Can't rev when running

[madduck]

The engine can rev properly in idle.
Can't rev past 1800 RPM kapag paakyat ang road. Hindi tuloy makahatak.
Can't rev at all kapag naka ON ang aircon.
RPM drops kapag bumabagal.

Pleas help. Car is Sentra, GA16DNE.

[siopaonatoasted]

Fuel filter.

[madduck]

Changed my fuel filter last April.

[vinj]

Perhaps it could be MAF (Mass Air Flow) sensor issue. Try having your throttle body opened and cleaned along with the MAF sensor. A diagnostic engine scan should help.

[madduck]

I've cleaned the throttle body, last month, pero nilinis ko lang ng nakakabit pa. I'll clean MAF, thanks sir!

[oj88]

Sounds like it could be on limp mode. Is the CEL on? Have the engine computer checked for DTCs.

[jick.cejoco]

The engine can rev properly in idle.
Can't rev past 1800 RPM kapag paakyat ang road. Hindi tuloy makahatak.
Can't rev at all kapag naka ON ang aircon.
RPM drops kapag bumabagal.

Pleas help. Car is Sentra, GA16DNE.

what year is your car? how many miles? what was the last thing done to it? did the symptoms start after you refueled? is the exhaust system clogged? do you have throttle by wire? what is the engine vacuum measured at the intake manifold at idle speed?

[madduck]

what year is your car? how many miles? what was the last thing done to it? did the symptoms start after you refueled? is the exhaust system clogged? do you have throttle by wire? what is the engine vacuum measured at the intake manifold at idle speed?

year 2000
last thing done, replaced distributor o-ring
no, not after refuel.
don't know if the exhaust is clogged.
not sure what is throttle body by wire.
I don't know the engine vacuum

[jick.cejoco]

year 2000
last thing done, replaced distributor o-ring
no, not after refuel.
don't know if the exhaust is clogged.
not sure what is throttle body by wire.
I don't know the engine vacuum

have the ignition timing checked and maybe adjusted.



chances are the ignition timing is late and should display lower than 18 inches of mercury vacuum at the intake manifold at idle speed

[madduck]

have the ignition timing checked and maybe adjusted.



chances are the ignition timing is late and should display lower than 18 inches of mercury vacuum at the intake manifold at idle speed

how would i know if the ignition is adjusted correctly? Thank you.

[jick.cejoco]

how would i know if the ignition is adjusted correctly? Thank you.

you can have this done in different ways:

1-using a scan tool with the engine running and go to engine parameters

2-using a stroboscopic timing light aimed at the timing marks after all the prerequisites are satisfied

3-if the two above are unavailable, you can use an inexpensive engine vacuum gauge connected to a non ported vacuum source on the intake manifold

4-if the shop you have been going to is incompetent or has incompetent "mechanics", go to another shop with equipped, trained and experienced technicians