Idle RPM @ 2000

[talharahim]

Hi,

My efi mechanic has set the rpm to 2000 because my ecu is not working and pushing up rpms when ac is on. When ac is on it drops to 1200 idle I want to know if that can cause wear and tear to the engine? and what about fuel economy

car is city 2000

[Jeep_junkie]

Hi,

My efi mechanic has set the rpm to 2000 because my ecu is not working and pushing up rpms when ac is on. When ac is on it drops to 1200 idle I want to know if that can cause wear and tear to the engine? and what about fuel economy

car is city 2000

Did you take the car to a mechanic or a butcher?? Find a proper mechanic first. No grease monkey worth his salt would suggest a repair as the one done to your vehicle.

And to answer your question, yes, idling any faster than the engine's preset idle speed will result in poor fuel economy and accelerated wear.

[talharahim]

at the moment there is no solution available, i have taken the car to every mechanic

[a_n_memon88]

at the moment there is no solution available, i have taken the car to every mechanic

Boy its not your cars ecu thats faulty but there is a load sensor in your cars throtle body that or distributor or carburator I am sorry but I am not confirm exactly what system your car uses. But that sensor is used to increase idle rpms and change the ignition timing as the load on the engine increases, that sensor in your case is not working thats why rpms drop. What your idiot mechanic has done is he has increased the idle rpms but wrongly advancing them through carburator. Get the sensor changed first and than get the rpms reset

[talharahim]

Boy its not your cars ecu thats faulty but there is a load sensor in your cars throtle body that or distributor or carburator I am sorry but I am not confirm exactly what system your car uses. But that sensor is used to increase idle rpms and change the ignition timing as the load on the engine increases, that sensor in your case is not working thats why rpms drop. What your idiot mechanic has done is he has increased the idle rpms but wrongly advancing them through carburator. Get the sensor changed first and than get the rpms reset

lad, i have already tried that one, infact changed the whole trottlebody with the new one, the efi electrician said the ecu is not sending current :S:-#

i use ac all the time and 1000 RPM with ac seems fine logically!!??

[Xulfiqar]

This needs to be checked thoroughly, its not just simple load sensor etc or current. The HVAC unit sends signal to the ECU which then relays signal to the compressor clutch magnet relay and the condenser fan relay. If your A/C compressor is working but idle control is not then the wiring to it is either disconnected or wrongly wired up (possible if ECU is shershah maarka ECU as japanese models have differences).

A good competent A/C mechanic can solve this out, or you would need to get to a good electrics guy who understands this wiring.

[a_n_memon88]

This needs to be checked thoroughly, its not just simple load sensor etc or current. The HVAC unit sends signal to the ECU which then relays signal to the compressor clutch magnet relay and the condenser fan relay. If your A/C compressor is working but idle control is not then the wiring to it is either disconnected or wrongly wired up (possible if ECU is shershah maarka ECU as japanese models have differences).

A good competent A/C mechanic can solve this out, or you would need to get to a good electrics guy who understands this wiring.

From what I understood was that this guy's car was idling at certain rpms say 1000rpm and when he switches on the AC the rpm dont rise and with the load of AC compressor the rpms drop below 500rpm, resulting in car shutdown. He went to a mechanic and he increased the idle rpms to 2000 so that when AC is on the rpms dont drop too low. I still see it as a sensor problem.

@OP do the rpms increase when you use other electronics except AC like headlights, fan, audio

[Xulfiqar]

I have seen this problem, the A/C circuit goes through the ECU - which then controls the engine rpm at idle speed to compensate the A/C load.

The idle control itself if three wire has one 12V+ supply and two wires controlling the rotary valve, if the 12V+ is missing the idle wont work.

[talharahim]

I have seen this problem, the A/C circuit goes through the ECU - which then controls the engine rpm at idle speed to compensate the A/C load.

The idle control itself if three wire has one 12V+ supply and two wires controlling the rotary valve, if the 12V+ is missing the idle wont work.

I got it to a competent AC wala at Tariq Road and he called a "competent" ac electrician.. who told me to install carb pump instead of playing with the wire as this is a common issue with the efi cars....

he altered the accelerator wire gauge and installed two additional pump , along with two air pipes

it took them 3 hours to do so, (*during the first real rain in Karachi for 2012)... and now my ac car idles at 900 and with ac it goes to 1000 :D... charged me 1500 for this

[talharahim]

I have seen this problem, the A/C circuit goes through the ECU - which then controls the engine rpm at idle speed to compensate the A/C load.

The idle control itself if three wire has one 12V+ supply and two wires controlling the rotary valve, if the 12V+ is missing the idle wont work.

You are absolutely spot on!!! that is what that competent electrician told me... i am now really pissed on those so called specialist who told me to replace the whole card ...

[Xulfiqar]

I got it to a competent AC wala at Tariq Road and he called a "competent" ac electrician.. who told me to install carb pump instead of playing with the wire as this is a common issue with the efi cars....

he altered the accelerator wire gauge and installed two additional pump , along with two air pipes

it took them 3 hours to do so, (*during the first real rain in Karachi for 2012)... and now my ac car idles at 900 and with ac it goes to 1000 :D... charged me 1500 for this

The ECU also changes ignition timing when the A/C is working to compensate the compressor load. What has been done is a joke at best. If I were in Karachi I would have solved that for you, takes about half an hour inlcuding testing.

[talharahim]

The ECU also changes ignition timing when the A/C is working to compensate the compressor load. What has been done is a joke at best. If I were in Karachi I would have solved that for you, takes about half an hour inlcuding testing.

Can you elaborate?? what effect it will cause as the drive seems to be normal now??

i believe u buddy, trust me here in Karachi most of the mechanics are jokers, butchers i have shown my car to almost every big name in Karachi ...

[Xulfiqar]

You will feel the car accelerate laggy.

[talharahim]

You will feel the car accelerate laggy.

No have not felt any lag

[shahidnoman]

you can contact MR.ARIF at 0213-5385775 he is in defence , he can help you out sure !!

Hi,

My efi mechanic has set the rpm to 2000 because my ecu is not working and pushing up rpms when ac is on. When ac is on it drops to 1200 idle I want to know if that can cause wear and tear to the engine? and what about fuel economy

car is city 2000

[nbahmad33]

Sir can you plz help me, when ever my car ac compressor on rpm initially goes to 1200 or 1300 and gradually comes to normal 900. Altis 1.6 2013. Its fine on highways but in rushy place in city its really hard to stop the car because sometimes its on while break and suddenly i have to move. The original compressor has been already replaced by the 01st owner and i am the 02nd. I drove AT vehicles but 01st time i am experiencing this problem. Plz help