Hello,
The car is a Hyundai Accent LC, 2002, gasoline with gas injection.

For some time there has been a difficult ignition on a cold engine. Sometimes it takes 2-3 tries until the engine starts. When diagnosed in the only recorded errors are related to the immobilizer, due to an attempt to start with a key that does not have the necessary chip, but it has been months since then and I am sure that it has nothing to do with the case.

After ignition, the car works perfectly both on gasoline and gas, there is no change in the speed, it keeps its revs.
What has been replaced so far is as follows:
- The spark plugs
- The spark plug wires
- Idle control valve(it did not hold idle speed well)

My main suspicions are on the fuel pump as I have had a similar case on another car and it turned out to be this, but I still want to ask what you think.

 

Given the symptoms of difficult ignition on a cold engine and the components you’ve already replaced, the fuel pump could indeed be a suspect, especially if it's not providing consistent pressure or has a weak performance at startup. Since the car runs well once started and there are no issues with idle or performance, it suggests that once the engine is running, fuel delivery is likely adequate.
Other potential causes could be the fuel filter being clogged, which can restrict fuel flow, or issues with the fuel pressure regulator. Cold start problems might also be related to the coolant temperature sensor or the engine temperature sensor if they’re not providing accurate readings for the fuel system to adjust.
Since you’ve already replaced the spark plugs, wires, and idle control valve, focusing on the fuel system and sensors might be the next logical step. Checking the fuel pressure during startup could help confirm if the fuel pump is the issue.

 

Thank you for your comprehensive answer.
I guess we have to check the fuel pressure on start of the engine to be sure if the fuel pump is in needed condition.

 

Exactly. Checking the fuel pressure during startup will give you a clear idea of whether the fuel pump is working properly or if it might be the source of your cold start issues. This can help you pinpoint if it’s the pump that needs attention or if another component is causing the problem.

 

Thank you! Do you have any idea what the cranking pressure in psi that a normally functioning gas pump should give on this model?

 

For your car the typical fuel pressure should be around 35-45 psi when cranking or running

 

Thank you once again!

 

You're welcome! If you have any more questions or need further assistance, feel free to ask. Good luck with your diagnostics!