Gy6 TPS and oxygen sensor

[4 stroke power]

I just bought a new oxygen sensor for the second time and I am waiting for a new TPS (throttle position sensor) for my Chinese gy6 50cc euro4. The first time I installef both and drove and then ended up with both parts defective. But this time I want complete control over how it should be done when I have mounted the parts. What should I do after installing the parts? Should ECU / ECS be restarted before first startup? Should the engine be idling high or low? And how long? I hope someone can help me because I'm not very good at electrical work.

[scooter7878]

Don't really know much about computer controlled scoots but Im a diag tech in automotive it can't hurt to do a reset of the ecm on a car if u remove negitive battery cable and hold it touching the positive terminal it will deplete whatever excess voltage left and most likely clear the ecm memory. I would expect it to run too different I would think it may idle sparadic for a few minutes until it relarns the idle and clears out

[GrumpyUnk]

Having O2 and TPS failures can be caused by a few things. One is poor quality from the factory. A second is the voltage being supplied is not controlled or regulated properly. Most TPS use a 5V 'reference' voltage, a fixed voltage to have for comparison to the produced signal. The O2 sensor may have 'heaters' that make it start to work earlier. If either is fed unregulated DC or un-rectified AC, you may fry the sensors.
I would suggest checking that your charging system is doing its job before installing another set of sensors.
tom

[4 stroke power]

Scooter7878

I have tried that today but the scooter wont start. I will try to start it again tomorrow after charging the battery

[4 stroke power]

GrumpyUnk

Both sensors are tested and work fine anz everything else is also good

[GrumpyUnk]

Not sure what is being discussed, the install would be to remove the old parts, disconnect first... then install the new parts and reconnect to the wiring harness. Start the engine. Nothing special, no need to have anything turned on or running. You do not want things to be running when installing parts of any kind.
Once installed, if you have a meter, check that the voltages specified in the wiring schematic/diagram are present and proper. For example, turn the key to ON, and check that battery 12V is present at the locations where it is supposed to be with the ignition switch ON. If missing, chase down that problem.
The O2 sensor can be a 'one wire', which means its case(threads) are grounded to the battery through the exhaust pipe, engine block, and wire to the "-" post of the battery. Make sure the engine is grounded. The ECM(computer) will also be grounded. If you checked ohms between the computer ground spot and the O2 sensor ground, they should be minimal. For example. The TPS will have a ground and at least one wire, which should vary in resistance as the throttle is opened/closed. Fancier will have more wires, and two criss-crossed variable resistors, one goes up, the other going down(in resistance) as their wipers move from closed throttle to WOT. You should be able to measure the ohms in the TPS to insure it is producing varying resistance. Again, it must have a good ground or its reading/output will be useless(it won't work).
So what is happening? No start? Start/stall? Start and won't increase rpms? Low power? Poor acceleration?
Read your messages, and there's not much there explaining what you are doing... AFAICT
tom

[4 stroke power]

GrumpyUnk

Everything you mentioned have been tested with multimeter and everything is working. It wont start at all - that is the issue.

[jackrides]

I'm obviously behind the times. When ecu & FI work, how do you like the difference?

[4 stroke power]

Jackrides

I don't understand your question

[GrumpyUnk]

Jackrides is asking how well the EFI system works compared to a carbureted system. EFI generally gives proper fuel:air ratio from idle to WOT, compensating with the information from the O2 sensor as to whether the squirt of fuel from the injector matches the incoming airflow. It also makes for better coldstart operation as it can enrich the mixture until the engine reaches operating temperature so one can drive off without stumble with a cold engine.
So, do you have spark when cranking? Use a spare plug resting on a grounded surface, and connect the plug wire to the spare plug, crank the engine to start. You should see spark jumping the gap from center to side electrode.
Or to test fuel presence, squirt some carb cleaner into the throat of the carburetor, crank to start. If it now starts and runs for a few seconds, you have a fuel delivery problem and the spark(ignition) system is functional.
Have you done these? Last test is a compression test to insure the rings and valves are at least reasonable or good enough to allow a normal engine without other problems to operate(run). Check compression.
tom