What can cause slow acceleration?

Answer 1

I had a very similar problem, my car (VW 4 Cyl) was fine until it warmed up. Then, slow sawtooth like acceleration and rather poor performance along with high gas consumption (low mpg). I figured at 200k the O2 sensor needed replacement and voila, it works like a charm now. O2 sensors are critical in that they advise the engine how rich or lean to run the mixture and if they ill-advise, due to fatigue or damage, the engine likely runs too rich which leads to unburned fuel going through to the catalytic converter and starts to fry it.

You can replace it yourself very easily just make sure you get a direct fit original part.

I would check for a plugged fuel filter or plugged exhaust system.

Also consider getting yourself a service manual for your car, as it often has troubleshooting tables for many kinds of problem.

As mentioned, plugged converter. Also there can be a transmission related problem, a drag possibly coming from a wheel (such as e-brake on or stuck, calipers not releasing. Too much fuel or too little fuel getting to the combustion chambers which can be a mechanical kind of problem like a fuel leak. worn plugs or a engine management control problem like an oxygen sensor or a throttle position sensor. Check the accelerator cable to see if it is excessively stretched and not allowing the engine to achieve maximum acceleration.

Also could be a fuel pump which is beginning to go. Thus the fuel is not regulated properly and affecting the usual acceleration. Lack of maintenance such as spark plugs, plugged filters, carbon build up.

Higg's wave.

Injectors. Get injector flush and change fuel filter.

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This is a VERY common cause for sluggish cars seems even more common in deisels but not exclusive to them. The Air Flow Meter also known as maf sensor (Mass Air Flow) dont replace it right away though. First of all remove this component from the engine bay, it is normally located between the air filter box and the throttle body, then clean the element inside with some carb-cleaner (or air intake cleaner), replace the unit and give it a go.

FIRST, KEEP IT SIMPLE

Totally plugged fuel OR air filters can also cause this. Fuel and air filters are crucial maintenace items and are very cheap to replace. Before you spend big bucks on ANYTHING make sure both filters are replaced. Many expensive in-tank fuel pumps are ruined by a plugged fuel filter. The pump simply burns out trying to push fuel through a plugged filter. Many technicians that have worked for me have completed a $400.00 - $600.00 fuel pump replacement just to find only a plugged fuel filter. VERY embarrassing!!! Bestaluck

Just a couple things I have seen.

First off, if you are dealing with a vehicle that does not have computer controlled ignition timing then it would be a very good idea to check that the timing is set correctly.

Secondly, I have seen several occasions where someone has installed a timing belt one tooth off. Most vehicles with a timing belt off will idle and run as normal, but a very significant loss of power will occcur.

Third, be sure that the engine is the source of your car's sluggish nature. It could be a transmission issue. On many newer vehicles with computer controlled transmissions the transmission has a safe mode if there is a problem with the control systems. This will cause the transmission to start in second gear making the car feel very sluggish.

answer

i would check your air mass meter they give loads of trouble with modern cars .it could also be your clutch slipping or your plug leads could be breaking down under load