Hello, I've got a strange problem with my tachometer, rpm needle is vibrating/ shaking when I hold my foot steady on throttle, not by much but i can see it. I've done some job myself but nothing helped. I've cleaned maf sensor, throttlebody aslo I've replaced a set of sparkplugs, new synthetic oil and filters. Car is relatively new. Toyota Avensis 2017 (European model not avaliablein the US) , 6 speed manual with 1.8 2ZR FAE engine 147HP, milage is quite low, around 45k miles. No trouble codes, car drives normally. Maybe air leak, I hope that my timing chain is ok. Maybe some sensor going bad? Or tachometer/ instrument cluster/ electrical problem. I've posted a video on YouTube where you can see what I mean. It happens in neutral and under load also. No idea what is going on. https://youtu.be/PNe8mpWB6RE
All the Best.
shows 1g/s of air flow. Is it OK
just make sure you keep air filter , intake, throttle body, MAF sensor clean.
On idle mass air flow shows 1g/s of air flow. Is it OK for 1.8 2zr afe engine? I think that 1.8 engine should have around 1.8g/s of air flow on idle.
The displacement volume in grams on the MAF data is kind of a rule of thumb. It also depends on altitude and temperature, since those change the amount of air ingested by the engine. My 1999 Ford Ranger reads around 4.85 g/s and the fuel trims are within 2-3% of perfect, it's a 3.0L. If your fuel trims, particularly Long Term Fuel Trim (LTFT on the scanner) are close to 0, you're good.
Have you looked on your scan tool to see what the PCM is reading the RPMs as? My cars all fluctuate within 20 RPM of the target speed, which I would call normal.
Yes I did check rpm on scan tool. Rpm bounces +/- 10-25 rpm on idle. One more thing, In neutral if I put my foot on gas and for example I will rev the engine to 2k rpm on tahometer it will still fluctuate in range between 2000- 2030 rpm i can't keep stable 2k rpm while holding my foot steady on the throttle, is that normal? Tomorrow I will check LTFT.
I lost my chance to edit 😕 I meant that in neutral if I will rev the engine to let's say to 2k rpm on tacho, my scan tool rpm will show bounce between 2000-2030 rpm, is that normal? I can't keep steady 2000rpm while holding my foot steady on the throttle in neutral. It will go back and forth between 2000-2030 rpm. Is that normal engine operation?
That's pretty normal, I would say. It's only a 1.5% variation.
So maybe my problem is in the tacho itself or it is some kind of electrical issue ❓ or my tachometer lost its inertia and it's showing 1:1 reading form the ecm 😆 sorry for my English, I hope all of you can understand what I mean.
Hello!
If it is just that and everything else is OK, I would not worry.
Good luck!
Thanks for your reply BTW. Sorry for my English it's not my native language. One more question. I've hooked up BT obd2 scanner. On idle mass air flow shows 1g/s of air flow. Is it OK for 1.8 2zr afe engine? I think that 1.8 engine should have around 1.8g/s of air flow on idle. Correct me if I'm wrong.
Perhaps @dan knows
Put the car in gear and then read your MAF reading.
@yaser he has manual gearbox. Once you put into a gear and release the clutch pedal, the car starts moving. It would not be safe.
I've checked my long fuel trim on obd II scanner it's close to 0, so I guess I'm good.
I was wondering, if I unplug MAF sensor while engine is running it will cause engine to turn off?
Funny thing, it was raining so humidity after the rain is quite high and suddenly my tachometer needle is stable no erratic behavior, what could this mean? Loose wiring connection?