[drpullockaran]

Here is a bit of reading material for those interested.
Replacing the PCV valve

[amit_mechengg]

sorry guys, again the problem has popped in. again the rpm dropping and again coming to normal problem has started since yesterday. i dont understand why my IAC valve is getting fouled. while changing the PCV i had sprayed the CARB SPRAY into the IAC opening and flushed out all the dirt from inside. now again i think carbon/oil or something has fouled it.
now i will go mad if this problem is not sorted out. apart from PCV valve is there any other way that Idling becomes irradicate? is the role of PURGE valve/ Circuit coming into the picture?

[arpandiv]

Amit, I have a spare TB assembly including all sensors and IAC valve. Feel free to pick it up from Mumbai for testing purposes.However its of the alto 1.1.

I think you need to check the fuel pump also.

[amit_mechengg]

Originally Posted by arpandiv

Amit, I have a spare TB assembly including all sensors and IAC valve. Feel free to pick it up from Mumbai for testing purposes.However its of the alto 1.1.

I think you need to check the fuel pump also.

thanks a lot arpan, i think the one on alto, wagon r and alto 1.1 are the same. i have just returned from the service centre. we again overhauled the throttle body. did an exclusive test of all the parameters on TECH2.
TP sensor 0.8, throttle position 16-16.4 %, IAC flow perfect. all parameters are okay. the cleaned the IAC valve by coupling it to the sensor after dismantling it and switching the battery on and off. the actuator rotates smoothly. cleaned the IAC throughly with antirust spray and petrol. dried it with air jet. will check for 2 days now. the showroom people also said that they will swap another throttle body onto mines and check again if the problem persists.

by the way how did u get these spares? did u buy it or replaced it from your car?

[drpullockaran]

Originally Posted by amit_mechengg

sorry guys, again the problem has popped in. again the rpm dropping and again coming to normal problem has started since yesterday. i dont understand why my IAC valve is getting fouled. while changing the PCV i had sprayed the CARB SPRAY into the IAC opening and flushed out all the dirt from inside. now again i think carbon/oil or something has fouled it.
now i will go mad if this problem is not sorted out. apart from PCV valve is there any other way that Idling becomes irradicate? is the role of PURGE valve/ Circuit coming into the picture?

I seriously suggest you get a compresion test done of all the cylinders before proceeding any further. If the oil rings have kicked the bucket which will be after the compression rings you would have to do a rebore job.

[deetee]

I used to feel the same in my 800 too.Car was pulling effortlessly at times, under same conditions sometimes it used to drag heavily. Gradually the problem intensified and car started to die off suddenly while decelerating or idling.
This happened despite regular service at M.A.S.S center.
So, wanted take a chance with local garage(good one though) , it took 1/2 hour , the guy did something at the carb, pulled out a small nozzle like thing, cleaned it and replaced.Nothing else touched.
Car is running very smooth now, no rough idles,accelaration is smooth(i mean consistent).Best of all it is returning better fuel economy now.( Earlier,I used to rev it hard when it was not accelerating well)

[amit_mechengg]

Originally Posted by drpullockaran

I seriously suggest you get a compresion test done of all the cylinders before proceeding any further. If the oil rings have kicked the bucket which will be after the compression rings you would have to do a rebore job.

the compression has been checked its strong enough. its 10, 9.5, 10. i also suspected the same in first place. but everything seems to be perfect.

[drpullockaran]

Originally Posted by amit_mechengg

the compression has been checked its strong enough. its 10, 9.5, 10. i also suspected the same in first place. but everything seems to be perfect.

To do a jugaad way of testing compression leak is to open the oil filler cap and also remove the oil dip stick on a running engine. ( Be warned that oil will be splattered out of these orifices but rarely smoke in a petrol engine)

On a hot engine that is running if visible smoke seems to emmanate from either of the orifices then you should look up either compression leak from the rings or the valve sleeves. In a diesel engine you would see visible smoke but rarely from a healthy petrol engine. By the way this is how one confirms engine health when buying a second hand car as regards mechanical integrity.

There has to be a reason why your PCV and IAC valves are clogging up.

[badboyscad]

@ amit : i have posted some pics of the IAC valve in response to your PM regarding a hose connected to the IAC valve.i hope this helps.

The IAC valve(i guess) :


Bottom of IAC valve :

[amit_mechengg]

now i am really wondering how my alto has 2 outlets below the IAC valve. mine is EURO II model. if you refer to the 2nd picture, below the IAC valve there is not outlet pipe or any provision. it seems to be sealed. on my alto there is a outlet pipe which suggests that there should be some connection to it. but the connection is broken/missing on mine ( i suspect this ) as today i saw an alto in the garrage who has a pipe leading from somewhere to the IAC valve bottom.

[badboyscad]

Originally Posted by amit_mechengg

mine is EURO II model. if you refer to the 2nd picture, below the IAC valve there is not outlet pipe or any provision. it seems to be sealed.

Well, my bro's alto(to which the pics belong to) is a 2007 model. Anyways, i ll try to take a better pics showing the bottom of the IAC valve completely.

[vikram_d]

Speaking of hoses reminds me of vacuum. Check if there is any vacuum leak in the hoses that connect to the FPR.

Also ask the service guys about the hose that you have seen in other cars.

[amit_mechengg]

asked about the pipe to the service guys, they said that that used to be there in euro I altos which had coolant circuit, in EuroII there is just provision for connection but no hose pipes, and in EURO III there is no hole for pipe at all. will post the pics as soon as i get them

[amit_mechengg]

the problem has been solved. i had to change the IAC valve. spent 6 hours to find out the exact problem. then swapped the IAC from other car and it worked. so i changed the IAC valve. now there is no rpm dropping whatsoever.

i suggest you all that please dont open your throttle body for cleaning unless and untill really required. the IAC is very delicate part with a sealed bearing. once you spray the cleaner onto it, the bearing looses its lubrication and accuracy and all sorts of idling problem crop up.

[Jaggu]

Originally Posted by amit_mechengg

the problem has been solved. i had to change the IAC valve. spent 6 hours to find out the exact problem. then swapped the IAC from other car and it worked. so i changed the IAC valve. now there is no rpm dropping whatsoever.

i suggest you all that please dont open your throttle body for cleaning unless and untill really required. the IAC is very delicate part with a sealed bearing. once you spray the cleaner onto it, the bearing looses its lubrication and accuracy and all sorts of idling problem crop up.

Very good update, one more reason why one shouldnt run out and get the carb cleaning spray for a ECU car