Ask Xulfiqar - An Automotive Encyclopedia

[nasirjavaid]

hmmmm... let me share some pics to help understand.

EDIT: Pics not uploading...will upload in morning

Atlast managed to upload the pics... Please see and advise...

Flow of fuel also looks fine, means fuel pump is working fine
The pipe of vacuum dash pot shown in 3rd last post seems bit cracky but is working fine as when i remove it and put finger in front of it I can feel good suction and engine stalls while putting back immediately stabilizes the engine.

[greyhound]

Bro i want to know where to find the engine number on 2C diesel engine. I hav an indus corolla wid 2c engine, but dont know where to locate its number......

[Xulfiqar]

@Xulfiqar
How do i check the resistance of this coil pack? Which pins should i connect with DMM probes?

There is a crack on this one if you look closely.....does this mean i have to change it?

leave resistance for the time being, the problem with such coils is that the switching transistor is inside the plastic moulding and cannot be tested, however the way I test these coils is to do an ampere test on them, this requires an oscilloscope, usually each coil peaks at about 9 amps draw

btw - the coil is bad if there is a crack, the spark will leak from there. I also see rust stains on it which makes me think the area above the coils was flooded by "sarviss teyshun"

whenever you install such coils it is highly recommended to apply a little silicone grease on the boots so it does not sieze to the plug and also prevents arcing if the boot is old and loose.

[haiderjaved]

leave resistance for the time being, the problem with such coils is that the switching transistor is inside the plastic moulding and cannot be tested, however the way I test these coils is to do an ampere test on them, this requires an oscilloscope, usually each coil peaks at about 9 amps draw

btw - the coil is bad if there is a crack, the spark will leak from there. I also see rust stains on it which makes me think the area above the coils was flooded by "sarviss teyshun"

whenever you install such coils it is highly recommended to apply a little silicone grease on the boots so it does not sieze to the plug and also prevents arcing if the boot is old and loose.

Well I have this doubt that atleast a one of such 4 coils/adapters are not working fine for my civic.
The same procedure to check them??
Does a road-side electrican figure it out with the procedure you mentioned?
I don't feel any missing, but facing a variation in fuel economy every time I top up my fuel tank.

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[DUDE007]

When the car is fully warmed up and at idle remove the connector on the coil pack one by one. If you notice no decrease in rpm on removing it then that coil pack is probably bad. To confirm this swap that coil with another cylinder's coil and see if it shows same behaviour. If so, then its bad.

[DUDE007]

leave resistance for the time being, the problem with such coils is that the switching transistor is inside the plastic moulding and cannot be tested, however the way I test these coils is to do an ampere test on them, this requires an oscilloscope, usually each coil peaks at about 9 amps draw

btw - the coil is bad if there is a crack, the spark will leak from there. I also see rust stains on it which makes me think the area above the coils was flooded by "sarviss teyshun"

whenever you install such coils it is highly recommended to apply a little silicone grease on the boots so it does not sieze to the plug and also prevents arcing if the boot is old and loose.

I don't have an oscilloscope at the moment. Is there any other way? Like the one i mentioned above?

Yes it was steam washed once. That would be the cause of rust.....

Is silicone grease applied only to the outer part?

[Driver41]

My mechanic suggested to replace brake discs/rotors of my khyber 99. I did some search and found that minimum thickness should be 8.0 mm (on this website http://www.acdelco.com.au/PDFs/Catalogue_ACDelco_Rotors.pdf )

Is it correct? Seems like my rotors are of 7.0mm. Shall I change them?

Any recommended brand?

There is corrosion on edge of one rotor from which there is squeal sound upon applying brakes.

[haiderjaved]

When the car is fully warmed up and at idle remove the connector on the coil pack one by one. If you notice no decrease in rpm on removing it then that coil pack is probably bad. To confirm this swap that coil with another cylinder's coil and see if it shows same behaviour. If so, then its bad.

I knew of this, but didn't know it is accurate enough to declare the coil bad. But still sounds logical...

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[nasirjavaid]

Atlast managed to upload the pics... Please see and advise...

Flow of fuel also looks fine, means fuel pump is working fine
The pipe of vacuum dash pot shown in 3rd last post seems bit cracky but is working fine as when i remove it and put finger in front of it I can feel good suction and engine stalls while putting back immediately stabilizes the engine.

