Edited by Goldenvodka
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Thanks for all the valuable input.

 

It’s a Suzuki Swift Sport with 120k millage.

 

Throttle body was cleaned recently less than a month ago as it was the first troubleshooting point. Second was the MAF sensor, replaced it.

 

So far I have yet tested the ignition coil. However spark plug is in good condition and wasn’t overtighten.

 

Next I would be looking into ignition coil and/or fuel pump.

 

Recently have some intermittent starting issues as well. Can hear a click but nothing comes on. Battery seems to be an unlikely culprit as voltage and health indicator is in green condition

 

last time my inline six 2.2 litre engine same and it is jumping like frog [:(]

 

go back to AD then replace the faulty ignition coil  [bigcry]

 

was 2004 and paid almost 500 cos warranty dont cover wear and tear  :a-m1524:

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Twincharged

Been using both SPC and Esso 95

 

Battery age 2 years old. No parking camera, only dash cam which only operates when I am driving.

 

No ICE. Basically no additional accessories to drain power.

 

I took this vehicle over for a couple of months and basic servicing and ATF was changed. Now I suspect they are using the wrong ATF.

 

By the way, when the ac is on, all the symptom is reduced by half.

Try orig Suzuki oil.
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