Hey guys, need all expert input on this issue. Been trying to trouble shoot this problem for the past week or so. Car lacks acceleration, it feels like the car is in 3rd gear or something trying to accelerate from standstill. It's a auto blm. Either no response or climbs really slow. Car smooths out above 2k RPM.

I know the throttle is opening properly, I've got a vacuum meter, when pedal is press the vacuum drops as it should but car was not accelerating or accelerates really slow like in high gear. Above 2k RPM the car behaves quite normal albeit feels a bit more underpowered than usual. No jerking etc, cars just wont go.

So far I cleaned the throttle body, changed the spark plugs, engine oil and gearbox oil was changed recently. Just serviced the brakes and change fan belt. What else could be causing the problem? Any input? Thanks a lot guys.

This post has been edited by -storm-: Apr 8 2013, 07:26 PM

Maybe your A/T stuck in higher gear so not dropping to 1st gear when stop/very slow speeds, hence your acceleration is very sluggish. I experienced that once in my Livina but then after stopping for several hours at home, it's back to normal ever since. I asked the SC to check and they said they reset the ECU and there's no error code or anything suspicious. Anyway the problem never comes any more.

Is it the same in L gear?

Same in L gear, sometimes the problem does not happen, but getting more and more frequent.

Throttle body response normal (according to vacuum gauge), happening as well in L gear means it's probably not gearbox/TCU problem.

In this case I suspect there is something wrong with the torque converter causing slippage during acceleration.

This post has been edited by dares: Apr 9 2013, 07:36 AM

u might need to check ECU to diagnose c got any erro code on Powertrain. as wat dares said it might be TC coz old skool auto mostly problem are from TC. btw its ur gear box making sum pitch sound?

mostly auto TC will have problem 1st except u shift to R on highspeed thn thts other story~!

what car?

i've got scanner, no error code found. saga blm auto. I suspect fuel pump though. gearbox not making any abnormal sound. does weak fuel pump cause this symptoms?

This kind of vacuum gauge?



To me you sound like a Ah Beng modding kaki.
What else you had modded? Probably due to Ah Beng-ing gone wrong...

please define ah benging gone wrong? or you are just a troll? obd scan can read vacuum pressure as well.

This post has been edited by -storm-: Apr 9 2013, 06:12 PM

did another scan just now found an error code, it's a grey code though, P0170 fuel trim, bank 1.

http://www.obd-codes.com/p0170

thanks bro, but anyone familiar with proton obd code specific? I guess i've to go back to proton and kena potong.

Some SCs don't charge you for OBD fault code check, do ask before you proceed.

OBD II codes are standard and it is the same for all cars using OBD II and it applies to you too. This error code is related to air fuel ratio and the ECU has reached it's limit of controlling fuel ratio. The ECU relies on the air flow sensor and/or O2 sensor to properly calculate the amount fuel needed to match the amount of air being sucked into the engine.

I had this issue when my air flow sensor went bonkers and engine was misfiring on all 4 cylinders (I had error code P0301 Cylinder 1 Misfire Detected P0302 Cylinder 2 Misfire Detected P0303 Cylinder 3 Misfire Detected P0304 Cylinder 4 Misfire Detected too). Replacing the air flow sensor fixed the problem immediately as it was a common issue in my car (in fact I'm on my 3rd air flow sensor). Your issue could be this or it could also be O2 sensor.

Is your engine misfiring (indicates mixture too lean) or are you getting bad mileage (rich condition)? Both of these conditions are related to your error code.

This post has been edited by sleepwalker: Apr 9 2013, 10:02 PM

Saga BLm dont have air flow sensor, Only Tmap sensor. I'm currently suspecting my o2 sensor, mileage was pretty bad on one particular tank of petrol last week, rm30 i manage 80km, before this problem my worse was rm30 per 120km.

Funny thing is my 02 sensor voltage reading is within specs, it's jumping back and forth between 0.7v and 0.1v.

I tried unplugging the 02 sensor and taking the car for a spin, car totally no power and shudders and throws a lean error code. Plug back in cleared the code and it was back to square one of this problem although still drivable turtle speed. Tmap going bad?

This post has been edited by -storm-: Apr 10 2013, 01:38 AM

MAP or MAF, they both do the same thing and that is to calculate the amount of air being sucked into the engine so that the ECU can use it to calculate the amount of fuel needed. MAP does not go bad as fast as MAF but still a possibility. If the problem is always there and easily reproduced, it shouldn't be too difficult for any SC to rectify the issue.

I used to have the same problem. stuck at third gear. end up its the sensor at gearbox (thats what they told me) spoiled. replaced both sensor, cost me about rm 700 =( but i'm driving hyundai though.