Ask Xulfiqar - An Automotive Encyclopedia

[Hassan1991]

Have you checked the wiring?

[pwuser155913790095]

u should check the wiring connection from a gud electrician with a multi metter most probably wiring is demaged

[aamirjimi]

hi sir, i have Daihatsu Hijet Cargo 2014 model Manual gear with 4WD option. during running when i slow the speed and need to change lower gear, my car's engine stop/shut down. please advise as soon as possible. (i have check engine oil level, coolant and air filter are ok)

[capsat]

you may please pay a visit to a workshop having automotive scanner. It seems there is either an electrical issue or a vacuum leak causing engine off.

[mwasimkhan66]

A.O.A sir i have a cultus efi 2007 model, car idles fine at 800 rpm but when i press accelerator car hesitates for 1 second and then accelerates fine no missing at all, and while driving it also do minor jerks from 1800 rpm to 2000 rpm below and above this specific range no problem at all. No trouble codes, LTFT is 8% and stft varies between 2 to 16%. Fuel pressure is at ignition on 40 psi and when engine is running the it drops to 28psi and stays there unless i remove the vacuum line it reaches to 40 psi kindly help me showed it to different mechanics but they aren't able to solve the problem,
Things i have done
Changed fuel pump
Changed spark plugs
Cleaned fuel injectors
Changed fuel filter

[capsat]

@mwasimkhan66 what else is issue beside 1 second delay? what about fuel consumption.
Fuel pressure is perfect, at ignition pump prime the injector rail once the engine is fired up pressure drop is perfectly normal. Vaccum line removal signal pretend engine dead ignition ON, therefore pump prime the fuel rail again.

[mwasimkhan66]

Thanks for reply, no such problem besides these two,
1hesitating while accelerating
2:jerks from 1800 to 2000 rpm while driving,
And above 130 kmph car feels heavy and takes alot of time to reach 140 kmph,
And about fuel average previously it was giving 14 in local with ac and 18-19 on long with, the average on long is same but in local it is now 12-13kmpl
I also replaced its clutch and pressure plates
Compresson of engine is 165 170 175 170

[dayrider]

Did you replace the fuel pump with a genuine suzuki fuel pump

[mwasimkhan66]

No it was of bosch company, btw problem solved it was actually the spark plugs they were gapped 1.2 mm adjusted the gaps to 0.7 mm and problem solved, car is smooth as butter now MashaAllah. BTW thanks for help

[brownrose78]

4 Finger gap--Theory which most of the suspension guys takes into consideration during fixation of car's suspension in Pakistan.

But nowadays, new JDM cars importing in Pakistan, their wheels specially rear ones do not have sufficient space like 4 fingers to go between Fender body and tyre.

Is this 4 finger gap exist in reality or just Ustaad Jee getting inspiration from 1 finger, 2 finger strategy of Gynaecologist

[xzap042]

Can you tell me what's up with number 2 spark plug? It seems like it is corroding

[tariqazama]

@Xulfiqar sir jee bari khamoshi hay

[capsat]

the plugs are they of same Part number of brand.

in the picture it seems TWO is over torqued and has more (reach) depth into combustion chamber then rest. fire burn cooked the base, Centre electrode appears more protruding then rest

@VCheng @dani_kk @rajaatta @margallar @nomi01 @hassan01 @SER_GTR @Babarhyd

[VCheng]

No.2 cylinder is burning a little bit of oil, nothing much.

[xzap042]

All are same BPR6EY I think. Torqued equally.

There is no oil reduction or burning issue. Even after 4000km oil level remains same. Car is carby Cultus.

To me it looked like it is corroding, previous plugs I took out were in same condition. This plug has chunks missing, I have no idea what is causing it.
I tried looking at piston heads with a flashlight, this one was black and other two were brown same like plugs. But I'm sure it's was not oil, seemed like carbon. Exhaust also doesn't have any trace of oil or greasiness. Engine runs fine.

[VCheng]

That little bit of carbon and blackness is the result of burning a small amount of oil. The engine is fine for now.

[xzap042]

Ok. But can you shed any light on why the plug is corroding?

[VCheng]

Clean it properly and then assess whether it is corroded or not.

[uzeemujeeb]

also perform compression test in 2 steps wet & dry.

[xzap042]

Yes I did clean it but didn't took after pictures, it's outer rim has chunks missing like it happens with rusted metal. Even tiny bits were coming off during cleaning.