Chung Myung

Well you'd have to find the factory fuel pressure spec somehow to do that... if you're based around Kandy Nandana motors and Knight auto works have been recommended by the forum members before It can't hurt to replace the fuel filter too if you haven't done it already when you replaced the pump.

1. Check for Additional Vacuum Leaks Since you replaced the intake manifold gasket, there's still a chance of leaks elsewhere: PCV valve and hoses – A stuck-open PCV valve can cause excessive air intake. Brake booster hose – If there's a vacuum leak here, it could cause hesitation. Throttle body gasket – If not sealed properly, it can create an air leak. 2. Throttle Body & MAF Sensor Cleaning Throttle body – If it's dirty or sticking, it can cause poor throttle response. Clean it with throttle body cleaner (not carb cleaner) and do an ECU throttle reset if needed. Mass Air Flow (MAF) sensor – Even if the live data seems normal, a dirty MAF sensor can cause intermittent issues. Try cleaning it with MAF cleaner. 3. Check Fuel Pressure Again Since replacing the fuel pump motor helped, ensure the fuel pressure regulator and fuel filter are working properly. A weak regulator might not deliver enough fuel under load, causing hesitation. 4. CVT or Transmission Issue? The part where you mentioned, "engine revs around 3000 rpm but doesn't pull the car enough relative to the rpm" suggests a possible CVT transmission slip (if your car is CVT). Check CVT fluid condition – If it's dark or burnt-smelling, consider changing it (but be cautious with CVT fluid changes if it's never been done before). If it's not a CVT, check for clutch slippage in an automatic or manual gearbox. 5. Exhaust Backpressure Issue? You mentioned: "feels like the engine is trying to push away air." If the catalytic converter is partially clogged, it could cause power loss and hesitation. Try removing the upstream O2 sensor (temporarily) and see if power improves. Check for unusual exhaust smells, rattling, or excessive heat from the catalytic converter. Next Steps: Spray test for vacuum leaks (carb cleaner near intake components). Clean throttle body & MAF sensor. Check fuel pressure at high RPMs. Check transmission behavior (if CVT, test for slip). Test for a possible clogged catalytic converter. -ChatGPT

It's not mine actually, it's my brother's but I'll post a few pictures if he's okay with it 👍 So... the best recommendation would be synthetic oil from a reputed brand changed every 9ish months, right? if you were the owner, would you change to 12-month synthetic 5W30 oil changes or stick with 6-month conventional 10W30 changes? ( imagine those 2 are the only options you've got and both oils are from a reputed brand )

Thank you for the detailed reply 🙏 No, as far as I can see/hear the engine runs smooth. Previous owner reported no oil burn. There was a slight ticking noise (lifters? valves?) when accelerating between 2000-3000RPM (previous owner hadn't even noticed so the sound could've been there since the car was brand new) which went away after the first oil change done by the new owner with Mobil 1 Advanced Full Synthetic 5W30. Yes, going forward it'd be either Mobil or Liqui Moly (if went the synthetic route), purchased directly from the authorized agent (McLarens or Semini Motors) The cost is about the same if oil gets changed twice a year with conventional oil or once a year with synthetic. Well let's just say if it is a choice between engine longevity and environmental conservation the clear choice would be the first 😅 But I reckon squeezing as many kms as possible from an engine helps the environment too considering the environmental impact of manufacturing new engines 😁

Which would be the better option for a Toyota Corolla 141 (2008) that has been driven using exclusively conventional engine oil by the previous owner? The mileage is 64,XXX kms, purchased from the owner who bought it brand new so the mileage is accurate. Max distance the new owner would be driving is 250-300Kms a month, that too short distances. What would be the better option for the new owner, continue using conventional oil ( Castrol 10W30) and change it every 6 months or switch to full synthetic (Mobil 5W30) and change it every 12 months? (As the car won't be driven 5000kms even in an year) The new owner prefers to use synthetic because the car is very noticeably quieter when accelerating with synthetic oil compared to conventional but wonders if it's pointless and if it could even be detrimental compared to using conventional oil because of the longer service interval. Thank you in advance.