CNG TUNING How to do it

[taim00r]

Hello,
I have got a 95 Civic with a standard engine , only modification is a muffler but even that was installed without altering the down pipeing.

I am having issues with the car's performance on CNG and Petrol!

i have got the car tunned and also changed the air filter and spark plugs( Denso 2 Tip)

The car still feels very Heavy and the pick up is very bad! the car is doing like 120KM on CNG in islamabad without AC!

I want to increase the performance of the car on CNG and Petrol! any suggestions?! and what would be the best workshop in islamabad to get the car tunned.

[iceman_kimi]

@crazy_rider
Removing oil from cylinder and kit will not do much to improve its pick and missing. You'll need to get your car tuned.

@taim00r
Get the timing of your engine checked.

[mostwanted_001]

What would you guys say about using 4pin spark plugs on cng? Or using any other plug for that matter except the common single pin one? Which one is better? Im running 4 pin plugs with a 50% blocked intake and those universal 11.9mm plug wires available from the market, its a 1800cc mitsubishi engine and seems to work pretty well. Would changing the plugs to a single pin one make it much better?

[bluespark]

please tell me the ideal avearge for khyebr on Cng.My car does 70 Km in 200 Rs in city w/o AC.i sometimes use heater.Is it ok?...

I ahve changed air filter,plugs were fine and have the rest of tuning form mechanic.he says its normal,but i think it should be around 100 km.Please help me in this regard.

Its 2000 model,stock engine in good condition.Thnx

[qwertypoiu]

what an excellent dig this topic would be...
this is a gold mine for CNG users...
well i would say is that the thing of blocking the air intake is still not fully explained

[ansar68pk]

@qwertypoiu

Ever tried pinching the tip of a garden hose to form a jet of water? The water spurts with greater speed and travels further than when the hose's tip is not pinched.

Well this thing seems to work in a similar way, only that the water is replaced with air and it is flowing into the hose instead of going out. Air velocity increases through the intake manifold and this increased air velocity seems to be a requirement with CNG and seems to give better volumetric efficiency with a different fuel !

This leaves me wondering about Turbo+CNG. I have a non-turbo car and would appreciate if anyone can share their experience with this.

[alikanju]

dear experts my car dnt start at petrol unless there is some cng...wat can be the problem?

[masudbd]

dear experts my car dnt start at petrol unless there is some cng...wat can be the problem?

1. Clean ur fuel injectors.

2. Go to ur CNG conversion center. Check how they setup fuel rail. they might disable the fuel path. tell them to fix it out.

3. Check ur Fuel pump.

[SpeedDemon]

I would suggest using hotter plugs on CNG. It has worked on a number of my friends' CNG cars, where we chose a hotter plug when using CNG.

For example, if you use NGK #6 plug, then shift to #5.

On ND, use #16 instead of #20.

Cheers.

[MarX]

i have 2007 GLi. Landi renzo kit with emmulator and advancer .last tune done on 12k by toyota capital . 60 kg cylinder ,its giving me 210 km on AC in city .andon motorway i got 250 kg .performance of a car is okay.low pick up in high gears but its okay as i normally have light foot on the pedal.milage now is 19.5 k ...

[hdaackda]

@request to mod: pls make this sticky? thnkx

now my question:

Problems with starting my Alto VXR (2005). I know, many have already asked this...

Car starts perfect on petrol and I park it in the night in petrol. On CNG, sometimes it starts in the first/second self, sometimes takes ages, sometimes it doesnt (have to convert to petrol)... I tried fiddling with the seconds and somehow I got a very good combo (worked fine) bu after a week, same problem..

Got it tuned from MANY people, but no one has been to solve it for more than a week. New oil, oil filter, air filter etc..Mileage is fine too...

any suggestions? or maybe i am doing something wrong in tuning?

thnkx

[Xplorer]

Is not it necessary to open up the CNG kit completely and clean its internals after about 5 years?

[ya123]

How much "Idle speed adjuster" screw should be tightened ? plz explain

[hammadameen]

gud info

[fnh]

Thanks all experts....and dummies..

Very informative attempts are made ....and one can learn amazing things from this discussion...But ....the discussion created alot more confunsion also....so it is requested please clarify your ideas completely....never assumed that all ppl know the all terms..
and if someone has little knowledge ..he shd make it complete first ..because ppl believes in written material...so plz clarify ur ideas completely .

[alee1]

ye lo g gas tuning guide by me
set your car to 25o0 or 3o0o rpm.either manually(by pressing accelarator) or by setting your cars idle speed till 25o0/3o0orpm.then start to turn gas regulator main valve either clockwise or anticlockwise.you will notice marked difference when your car is tuned.matbal their would be a point where your cars rpm will increase noticibly.E.G if your cars idle rpm is set to 3o0orpm their will be a point twisting the regulator valve when your rpm increases from 3o0o to 34o0 or maybe 38o0.at this moment consider your cars tuning is done.now redo your idle speed to 5o0rpm(normal recomended rpm) or 8o0rpm(recomemded for older cars as oil pump indication begains to glow at 5o0rpm and engine sounds like car is dieing)).
or if you controled your idle rpm by pressing acclerator then simply release it.
then turn again peak gas regulator valve 360 anticlockwise(means gas khool do by turning knob anticlockwise 1 complete cycle).at this setting your car is tuned for 3o0orpm.but its pick would not be go0d thats why its advised to increase gas flow.this is done because your car was tuned to give optimum performance at 3o0orpm.(because it is assumed that a normal car drives most of times at 25o0-4o0orpm.therefore it was tuned at 3o0orpm.if u drag your car then set your idle speed to 4o0o or 45o0rpm and perform same steps as told earlier.now set your cars idle speed using secondary knob found on your kit.their are two methods of setting idle speed1)right method.(recomended)over here to0 you will notice after twisting knob their would be a point where your car would attain maximun rpm.but dont go for that as its of no use.instead trying open the knob to allow maximun air flow by turning knob anticlockwise and leaving it on desired rpm when and where reached.also check by giving your car throttle that when your engine after reaching maximum rpm of thrust which you gave when returns the engine dosent takes stroke(yani jab engine ko race d0 t0 chk karo k engine wapis jab aye to saans to nahin laita).if it takes stroke then again twist air knob to correct this problem.2)not recomended method.you can also set your cars idle speed by turning air knob in clockwise direction.by doing so you can restrict your rpm by limiting the amount of air.which is not recomended as in this case your car will take extra long selfs to start on mornings and on cold weather.
by doing the tuning as told the owners will get maximum efficiency of engine and the best milage possible by their cars
i hope readers will find this informative and this will help them a lot.
regards

[Hafeezbutt]

My Honda switches from petrol to CNG at 4000 RPM. Is there any way to reduce it to around 2000RPM. As 4000 RPM in city is difficult on busy roads.

[hammadameen]

good info

[hdaackda]

My Honda switches from petrol to CNG at 4000 RPM. Is there any way to reduce it to around 2000RPM. As 4000 RPM in city is difficult on busy roads.

yes, but you'll have to go to ur CNG wala for that... he'll reset ur switch (enter some sequence.. ) and adjust the setting (all without opening the bonnet).. its electronic settings.. will hardly take 2 minutes

[alee1]

My Honda switches from petrol to CNG at 4000 RPM. Is there any way to reduce it to around 2000RPM. As 4000 RPM in city is difficult on busy roads.

lolz.on still car u can give it throttle til 4k rpm and it will convert without going at high speeds on busy roads.
besides u can g0t0 some cng mechanic.he will solve your problem in no time