2001 Kia Sephia Has trouble starting when hot

JAMS62

MEMBER
2001 KIA SEPHIA
82,000 MILES

The Kia has trouble starting after it has been driven. At times it won't start at all until it is fully cooled down. I have taken it to a Kia Dealership and a Midas and still there is no fix. They are both at a loss as what the problem could be.

The following work has been done on the car:
- New battery
- Cleaned throttle assembly
- Changed spark plugs
- Changed fuel filter and fuel line

1 Reply

WRENCHTECH

MECHANIC
20,757 POSTS

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.