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Cold engine jerks


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roshain123
Novice

Feb 16, 2014, 9:29 PM

Post #1 of 15 (3483 views)
Cold engine jerks Sign In

Dear guys,

I am recently experiencing a problem with my car that it starts to jerk after 1 minute when starting the engine. This happens when the engine is cold and when started next time it works absolutely fine. Checked ECT, MAP, IAC, throttle body o/h, O2 sensors wiring, ignition coils, spark plugs, injectors and comprssion pressure. they all fine.


thnx for your help


Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 17, 2014, 12:03 AM

Post #2 of 15 (3464 views)
Re: Cold engine jerks Sign In

Maseratis all do that? Get the code #s and post them along with what this vehicle is and let's start there,


T



roshain123
Novice

Feb 17, 2014, 12:08 AM

Post #3 of 15 (3458 views)
Re: Cold engine jerks Sign In

Vehicle is a chinese brand named Geely GX2.
Mileage - 5000km


OBD codes - P0300, P03001 and P0300

this happenes during cold start up only. But when the engine turned off and started for the second time its fine. Damn jerking starts when engine cold.
No white smoke.


Thanksss!!!!!


Hammer Time
Ultimate Carjunky / Moderator
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Feb 17, 2014, 3:35 AM

Post #4 of 15 (3452 views)
Re: Cold engine jerks Sign In


Quote
Checked ECT, MAP, IAC, throttle body o/h, O2 sensors wiring, ignition coils, spark plugs, injectors and comprssion pressure. they all fine.


Exactly, how did you test all that?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 17, 2014, 4:02 AM

Post #5 of 15 (3449 views)
Re: Cold engine jerks Sign In


They do have such a critter. 5,000 KM = ~ 3,000 miles so let the guessing begin. It's new, what model year? Why isn't this under full warranty? Does it really even have OBDII? Country it was made for?


T



roshain123
Novice

Feb 17, 2014, 10:43 PM

Post #6 of 15 (3425 views)
Re: Cold engine jerks Sign In

Well i went to a service centre and got my vehicle checked. I was there standing and saw the guy checking all of them. he replaced everything mentioned previously with another same type car. But only thing left is the wiring. This is made for Middleeast. But at the moment we are in the winter about 20 degrees celsius. This only happens at the first start when rpm goes down at cold. Thats why the service guy also confused. He checked with the scanning tool but he is still struggling. this is 2012 model chinese. Now he is trying to check fuel side. Please help guys...!!!


Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 18, 2014, 2:29 AM

Post #7 of 15 (3418 views)
Re: Cold engine jerks Sign In

OK - Your technical help is marginal for you if I understand you. Fuel is burned as a vapor not a liquid and the colder it is and longer it sits in cooler or plain cold the more it needs to deliver the correct mixture ratio of fuel to air just till engine has enough heat of its own then all is good.


So the issue is likely that it can't sense what temp the engine is and make that adjustment so YES this would be a fuel delivery problem to focus on.


If wiring can't send the information it sees on to controls yet it still runs at all it's defaulting to work always as if it is warmed up.


You need the tech and test equipment with specific information on what should be what at assorted temps and bet the info/data and equipment is scarce just makes it harder to zoom in to the exact cause of this problem.


If places that sell this car do not have access to both the tools and data this will be a problem to find and fix. You need help and best if you can get this fixed before it warms up more for the seasons as the problem will still be there. 20C isn't considered extreme to an engine but still requires the fuel delivery right for a so called "cold" engine start.


This car is not sold where most techs at this site are from so can only help in the most basic ideas of how it should be working.


Good luck. You may need tech help from the car maker which should be available to the place that sells them new for a 2012 model vehicle,


T



roshain123
Novice

Feb 19, 2014, 5:26 AM

Post #8 of 15 (3401 views)
Re: Cold engine jerks Sign In

Dear Tom,

Thanks very much for your help. We replaced the fuel with shell v-power and waiting till tomorrow to do the check up. Will confirm soon.


Thanks

Best regards


Discretesignals
Ultimate Carjunky / Moderator
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Feb 19, 2014, 5:38 AM

Post #9 of 15 (3399 views)
Re: Cold engine jerks Sign In


Quote
he replaced everything mentioned previously with another same type car.


Interesting way to diagnose a problem. With it being so new, I wouldn't be surprised if they had some sort of reflash to correct that kind of problem.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


Tom Greenleaf
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Feb 19, 2014, 5:40 AM

Post #10 of 15 (3396 views)
Re: Cold engine jerks Sign In

Here - Shell V-Power is 93 Octane rated and claims to have more additives for keeping fuel items clean. In general more octane isn't necessary or helpful but not harmful. What additives IDK and doubt this is something dirty. No harm should come of it just not a fix.


Again and unique to the US mostly. I understand there are about 200 different formulations for fuel! Yikes! Which one does really do exactly what is a mystery to me. They do sell a "Winter Formula" that is supposed to be more volatile meaning will turn to vapor faster but I don't know what to believe?


The Summer formulas are being made now probably each is to reduce emissions for expected weather/temps but tend to think it's a crock of bull......... Tom



roshain123
Novice

Feb 22, 2014, 9:20 PM

Post #11 of 15 (3366 views)
Re: Cold engine jerks Sign In

Yes we replaced the fuel with super shell gasoline but same result. OMG this is very hard to solve. But never give up he he. Actually this must be a small issue which i am missing. Now again we are trying to replace the PCM with a new car.

What you think guys>


Regards,
Ros


Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 22, 2014, 10:30 PM

Post #12 of 15 (3364 views)
Re: Cold engine jerks Sign In

What I think: Unfortunately you seem to have a car and little info and equipment to deal with it. Swapping parts with one that doesn't have the problem if you and the mechanic is reduced to that may not work.


I can't know about this car at all just that the "PCM = Powertrain Control Module" may not just be a swappable part at all so I think you need proper info and the equipment for this. It just seems like that there's little to no support for this vehicle in it's location,


T



Discretesignals
Ultimate Carjunky / Moderator
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Feb 23, 2014, 10:56 AM

Post #13 of 15 (3355 views)
Re: Cold engine jerks Sign In


Quote
Now again we are trying to replace the PCM with a new car.



Why would you do that? There might be an updated software calibration that could solve your issue. You would probably need to have a dealer take a look to see if it has the latest calibration update. I don't know how they do it with the Chinese vehicles, but the factory may issue out technical service bulletins to their dealer level technicians to help them solve common problems or defects found after production. There could possibly be a bulletin concerning your issue.

Swapping another PCM might not work if the PCM has to be programmed for that particular vehicle. Even if it did work, the PCM you put in there might not have the latest calibration anyway.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Feb 23, 2014, 10:58 AM)


Sidom
Veteran / Moderator
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Feb 23, 2014, 1:29 PM

Post #14 of 15 (3346 views)
Re: Cold engine jerks Sign In

Hmmmm....Interesting thread.....I'll toss this out for the heck of it......

Just something to look at & very easy to check....

I've run into this complain a few times and once and while it wound up being a head gasket in the early stages of failure....With a car with this few of miles on it, I would be surprised if this was the problem but,,,,,head gaskets do fail sometimes on cars with low mileage...

The symptoms are pretty much the same as you describe......Runs rough on a cold start but then will run good on later starts.....The car needs to sit for long periods of time to run rough.....The clincher would be having to add small amounts of coolant to the reservoir over 2 to 3 week periods or longer.....

With this small amount of coolant going into the cyl/cyl's.....it's not enough to see any white smoke but just enough to make it run bad until it clears out.....

If the coolant level isn't going down at all.......Then more than likely the problem is some where else


Discretesignals
Ultimate Carjunky / Moderator
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Feb 23, 2014, 3:44 PM

Post #15 of 15 (3338 views)
Re: Cold engine jerks Sign In

That is a strong possibility Sid. Good to see you again : ) Pull the plugs and let it sit overnight with a coolant pressure tester on it. See if there is coolant laying down in the cylinders.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Feb 23, 2014, 3:45 PM)






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