Jet black, sooty, dry spark plug

Tags: #<Tag:0x00000009f08260>

omeryasin (omeryasin) 2012-12-01 08:07:07 +0500 #1

My Mehran is giving less than 10 Km/L and spark plug turns black quickly. what sud the problem be???

mwm749 (Mohsin Wazir Malik) 2012-12-01 10:57:14 +0500 #2

Is your car FF CNG.
How old is it, how many kms done.
When did you change the air filter.
Whats the spark plug model, when changed.

omeryasin (omeryasin) 2012-12-01 13:55:24 +0500 #3

Its not FF CNG
it is almost 4yrs old.
Air filter is new
spark plugs model is Denso W16Ex-U

jz (jz) 2012-12-01 16:13:52 +0500 #4

looks like ur car is running rich

omeryasin (omeryasin) 2012-12-01 23:47:57 +0500 #5

means???

Vaqas1 (Vaqas1) 2012-12-01 23:59:06 +0500 #6

Try to get the carb adjusted. Go to a good mechanic who knows how to adjust carb's as most of the mechanics forgot how to work on carburators due to CNG :p.

If nothing work only option will be to buy a brand new or used carb which is never repaired or adjusted and you will get around 15 kmpl.

Running rich means there is a ratio in which air and fuel is mixed for burnin when this ratio is not correct and more fuel is sent than air its called a rich mixture and if more air and less fuel than its a lean mixture. Both are not good.

omeryasin (omeryasin) 2012-12-02 00:13:46 +0500 #7

Any good mechanic in Rwp/ Ibd to whom I can go??????

jiggerzzzz (jiggerzzzz) 2012-12-02 01:41:29 +0500 #8

Well the Mehran is a problem itself :P.... there is an excellent tuner right infront of KHI company. I went there once with a friend dont know his name. but if you are going to KHI company via 9th Ave, taking a left after Pesh Moor and going straight through. You will have to take another left right infront of KHI company. His workshop is in one of the streets on the left opposite to the KHI Comp right at the end.
Sorry for the very vague directions but ill try and ask his name and address frm my friend and post it. Excellent tuner he is, and charges reasonable too

mwm749 (Mohsin Wazir Malik) 2012-12-02 05:26:59 +0500 #9

Dark coloring, such as heavy black wet or dry deposits can indicate an overly-rich condition, too cold a heat range spark plug, a possible vacuum leak, low compression, overly retarded timing or too large a plug gap.

If all the above are OK; then you need to try following.
Change spark plugs to NGK BPR-5EY or 5ES
Go to Suzuki 3S dealer and get the carburator Jets replaced.

mwm749 (Mohsin Wazir Malik) 2012-12-02 05:29:19 +0500 #10

Rich Mixtures: This condition is primarily caused by dirty air filters, If the fuel level is set too high in the float chamber, a rich mixture will result.

xenerking (xenerking) 2012-12-02 06:17:19 +0500 #11

mehran QABLI carburetor.....8k

better get it tuned....wont b that difficult...

omeryasin (omeryasin) 2012-12-02 17:09:36 +0500 #12

I think W16Ex-U is same as BP-5ES. both of these are recommended in Owner's Manual

omeryasin (omeryasin) 2012-12-09 03:06:23 +0500 #13

This is the result of plugs after one week i.e. around 350kms

Have it tuned earlier and after only one week.........

mwm749 (Mohsin Wazir Malik) 2013-01-01 04:20:34 +0500 #14

The plug on the left is OK, so its not rich mixture (Carburator).

-Check Valve clearance for all the cylinders. if OK then
-Get the cylinder pressure checked for all the 3 cylinder. if OK then
-Try new spark plug wires.

jz (jz) 2013-01-01 05:53:35 +0500 #15

check this pic for cross reference

argtr65 (argtr65) 2013-01-01 08:08:37 +0500 #16

It seems to me a weak ignition system,get it checked.