Hi guys

Would really appriciate if someone could please give me some advice on these EFI systems please, my 1997 Atos (South Africa), hesitates only when you slightly touch the gas pedal, (Neutral & all gears). when keeping the accelarator slightly pressed the car bogs down, and then picks up normally after lets say 2200rpm?. So pull away is difficult. And also on the highways in any gear when trying to keep the speed steady, the car will bog down as if i switched the ignition off, theres like a (flat spot) if i can call it that on the gas pedal after this happens, then all of a suden she goes again. Could this be my TPS Sensor that is faulty, or maybe another sensor? crank speed sensor? MAP sensor? please guys this is really anoying
(please mind my english as i am actually Afrikaans speaking)

 

If you believe it to be the TPS sensor then you can back probe the connector with a volt meter to determine if it is functioning properly
The voltage should vary with the position of the throttle

If you believe it to be the crank sensor then you will need to inspect the sensor and it's position
When the sensor is a bit away from the crank which gives it the signal, the signal can be too weak for the ecu to read and the spark and fuel will not function properly
Unfortunately, it isn't as easy to test .. it needs to be taken out and bench tested and check the place where the sensor is seated (sometimes dirt or metal shavings clog the area)

It could be clogged fuel injectors
Then it would take a couple of bottles of fuel injector cleaner to fix

A bad or clogged (filter) fuel pump can also cause similar problems

Check the air filter to make sure it is clean enough to run the engine

Good luck to you