I drive an hyundai Elantra 2010 and it has this sickening ignition fault. I have so suffred from this vehicle as its the only one that I have. It all started somtimin June, this car will work optimally befor I park and then a few minutes later the engine will refuse to start. It will roll so badly that you'll feel the engine shake but it will not just start, then after a few minutes (btw 10 and 60 mins), it will decide all by itself to start again. I've seen my mechanic, he used his scanner but it didn't pick any error code. He went as far as distorting the electrical system and then scanned again but still no error codes so he gave up.
I took it to an auto workshop in ibadan which I assumed was more reliable 'cos the technician is an Engr graduate with some international technical certification. He scanned and it returned no error codes, then he promised to use a diffrenet scanner and then told me my ECU is and that it'll cost about 1m to fix. This was a NO NO so I left him and took it to the official hyundai service center in lag. They scanned and gave no error codes too but of course they ruled out ECU and didn't give me any clue.
I was out of the country for about 3 weeks in August and when I came back, the vehicle behaved well for about 2 weeks, but now, the fault has escalated. It happenes virtually everytime I park as against the initial once ina week/2 weeks.
Right now, I'm so confused. The highest authority in the land can't query it for nothing and 1m is too big to gamble with. Anybody with any clue pls.

U'll get the help U need bro...buh lol,dierz no kind of Topic i wnt see n this section..
The other was "My has started again",now here again "My car is going nuts".
Wish cars would be sensitive and respond well after flogging it.

Hmm!

CKP? *scratch my head* Aside engine ECU, injection ECU or ignition calculator, these are one of EFI components that can mess the system up in that manner. It could be that the CKP (Crankshaft Position Sensor) is failing intermittently. Note that not all scanners will see intermittent faults stored in ECUs. Specific scanners for car brands can get you such hidden faults.

Relay? Trust me, a faulty relay, that supplies +ve to ECU can give you similar symptom. They can be very annoying sometimes when they start failing.

A faulty CTS can give various symptoms, not just excessive fueling. It can cause hard start too , since it will feeding engine ECU wrong values which will could make the ECU to close the injectors/stop them from spraying fuel for a while. Try this. Next time the car refuse to start, go to the CTS (Coolant Temperature Sensor), unplug the sensor connector and start the car. If the car starts, you have found the culprit. You will find the CTS around thermostat housing. Usually, a 2-wire connector sensor. For Peugeots, they use Bosch CTS, which most times have green connector.

A wrong connection of sensors: connecting sensor A harness to sensor B connector would give similar symptom as well. It will make the ECU to shut itself off after a while, if the signals its receiving confuses it.

Manual troubleshooting can resolve your issue better than scan tool, which have proved unhelpful in your case. Take your time, the culprit is somewhere waiting for you to come find it. Patience is all you need to do that. Worst case, the ECU, but that should be the last resort. But it has not gotten to that, i think

Thats the problem with some modern mechanics. Relying on scan tool doesn't help. When the scan tool fails to detect the culprit, they become helpless. Manual troubleshooting helps one to acquire knowledge about a particular system or car, more than what scan tool could offer. Scan tool is more of "Exam Made Easy" or "Expo".

I can't think of any other thing now. Maybe others may have other ideas or what could be the cause and save you from doing the above manual troubleshooting.
Good luck.

Ikenna.

Ive dealt with a similar issue on an 09 elantra.
In this case the problem was a combination of connected issues.
The fuel pressure regulator and a pressure valve on top of the fuel pump.
Just ensure you do not do more damage to the car by having numerous trial and error fixes.
Your problem is most likely along the fuel lines which may explain why you do not have codes.

from the rundown of your story I will suggest you call ARS to help you examine the car, I am of the opinion the problem you narrated could be caused by a censor in the vehicle. you can contact ARS at Omole phase 2, in lagos on 08063208131 for thorough examination. Good day

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Longe Omolaja: from the rundown of your story I will suggest you call ARS to help you examine the car, I am of the opinion the problem you narrated could be caused by a censor in the vehicle. you can contact ARS at Omole phase 2, in lagos on 08063208131 for thorough examination. Good day

Too much info here that may drive you nuts. I'm now wondering if my suggestion won't become and information overload.

Whatever you do, Don't ever let anyone take you down the ECU or brainbox lane or you could end up in more trouble.

I know a lot has been suggested on what your problem could be and possible solutions but from my experience you really need to have someone with the right experience to look at this car physically.

From the way it sounds, your camshaft or crankshaft position sensor may be the culprit. In local parlancel, its called the starting sensor and it tends to have the habit of failing when its hot and that's when it has gone bad.

The car will start and drive perfectly until you switch off and the moment you try to start when the engine is hot, nothing. You will then have to wait until the engine cools down a bit before it would start again.

I have experienced this before and it almost got me changing lots of unnecesary things before I zeroed it down. Another annoying thing is that it won't show up on the scan.

If you happen to be in abuja at anytime before the problem is solved, let me know.


Car-Doctor.