here is the problem,on low rpm,car jerks,and jerks alot ,if i acclerate slowly.jerks wont happen,but if i try to accelerate a bit quicker,car will jerk and as it gets to higher rpm,around 2000,its all good again..car has no issue of mileage or any other problem . this jerk problem is on CNG but can also be felt on petrol.but on petrol its next to none existent. what ive tried to do to rectify the problem
1-new spark plugs, ngk japanese black ones.. nothin improved,wasted 750 for nothin,still have old set of wires with me
2- timing advance seems to have no affect on eliminating the problem,i installed STAP which puts on different timing levels for petrol on cng..ive tried all tuning for cng on my own,no avail
3-new air filter
4- mobil oil has been changed recently,approx 1500 kms before
any ideas?? could it be coil? but if it was coil,missing/jerking should have been there on high rpms too
please help me out,its makin me nuts...