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-   -   Strange Behavior of my ALTO, Expert's Advice needed (https://www.team-bhp.com/forum/technical-stuff/47263-strange-behavior-my-alto-experts-advice-needed-8.html)

Hi Amit, I'll get back to you with the recommended procedure from the service manual as far as idling & the IAC are concerned.

I'm of the opinion that the throttle body is not to be taken apart so frequently. If it is getting dirty often, the problem lies in your air-filter or the PCV & EGR systems. While cleaning the TB might resolve the issue (temporarily), it appears to me that the root of the problem lies elsewhere...

P.S. - Referring to your engine bay pic above, a n00b question - is the brake booster on the F8D Alto on the passenger side ?

thanks a lot srini, you have helped me on number of occasions. do you have the soft copy of the service manual? please let me know the procedure.
yes the throttle body IAC bearing is very delicate and should not be opened so frequently. i too thought the air filter is the problem but i changed the filter too. i got a K&N replacement filter. how do i check the PVC and EGR systems?
even while coming from office i sprayed the carbuerttor spray in the valve and found black liquid oozing out. i am sure the carbon gets inside through the engine blowback gases.

its not my engine bay. i found one on the net. i too noticed that the booster is on opposite side.

Alto seems to be a wierd car been using since the past 2 days. Thought it was an abusive earlier driver thats why. But no, it just surprises me.

I think the K&N might be a step backward as I've seen it mentioned in many threads that these filters let more dust in than OEM ones.

ya i do agree to this. but i am using K&N since long time and even if it fouls the throttle body it wont foul @ every 500 kms. the recommended throttle body cleaning is 25k kms.

Sir, Can you elaborate on the above? Have you experienced the filter? And how is it related to amit's problem?

he is trying to say that that throttle body gets clogged due to excess dust that passes through the K&N filter. the frequent need of cleaning of throttle body is due to the k&n filter.
even if this is partly true i cannot believe that every 500 kms odd i need cleaning. i am using k&n since 2 years.

I got you there thanks. But the K&N is a better filter than the stock filter. It doesnt mean that one needs to clean the filter faster.

I've been using K&N for quite sometime now and have not faced much problems...but most of my vehicles dont have the fancy electronics!

Amit when was the last time you cleaned the K&N Filter ?

i got the K&N filter replaced. its a brand new with no traces of dirt. the old ones was used for 18k odd kms without cleaning.

i got my PCV valve checked. it was damn dirty and when opened dark black carbon flooded oil drops oozed out. the service centre didnt have a new valve so they replaced mines with one on an accident vehicle (alto). they have asked me to check for 2 days and report the performance. i will check consistently and update.

mine is a euro II complaint alto and does not carry and EGR system.

one more thing the MUL people told me is that if the IAC valve is clogged or if the functioning is not proper then we should face a jerk or the RPM should shoot up high. is this true? can someone throw a light on this.
in my case the RPM doesnt shoot up, nor i face any jerks.

Yes if there is a problem with the IAC then the idling rpm will shoot up.

after changing the PCV valve the idling has become better. also today i dint observe any fluctuations in the RPM on idling. i think the problem was with the PCV valve. yet i need to confirm as i dint drive much today. i hope this was the only problem and it gets sorted out.

Hi Amit, I'm glad you've got your idling issue licked :)

This got in the way :D Hence couldn't post from the service manual this weekend as promised !


Anyway, for the benefit of Alto lovers with idling issues, here is what I could find about the IAC & idling in the manual - the first image is of the PCV, where your car had an issue.


Now, for the basic checklist, pages 1...

... & 2.


The next bit is regarding the procedure to check something called IAC 'duty'. First is with the expensive Tech-2 I guess.

Next, is the procedure to check the same if a Tech-2 isn't readily available.


The throttle body, appears to be the same for both the F8D & the F10D engines.


The removal & cleaning procedure for the TB.


Finally, the IAC valve check - you have to look out for something that happens in 60 ms !?!


The service manual & parts catalogs are great if you're interested in knowing your car. Thankfully, the service manual for Maruti vehicles is no state secret (unlike a few other manufacturers), your regular dealer or service-center should be able to help you with getting a copy. For the Alto, the parts catalog is 300 INR & the service manual is around 800 INR.

thanks a lot SRINI, the manual is of great information. i am just wondering why do MUL A.S.S people dont follow the procedure from the service manual.
i remember when the first time i got my throttle body cleaned the first thing they opened was IAC valve, whereas it is written in the manual that the IAC should not be disassembled. they also cleaned it thoroughly with CARB cleaner spray. i hope it hasnt caused any problem to the IAC valve.

the procedure of checking the IAC functioning for 60 ms was also never done. they also told me that IAC cannot be purchased seperately. i have to purchase the whole throttle body.

now i have to observe my alto for idling issues for a day or 2 and confirm.
one thing i noticed when i removed my PCV valve was that there was rattling sound when i shaked it. in the manual its written that if it rattles its fine or else replaced.
i think i need to couple a TECH2 again and check the IAC duty.

yes!! the problem has vanished. no RPM dropping on idling, and no uneven vibrations.

Thanks to SRINI who directed me to the PCV valve. Also many thanks to other members who contributed their experience here.

PCV valve was the culprit here.clap: