Honda City IDSI Missing When Hot

[pwuser158814663739]

Hi All,

Please some one help me as i am fed-up from these Jugarhu mechanics,

i have Honda city 2005 idsi with 1.5 L swapped engine,

Car was working very fine few days earlier.

Now i am facing engine missing when AC on, Without AC its fine, Interesting thing is that missing start in afternoon, In morning its absolutely fine,

Mechanic had changed Fuel Pump with filter , Ignition Coils , Service Throttle body , TB sensor clean/adjust, All other sensors verification, Wiring check, Spark Plugs was also changed, Crank sensor was also changed

Engine is not consuming oil also not reducing water etc and have excellent fuel average

Experts please help me and suggests some solution.

@Xulfiqar and other experts

[nomi01]

Missing when hot is a sign of ignition coil problem, wud disappear when coil is cold

[pwuser158814663739]

Dear Coils were already replaced, bought Kabli from bilal ganj, But issue was same with new coils as with old ones

[Xulfiqar]

bought Kabli from bilal ganj

this means you dont have new coils - new means brand new from Honda. Scrapped parts are still scrap, whether you call them Kabuli, Qandahaari, Jalalabadi.

Misfire when hot can be a lot of issues, but mostly its due to ignition coils, spark plugs and also valve clearance (tappet setting) on your old Honda engine.

[hamza_iqbal]

If you think your coils are 100% fine then make sure you are using Iridium tip spark plugs. Yes, all 8 of them.

If you wanna make sure your coils are working, i-dsi has got two per cylinder, so starting from Cylinder #1, disconnect Coil #1 of Cylinder #1 and check if it's starts vibrating/ missing (which would mean the cylinder isn't firing), if it does then the other coil that is still connected (Coil #2) to Cylinder #1 is bad. If this isn't the case then disconnect Coil #2 and check if Coil #1 is bad. Repeat this for all the cylinders.

This will help you find out which coils aren't working but it won't help you diagnose which coils aren't giving the complete output i.e not performing at 100% efficiency.

Fuel pump could cause this too, after market ones usually don't do a good job when hot. I had a Honda Civic 2005 that had a bad fuel pump and caused missing while driving.

And valve clearances, make sure your intake is 0.16-0.19 mm and 0.26-0.32 mm exhaust. It has got 4 intake and 4 exhaust, 2 valves per cylinder.

That's all I know. Hope it helps.

[margallar]

Does city come with iridium plugs from factory?

Do copper plugs cause misfire?

[pwuser158814663739]

Thank you so much for reply sir,

Condition is same with new coils as well as old coils, So may be no issue with coils, Without AC every thing is as expected and no missing, Issue is when AC is getting on,

can this be due to wiring issue ? because with AC engine is getting too much load, i have changed the compressor 2 months ago.

Which nodes should i check for any possible fault?

[pwuser158814663739]

@hamza_iqbal, Thank you for your reply,

By starting from front side coils, When i removed Coils grip from cylinder 1 to 4 then there is no major vibration,

But from backside coils, When i remove 1st coil then engine vibrate significantly.

Isn't is possible for plugs to faulty instead of coils

[pwuser158814663739]

@margallar, i think copper plugs have low running life

[Xulfiqar]

looks like your car is a classic jugaaroo car of Pakistan, slap an engine, slap a compressor, shine up the throttle and and let it roll,

misfire under load when heated up is usually due to a bad ignition system, which also include spark plugs (a cracked plug will short out) - or an ignition coil tower which is leaking can short to ground.

This is not a hit or miss - get your car to a professional who knows how to test the secondary voltages of the ignition system (not teshtlempp ustaad)

Are you defnitely sure your engine is mechanically in good tune? including tappet setting? or are you just repeating whatever your mechanic told you.

and if your mechanic suggested new coils - go back to him and get him to pay for them if the "kabuli, qandahaari, jalalabadi" coils didnt work. Why are you paying for his trial and error?

[pwuser158814663739]

Actually i am still unable to found a good mechanic in lahore, Could you suggest me ?

Engine was tuned 2 times but tappet was not adjusted both time

Actually i had already paid more rupees than total engine price for these ustads trials

[pwuser158814663739]

Fuel average of car is good, Is it proof of good combustion / Engine / Spark Electrical System? , (As told by Ustads)

[margallar]

I had a car with plug wires so bad, that it could not maintain a fixed idle speed, yet fuel average was 16 km/l

so fuel average is not a guarantee of a good ignition system. Get some good quality chinese coils. install them yourself and then see how it goes.

Mian autos at Shadiwal Chowk should have them

[hamza_iqbal]

Check your coils and plugs again. I clearly remember when I owned this motor, removing backside coils didn't make the engine vibrate significantly. It idles the same when you remove coil from either side. Check the wiring too.

Hey. You know with A/C I had the issue of unstable RPM when shifted from D -> N or N -> D. Tuning the TP sensor, replacing the IACV helped a lot, like fixed it 70% of the times but the main reason for this was bad compression. My car was just 110K driven, periodic oil changes and everything but my experience with i-dsi was very bad. It was a CVT which comes without a torque converter configuration and it was surely the most sluggish car I had ever driven. I don't even remember driving it with RPMs in the 2K-3K range, always 3K+. I did had after market wheels but 1.3 liter 8 valve motor for a family sedan (where in Pakistan a family sedan means the whole family can fit in, 4 people, 6 people, a dozen people + luggage :P)

[pwuser158814663739]

@margallar , Do you have any idea of cost of these chinese coil ?

[pwuser158814663739]

Hi all,

Issue was resolved, By just adding a ground wire (upside of gear) with engine that i accidentally removed during horn installation

[nomi01]

LOL, slow clap

[Xulfiqar]

with engine that i accidentally removed during horn installation

go buy some lottery tickets or play some roulette - because your ECU didnt fry with a bad ground.

[pwuser161327577460]

i am facing engine missing when AC on, Without AC its fine,

I'm facing the same problem with my car city 2005 idsi 1.3 automatic. It starts missing when the AC is switched on and sometimes without AC to. Changed coils, plugs, crank sensor, fuel filter but still its missing. All mechanics are jugaru, please tell me from where and how to fix this. Thanks!