Now this behaviour is totally random. Sometimes car seems just fine stable at 1000 rpm and after a drive of 10-20 minutes it again behaves strange on idle. And sometimes it fluctuates on cold startup and becomes fine after 10-15 minutes of ride.

I have to drive on motorway so am concious whether it will cause any trouble or not

@margallar @Xulfiqar anyone?

[DUDE007]

I knew of this, but didn't know it is accurate enough to declare the coil bad. But still sounds logical...

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You can try this test but you said you don't feel missing so it could be something else.

[Vaqas1]

@xulfiqar bhai i recently replaced my car radiator with a powerful fan. The thing i am observing whenever the autofan kicks in the radiator hose goes soft and thr is no more pressure in system. Thr r no leaks and fan is also auto with thermostat. Sometime before fan kicks in pressure is thr. Now whenever i park my car the hose are lose previously with weaker fan the pressure was always there. Radiator cap is also in fine condition denso one. I am facing no issues but still if this is how it should work.

[umarkhan1]

Xulfiqar bhai i recently replaced my car radiator with a powerful fan. The thing i am observing whenever the autofan kicks in the radiator hose goes soft and thr is no more pressure in system. Thr r no leaks and fan is also auto with thermostat. Sometime before fan kicks in pressure is thr. Now whenever i park my car the hose are lose previously with weaker fan the pressure was always there. Radiator cap is also in fine condition denso one. I am facing no issues but still if this is how it should work.

Which fan it is??

[umarkhan1]

Now this behaviour is totally random. Sometimes car seems just fine stable at 1000 rpm and after a drive of 10-20 minutes it again behaves strange on idle. And sometimes it fluctuates on cold startup and becomes fine after 10-15 minutes of ride.

I have to drive on motorway so am concious whether it will cause any trouble or not

@margallar @Xulfiqar anyone?

That is the auto choke.you cannot see the throttle plates unless the carb is opened.usually unstabe idle is due to high float level

[wasim625]

@xulfiqar bhai i recently replaced my car radiator with a powerful fan. The thing i am observing whenever the autofan kicks in the radiator hose goes soft and thr is no more pressure in system. Thr r no leaks and fan is also auto with thermostat. Sometime before fan kicks in pressure is thr. Now whenever i park my car the hose are lose previously with weaker fan the pressure was always there. Radiator cap is also in fine condition denso one. I am facing no issues but still if this is how it should work.

It happens.
Rad. Hose gets soft when rad. Cap (kind of a valve) Opens to release excess pressure in the reservoir/expansion tank.
In you case it means you rad. Cap is working.
Though pipes shouldn't be that soft as they are when engine is off.

[nasirjavaid]

That is the auto choke.you cannot see the throttle plates unless the carb is opened.usually unstabe idle is due to high float level

Thanks Umar, I also got it checked by a mechanic and he also told that carburetor needs service and tikki (butterfly :)) needs to be checked. But he said its not dangerous to drive it on long route if urgent and won't cause any issue.

[margallar]

@nasirjaved, see that hole at 8 o clock position on the carburetor throat, spray carb cleaner in that in small puffs, keep the race cable pulled to keep the car from stalling, do it a few times, also clean the mess.

it might just do the job

the choke plate on my car goes much higher, but it depends really on how you have adjusted it

btw there is too much oil on the carburetor, you should test the pcv

[umarkhan1]

Thanks Umar, I also got it checked by a mechanic and he also told that carburetor needs service and tikki (butterfly :)) needs to be checked. But he said its not dangerous to drive it on long route if urgent and won't cause any issue.

Start the on cng to check if its throttle plates or the float

[nasirjavaid]

Start the on cng to check if its throttle plates or the float

Please explain a bit.. means i have to remove air filter and then start and check if butterfly moves or not?

[umarkhan1]

Please explain a bit.. means i have to remove air filter and then start and check if butterfly moves or not?

Carb float has nothing to do when the car is running on cng fuel.if the idle is stable then its probably the float if its unstable then its definately the throttle plates.fyi your carb has two throttles.one moves with the cable and the other moves on high rpms with vacuum

[nasirjavaid]

Carb float has nothing to do when the car is running on cng fuel.if the idle is stable then its probably the float if its unstable then its definately the throttle plates.fyi your carb has two throttles.one moves with the cable and the other moves on high rpms with vacuum

Yes on CNG idle is perfectly smooth. Issue is only on petrol and that too is random. 4 times out of 10 this issue occurs. I am considering tuning of card may fix this.