Suzuki khyber 1999 model missing on CNG

[shiekh123]

as salam o alaikum.

i am experiencing missing on my car suzuki khyber 1999 model running on CNG. on petrol is ok to drive. i experience this (jhatkay) while accelerating. the mechanic told me to replace the distributor cap. i did that and for some period car was ok. but now again started to do the same.

i would like to request @dani_kk mr. @Xulfiqar @MNabeel and other professionals to guide me.

thanks in advance.

[owais8668]

I also own khyber 1999.

And im also facing this issue.
In start there is some missing but after some time its not even drivable.

I changed distributor cap, Plugs, plug wires. And then car drive lag champ. But after exact 3 months or the next oil change. The issue came again.

I changed everything in december. Now the issue has started again.

[shiekh123]

@rajaatta @nnabeel @omersiddiqui5482 @dayrider @chall3ng3r @sayedarsalanali @imranmaskeen @agoodfriend @makhdoom007

PLEASE ANY ONE CAN GUIDE TO RESOLVE THE ABOVE PROBLEM

[sayedarsalanali]

This problem could be due to the timing of the car. In Carby cars, there is no advancer as installed with CNG kits in efi ones. So in case of carby cars, the setting is done on one fuel (either petrol or cng) the car's performance is compromised on the other fuel.

[sayedarsalanali]

You from Karachi? If yes I can guide you to a mechanic who can solve this issue for good

[shiekh123]

in my case yes, i cant feel such problem while driving on petrol.

[sayedarsalanali]

I had a 1992 model khyber, with cng and AC. The car was tuned on cng (as back in those days it used to be available all the time) , but when used to convert it to petrol it gave very bad fuel average + knocking.

[owais8668]

Peshawar bro

[sayedarsalanali]

I remember that there used to be a Chinese plug wires brand named Ultima, every other CNG carby car had to be fitted with those wires for good performance on CNG. Don't know if they are still available in market and mantain the same quality.

[sayedarsalanali]

What are your mechanic says in this drop in performance again? And btw what plugwires are you using?

[sayedarsalanali]

Found this image from my old pics of the "Orange" ultma plug wires, which were supposed to be installed in every cng driven vehicles

[owais8668]

He thinks that ignition coil is faulty, as it releases more current which is not required, result spark plug, wire damaged. (I also think so)
Havent changed the coil yet as im not getting the original one.

Im using NGK plugs, best quality available is market. Still have to changed them after 3-4 months.
Not all the plugs or wires are faulty at the time of missing. One or max 2.
But i chang all the related things.

I used sewa, NGK both brands for plug wires.

[dayrider]

So basically you are treating the symptoms instead of finding the illness and curing it

[owais8668]

If asking me.

Yes, you can say that.
Iwill not compare it to todays lockdown, because im not facing from few days, its an old issue.
Due to busy routine, i didnt find much time.
But after the lock down iwill sort out the issue.

Here is my khybers thread.

My Khyber 1999, Its Time to share the vehicle with Pakwheelers, Seeing is Believing

Honestly I was never a Khyber guy,.BUT the now adays traffic and the BRT (PESHAWAR METRO) Project was coming, so decided to have a vehicle for local use only. I bought this Khyber some time back, just to have in mind that it was only for local use. ALHAMDULILLAH I have more collection as well, But this was my first low budget and CNG car, we owned a CNG car back in 2008-09, then now. After looking at the traffic I plan to buy a low budget car just for local use,i have experience of buying…

[chall3ng3r]

i am experiencing missing on my car suzuki khyber 1999 model running on CNG. on petrol is ok to drive. i experience this (jhatkay) while accelerating. the mechanic told me to replace the distributor cap. i did that and for some period car was ok. but now again started to do the same.

To me it sounds like CNG supply issue. When you accelerate engine is not getting as much CNG as needed. I have no experience with carburetor engines, but I faced similar issue when I discovered fuel pressure was not optimal and my vehicle would behave same when accelerating.

[dani_kk]

Could be due to bad timing, more air flowing in on cng bad spark. It could be these two three things

[dayrider]

Your car needs tuning on cng, I had a khyber for 8 years, used on cng throughout, not once have I changed the plug wires or the distributor cap etc

[omersiddiqui5482]

Get the thing properly tuned on CNG. It is getting too much Air and lesser fuel... Hence the missing... Else I too drive a khyber and I have not even touched the distributor and wires in these 3 years on ownership... Just changed the plugs once...

[shiekh123]

i can feel some oil on the outer body of the cng kit. is it may be that kit needed a service? i did get it serviced from a true professional around 9 months ago. should i get it serviced again ??

[shiekh123]

how to get it properly timed? what should i tell mechanic about air flow? please guide