Cultus RPM Drop when driving

[ali.arslan.netsol]

Hi all,

I have a 2007 EFI Cultus. It started giving this problem about a month ago and it just keeps getting worse. The problem is that when driving car jerks and RPM drops to zero then comes back up. Often car simply turns off and I have to start it again. Very rarely, car simply refuses to start for a min or so but then starts again easily after sometime. I have shown it to multiple mechanics yet no one has been able to solve it yet. Please see the video demonstrating the problem.

Video: https://drive.google.com/file/d/0B4QUg7a5OpK3bEFaWGR1aXgzRjA/view

What has been done so far.
One mechanic mentioned that the issue is with wiring. That its getting earthed which stalls the engine. However, he checked car with computer but couldn't find any problem. He also checked wiring but said that there was no problem in wiring too.

Another mechanic did the following (with a 5000 bill) to fix the problem but no improvement still

• Checked tappets
• Serviced throttle body
• Checked battery
• Checked wiring
• Checked spark plugs
• Changed some circuit related to distributor
• Checked fuel pipe

Air filter and oil was changed recently as well. Car was tuned couple months ago. I am really getting frustrated with this problem. Any help is much appreciated.

Thanks

[abid110]

Same happening with my Liana since 6 months. I have spent thousands and noone is able to diagnose this thing.

[gemini]

Same problem as mine. What i do is that I take it Suzuki Show Room and they do "laptop" i.e remove errors. Mine is CNG. I think this problem comes with 2007 model cars. I have changed a few things here and there and have adjusted myself to live with it until I sell this car.

[nadeemalib]

Same problem in my cultus 2009 i have changed spark plugs, clean throttle body, adjusted tappets, check wiring & tp sensors but no improvement. I just changed spark plug cable of ultima orange wire problem has been solved & improve pick also..

[dayrider]

2 things cause this issue, either not getting fuel, or not getting electricity.
since all electrics have been checked, check your fuel filter, fuel pump and fuel pressure

[ali.arslan.netsol]

Thanks for the suggestion, I got it checked last night and the mechanic couldn't find any problems. Whats the best way to check the electrics, I would like to go through them once myself as well.

[dayrider]

start with the spark plugs, check if all of them are working and getting current, the plug wires might be loose, check the battery if its generating proper current or not

[abid110]

As already mentioned above my Liana is having same issue but its only on AC. Otherwise it runs perfect and no rpm issues. With AC the rpm drops and car suddenly shuts down.

I have checked all sensors, they are totally fine, the TB is serviced and changed too, shim job done (as it has no tappets), coils are 100% OK, spark plugs are new, no spark plug wires in Liana, no distributor, but still it behaves same on AC.

What I conclude is that all mechanics from A tovZ are total useless. They are only good at changing/replacing parts and NOT in technical trouble shooting

[dayrider]

Your problem is rather simple, there is a breakage in current some place, when your ac turns on, it takes in excess current and results in lack of current to other devices and hence the power cut

[abid110]

What to do.plz suggest

[dayrider]

Check the current and voltage drawn by the air conditioner, it would probably be more than its supposed to do so, then check why that is happening, usually a wiring fault.
Secondly, check your battery, its condition and if its the correct size for the car or not

[anon29770314]

This post was flagged by the community and is temporarily hidden.

[anon29770314]

This post was flagged by the community and is temporarily hidden.

[ali.arslan.netsol]

WS. Its on petrol. No air filter busted so far. We messed around with wires a lot to see if we can locate the problem. Removed and reattached the distributor wire as well. The problem seems to have disappeared now however it always goes away for couple of weeks and then comes back so not sure if its fixed or just hidden. I had problem with my car where it wouldn't start at all about an year ago, which was resolved after changing the distributor. After 4-5 months of changing it, this problem appeared. So not sure if they are related.

Thanks for taking the time out to help.

[anon29770314]

This post was flagged by the community and is temporarily hidden.

[abid110]

Battery is new 65 rating cng Exide. Does Liana have any sensor which increases rpm for AC other than the iac? Its rpm drops when AC is turned on.

[ali.arslan.netsol]

aftermarket.

[miradnan786]

Dear Ali need not to worry doping RPM is simply the issue of fuel disturbance you have changed air filter and oil filter but most important in your case is fuel filter,
a) simply change fuel filter i hope your issue will be resolved and (if not resolved) go for option b
b) replace fuel pump
I had same problem in my cultus 2007 VXR; mechanics were unable to detect the issue and i logically back tracked the fuel supply and found the choked fuel filter, that i replaced and now my car is running perfectly.
Adnan Mir

[ali.arslan.netsol]

Thanks a lot for the suggestion Adnan. I will get my fuel filter checked out as well.

[dayrider]

Which again goes to show that its generating unnecessary load and in order for some form of compensation to that load, your car stops giving proper fuel to the car. Simply first check your fuel pressure, once with ac on and then with it off. hopefully it shall help you narrow things down