Missing when car is cold

[scorpion80]

u just need a tunining i guess .. !!!

[cracked]

i dont need tunning,my CAR does
yar its timing seals r leak n ive to get them sealed again..i need answer of 2nd question i asked in later posts...

[ahsanonline]

that behaviour on petrol when you switch it off is called dieseling (i think).

Have you checked/ replaced the petrol cut-off solenoid? it is the one that plugs into the carb itself, its got a wire or two going to it. Its supposed to stop this dieseling from happening...

[Xulfiqar]

when your engine is dieseling on shudown - check the positive side of the ignition coil that its not getting current from somewhere. If its not - then your engine is pre-igniting the mixture itself from excess heat. Check spark plugs - they are most probably too hot heat range for your engine.

[cracked]

ahsanonline
yup sir,ive checked tht solenoid,its on back of carb...i strted car on petrol,went to the carb n removed the electrical connection to tht solenoid,the car went off but even then,the car did DIESELING...tht solenoid is only to cut off petrol supply wen its shutoff so it is working properly i guess...

Xulifiqar bhai
spark plugs im using are NGK platinums coded BPR6EP...6 heat range is the company recommended, and also before platinums,i used DENSO W16EX-U..with denso too,the car used to do the same..
can u plz tell how to check the positive side of ignition coil???thing is ive changed coil to dry one,the one alto has..
cud it b like the mechanic said???k g timing bearing is one tooth advanced or something ???
car used to do dieseling for a long time but i mostly run car on cng so never bothered enough but now as gas is not available for 3 straight days,gonna have to do it corrected..
car runs fine on petrol with no smoke,but this stupid behavior on shuting off is really gettin on me nerves..anyone who solves,wins a BIGMAC

[Sultanfaseeh]

see if this could help https://www.pakwheels.com/forums/cng/172541-cng-cylinder-cleaning#post2935077

[ahsanonline]

BIGMAC????? yummy! im on it! lol

how advanced are your timings? are you using an advancer or just advancing right from distributor?

if you advance from distro then get one step colder (heat range) plugs, they may help with the pre-ignition.

ideally get an advancer, it should set things right.

when the car diesels at shut-off, try to put back timings to factory default on petrol and then see if it still has the same shut-off behavior - should rule out over-advanced timings as a cause.

and with that carbon in there, i'd recommend you to use liqui moly engine flush straight away. and try to use semi-synth oil. it doesnt (chemically) break down as easily and doesnt leave residues.

[cracked]

@ahsan..finally got the prob solved..
problem was butterfly was taking air,got it repaired,but problem stayed,then got half carb kabli n married it to the old one
there were some holes tht were out of specs due to which car was running rich..also float was out of its specs..set the float at 7mm from base as per repair menaual and now car is fine...no problem on petrol,black smoke is gone now as well as the dieseling thingy...
thankx for ur input..xulifiqar bhai has again proved to b helpful.

[SpoonMotorSports]

when your engine is dieseling on shudown - check the positive side of the ignition coil that its not getting current from somewhere. If its not - then your engine is pre-igniting the mixture itself from excess heat. Check spark plugs - they are most probably too hot heat range for your engine.

another possibility how abut some carbon deposits inside/across/wherever in the head are glowing hot and are igniting the mixture spontaneously ?

[Xulfiqar]

running on CNG does not create heavy carbon deposits.

[pwuser166835489671]

same problem hai meri Gli 2007 car main bhi mene sab kuch karwa ke dekh lia uska lekin masla hal nhe ho rha injector ,plugs ,throttlebody,coils,tappet clearance ,fuel pump change ,Almost every thing but ye cold start missing nhe ja rhi mene engine overhaul karwaya tha lekin valve ka kaam nhe karwaya tha isliye valve leak hain meri car ke i think ke last solution valve ki seats ko repair or valve repair karwani hogi mujhe