HELP: Erratic Idling

[meg_omen]

bros and sifus... need your help and expertise in this matter...

Problem:
- Erratic idling.
- Engine ‘hesitate’ if rpm below 2500, onward acceleration still responsive.
- Idling and ‘hesitation’ worse when a-cond is on.
- Fuel consumption increase to RM65 = 440km (previously reach 500km)

History:
Day 0
- Change coolant (Toyota OEM), afterwards running in is okay.

Day 1
- Starts car, felt the car jerking… bad idling, felt like the spark plugs wet.
- Check and clean the plugs, still the same. Cannot continue checking cause need to drive to Melaka.

Day 2
- Still the same even after driving to Melaka and back.
- Check and clean the ‘plug hole’, replace new spark plugs… no changes.

Day 3 – 5
- Found in the Net, possibilities are
o vacuum leaks
o idling control valve
o vacuum sensor
- Few days already checking from connector to wiring…if any loosen.
- Suddenly, unplug vacuum hose at TB and then plug back… all okay. This hose are from one of the vacuum sensor… circle in red.
- Let the engine running for a while, then after switching the ac on, problem starts again.

Day 7
- Check and clean the valve at the TB (red circle)… no changes.
- Change the o-ring for AFPR… no changes.
- Change all vacuum hose to silicon (ayam brand)… no changes.



Questions:
1- How to know is the ICV is okay?
2- What is the vacuum sensor for… red circle and blue circle?
3- Where can I get this vacuum sensor (red circle)? Anybody have ‘left-over’ from their conversion, give me the price? The sticker at the sensor shows…
DENSO
Sensor Assy. Vacuum
89420-12070
100798-2563
5V
4- Any other possibilities? Really confused already…please help?

Note:
- Spark plug are ‘side-gapped’, including this new change already using 4 sets.

Thanks.

 

[EFN]

Frenm dun forget your car have O2 sensor which might not be giving your ECU a proper reading and thus screwing things up.

Your model of 4A-FE have O2 sensor which is connected somewhere at the exhaust manifold - you might want to pull it out and do some cleaning using WD40.

Could be oso that the Vacuum (MAP) sensor is not in a good shape anymore. If there is a need to replace this, you can get them easily at kedai potong (use Blacktop MAP sensor oso can)

 

[meg_omen]

MAP sensor

thanks bro for fast reply, but where is the MAP sensor. Cause most of information I get from 4AGE manual... couldn't get 4AFE one.

anyway, the O2 sensor will be the next in my list but need to wait until weekend. not enough tool to complete the job.

what's the purpose of the 2 vacuum sensor, red circle - 1 hose to TB & blue circle - 1 hose to TB and another to somewhere underneath the inlet manifold. which one is the main and which is the for the ac?

haiya...still a lot of thing to learn. help....

 

[meg_omen]

Help....

bros and sifus... need your help and expertise in this matter...

Problem:
- Erratic idling.
- Engine ‘hesitate’ if rpm below 2500, onward acceleration still responsive.
- Idling and ‘hesitation’ worse when a-cond is on.
- Fuel consumption increase to RM65 = 440km (previously reach 500km)

History:
Day 0
- Change coolant (Toyota OEM), afterwards running in is okay.

Day 1
- Starts car, felt the car jerking… bad idling, felt like the spark plugs wet.
- Check and clean the plugs, still the same. Cannot continue checking cause need to drive to Melaka.

Day 2
- Still the same even after driving to Melaka and back.
- Check and clean the ‘plug hole’, replace new spark plugs… no changes.

Day 3 – 5
- Found in the Net, possibilities are
o vacuum leaks
o idling control valve
o vacuum sensor
- Few days already checking from connector to wiring…if any loosen.
- Suddenly, unplug vacuum hose at TB and then plug back… all okay. This hose are from one of the vacuum sensor… circle in red.
- Let the engine running for a while, then after switching the ac on, problem starts again.

Day 7
- Check and clean the valve at the TB (red circle)… no changes.
- Change the o-ring for AFPR… no changes.
- Change all vacuum hose to silicon (ayam brand)… no changes.



Questions:
1- How to know is the ICV is okay?
2- What is the vacuum sensor for… red circle and blue circle?
3- Where can I get this vacuum sensor (red circle)? Anybody have ‘left-over’ from their conversion, give me the price? The sticker at the sensor shows…
DENSO
Sensor Assy. Vacuum
89420-12070
100798-2563
5V
4- Any other possibilities? Really confused already…please help?

Note:
- Spark plug are ‘side-gapped’, including this new change already using 4 sets.

Thanks.

anybody can help? anybody have the above vacuum sensor?? tolonggggg...