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Old 18th June 2008, 20:31   #1
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Unhappy Unsteady RPM with AC on ?

hi buddies,
i had purchased an SX4 in june last year. The car was going fine, but one day with an intention to reset the ECU settings, i disconnected the battery connections. That however, turned out to be very different.

When i reconnected the terminals after 10 mins and fired up the engine, the RPMs rose, as they normally do from 0-1700 revs, and then the RPMs died back to zero and the engine went off. I thought maybe i should just try it one more time and keep accelerator depressed a little so that the engine doesnt shut off and i drove for around 30 mins around town. But everytime i depressed the cluth to change gears or come to a complete halt, the engine would shut off (and yeah, the brakes went useless ! OMG !!).

I repeated this entire process again, thinking that the ECU may regain the proper settings, but to no real positive effect. Hence, took the car to my M.A.S.S.

There the M.A.S.S wizkids gave in their opinion straight on just by listening to me "sir, petrol ganda hai, isliye injectors and fuel filter choke ho gaya hai". I gave a real good glance but by that time one chump took out some fuel from some pipe in the engine bay, and showed it to me. I couldn't make out anything, but they affirmed that the sample was the dirtiest they had ever seen.

i had no choice so they took in the car for a day and cleaned up every thing injectors and filters and tuned the engine. Next day the car was delivered. All RPMs were stable but the idling RPM was very low, although the engine didnt shut off. Complaining about this was, well, useless. "Its perfectly fine sir..its just your feeling".
Bill : INR 2200.

I drove off, but the very next day when i fired up the engine the same story, the engine shut off every time i cranked up. took it again to that M.A.S.S.

Again the very same reply, "petrol fir ganda hai sir". This time i had taken my father along, and on hearing this he impulsively slapped the mechanic right across his face. OMG, there was such a chaos after that.

We argued that if this car required such clean petrol then maruti should supply imported petrol barrels to all SX4 customers because i had filled in from one company owned petrol bunk (highly reputed).

The slap was promptly heard loud and clear everywhere !

I asked to strap on the ECU scanner and check the reading and if required remap the ECU again to factory settings. They promptly did that.

Bill: INR 00.00

Took the car the next day, it was as good as new nothing wrong now.

But later, i discovered another RPM problem. Whenever i switched on the AC, hot start or cold start, the RPM dipped very low to about 500-600 revs but the engine didnt shut off completely. Also the RPM keeps fluctuating b/w 500-900 RPM, which is very annoying and jerky.

Guyz pls help me on this, i dont want to go back to the whizkids !

Thanks in advance, sorry the very long post !!


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Old 18th June 2008, 20:50   #2
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What are the RPM reading while at idle, AC ON and AC off figures? Cold and Warm? Are these constant? Answer these.

On the other hand, slapping another individual is not a very nice thing to do. You can always escalate the problems to the dealer Manager in charge or Maruti Udyog instead.

Last edited by Jaggu : 18th June 2008 at 23:27.
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Old 18th June 2008, 20:58   #3
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You may want to get your fuel injectors tested. This is how it behaves especially if one of them is not working properly. Also check your RPMs at idle. You should see a very minimal fluctuation but surprisingly you don't feel these fluctuations while you drive. With the AC on it may be a different story.
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Old 18th June 2008, 22:50   #4
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Quote:
Originally Posted by Vishesh View Post
This time i had taken my father along, and on hearing this he impulsively slapped the mechanic right across his face. OMG, there was such a chaos after that.

The slap was promptly heard loud and clear everywhere !
I am shocked to see those statements, and i hope they didn't messup your ride in retaliation !!
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Old 18th June 2008, 23:16   #5
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As somebody already pointed out do get your injectors checked. If the idle RPM keeps jumping up and down with the AC on it most probably is because one of the injectors is chocked.
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Old 18th June 2008, 23:22   #6
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Did Slapping the guy resolve the issue, Some cars are sensitive to certain fuel brands..!
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Old 19th June 2008, 02:01   #7
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You said it was working fine before you unplugged the battery to reset the ECU. Therefore it is not the injectors or at least this is highly unlikely. It is still the ECU. Take it to another dealer, tell them your problem and ask them to reprogram or "reflash" the ECU. Do not take your father unless you have to make a second trip there.

And, since everything was working fine, in the future,
"If it ain't broke, don't fix it."
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Old 19th June 2008, 10:17   #8
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Post ISA may be the culprit !

Howdy ,
There is something called an ISA ( its an ' idle speed actuator device ' a small motor with butterfly type of flap ). iTS ATTCHED TO YOUR THROTTLE BODY & nonoptimal functioning of ISA can result in the problem that you face. Injectors trouble very very unlikely
fIRST TRY AND SCAN THE VALUE OF ISA normally with engine idling and then try switching on the AC.
If the value is lower than the reco. you need to change it or try servicing it ( read decarbonizing with some spray ) This may help.
Try and let me know if it did or not. If its ok and has to be ruled out then you need to consider some sensor as the possible culprit.
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Old 19th June 2008, 10:45   #9
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Also just check the vacuum hoses for the AC they could be disconnected or have a leak..but like Dan says if it was working earlier than it should now too..unless your "reflashing" messed up the ecm permanently which is unlikely
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Old 19th June 2008, 19:07   #10
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Did your father inform the service manager that you had initially disconnected the battery connections to reset ECM ?

Before taking any action against anyone, I think that you should have informed Maruti about this.

You have to tell the entire story to doctor and then he can pinpoint and solve the problem.


Quote:
This time i had taken my father along, and on hearing this he impulsively slapped the mechanic right across his face. OMG, there was such a chaos after that.

We argued that if this car required such clean petrol then maruti should supply imported petrol barrels to all SX4 customers because i had filled in from one company owned petrol bunk (highly reputed).

The slap was promptly heard loud and clear everywhere !
Did your father inform the person whom he slapped that you had disconnected the battery for resetting. Did slapping solve your problem ?
I hope that they have not messed up with your car for this.

Trust me they can do this, I have personal experience.

Last edited by aaggoswami : 19th June 2008 at 19:08.
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