Mysterious problem with mehran

[Ishtiaq778]

Salam,
I have mehran VX 2003
Problem: It jerks and almost lose power at speed of 80 to 90km on CNG. On petrol its quite normal and smoothly attain the speed of 110.
if i accelerate in 3rd gear, at 80km it starts taking jerks and in 4th gear at speed of 90 or 100.
Engine is good,New plug(Denso) New ignintion coil, New air cleaner,
Many times tuned by CNG technician but problem persists.
It embarassed me many times while overtaking, i have to quit overtaking with shame becase of these mysterious jerks.Plz suggest me what to do?

[dubai_autos]

Salam,
I have mehran VX 2003
Problem: It jerks and almost lose power at speed of 80 to 90km on CNG. On petrol its quite normal and smoothly attain the speed of 110.
if i accelerate in 3rd gear, at 80km it starts taking jerks and in 4th gear at speed of 90 or 100.
Engine is good,New plug(Denso) New ignintion coil, New air cleaner,
Many times tuned by CNG technician but problem persists.
It embarassed me many times while overtaking, i have to quit overtaking with shame becase of these mysterious jerks.Plz suggest me what to do?

It's nothing but bad CNG tuning..
Hit a good CNG tuner

[Ishtiaq778]

i got tuned many times from different CNG technicians. Every time they assure me but.............same result

[Hassan223]

Brother if u are facing any problem related to CNG or Mechanical trouble of ur car dn dnt hesitate for asking me for quality and satisfectory work . My cell no is 0321 - 4430780 .

[Asad_B]

mehran have many mysterious poblems

[fyq]

ishtiaq!
decrease plugs gaps jzt 0.02 mm as on petrol, advance ( ASSUMING factory settings in mid at 50%) to 60%, un block if any air is bloked, and thn adjust cng frm both the adjusters. it will be fine. (assuming u have new ORIGINAL plugs, injector inhaling of cng , gud point tip and new air filter (not GUARD))

[dr3vil]

tune it by a computerized CNG tunning place i used to have same problem

[Ishtiaq778]

Firstly i reduced Plug gap from 0.8mm to 0.6mm but car start missing and stalling. I thought, plug wires are faulty and i replaced with NGK plug wires set but problem persists.
At home i increased the plug gap upto 1mm 0.2mm more than standard. Now the problem is surprisingly solved. No missing or jerking.
0.8mm plug gap was creating jerks on CNG but 1mm gap resolved my problem.
im surprised.................

[ahm13]

its perfectly ok for mehran if its doing 80 90 km/hr on cng...

that engine produces 37 hp on petrol, on cng barely produces may be 31 32 hp, what do u expect from that kind of power,

on highway if u give mehran a long run on Cng with the wind then it might cross 110 thats really it. dont worry ur car is absolutely fine..

[tilsim]

my mehran did 130 on cng easy! (easy in comparison with other mehran's) yaar its no biggie, get your car tuned up from some good cng mechanic it'll be fine! plus as a test, try not to floor the paddle, accelerate it slowly slowly.. with a very light foot on the padle and see it does..

[rhaq]

Dear i was facing the same problem. The fault was in cng gauge switch installed on dash board. It was not passing the current to cng kit. Also i replaced venture with gas injector to direct inject cng to carbourater. Now my mehran is unbelievable pl try by urself. :s

[pwuser147934639689]

I know solution but cant explain it here u can call me bro my # 03457262914