How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ron Your Own Question
Ron, ASE Certified Technician
Category: Kia
Satisfied Customers: 35614
Experience:  35 years as an automotive tech
Type Your Kia Question Here...
Ron is online now
A new question is answered every 9 seconds

Kia Sportage: our kia sportage on a hot day runs fine

Customer Question

our kia sportage on a hot day runs fine for about 6 miles then begins to loose power. new plugs, new gas filter, it acts like is not getting enough fuel. it does not have a liquid vapor seperator like the picture does next to the fuel filler. have disconnected hoese to the charcoal cannister, and from the purge control solenoid valve, non seem to help. when turn the ignition off, it will run fine for about another 6 miles then the same problem.
Submitted: 2 years ago.
Category: Kia
Expert:  Ron replied 2 years ago.
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
The problem you are describing does sound like you are having a fuel pressure problem. The place to start is to connect a fuel pressure gauge to the fuel system and monitor the fuel pressure while the problem is occurring. Normal fuel pressure needs to be right at 42 PSI and hold steady. Anything less would indicate a failing fuel pump. Check this and post back with the results and we can work from there.
Customer: replied 2 years ago.
Hi Ron, I will try the fuel pressure test, but my confusion is that if the fuel pump was going bad, should the symptons be consistantly displayed? we only have this issues on hot days, over 90 degrees, and after the vehicle has been running for a while. On a hot day, we can run at 70 mph but eventually will start getting sluggish. When we get to a city and have to slow to or stop, the problem gets extremely bad. We have also identified that if we shut the car off entirely, then start is up again, we are good for about another 6 miles or so, then it has the same issue. The current code is a p0171 for lean air mixture. most of the fixes for this are vaccume leaks, mass air flow sensor, or fuel pump. but again, should the symptons be more consistant. If outside temperatures are in the 60 or 70 I can run all day long with no problems.
Expert:  Ron replied 2 years ago.
No , in most cases when the fuel pump begins to fail it will tend to over heat and when this happens the pump looses pressure. Checking the fuel pressure would be the first place to start to at least rule it out . The P0171 is a lean code and a failing fuel pump can cause it as well as the other things mentioned. Let get the pressure checked first while the problem is occurring.
Customer: replied 2 years ago.
With out the problem occurring the pressure is at 36 psi under idle and is AT 42 UNDER DRIVING CONDITIONS. NOT HOLDING STEADY BUT THAT COULD BE THE TESTING UNIT FLUCTUATION.
Expert:  Ron replied 2 years ago.
It should be right at 42 regardless providing your gauge is accurate , are you sure the fuel filter is clear?
Customer: replied 2 years ago.
I am testing line before it gets to the fuel filter. Put a new filter on 1 month ago
Expert:  Ron replied 2 years ago.
The pressure should still be right at***** Anything less would indicate a weak pump.
Customer: replied 2 years ago.
So ur initial recommendation is replace the fuel pump. Let's say I get that done and the problem still occurs. What would be the next step to diagnose the issue?
Expert:  Ron replied 2 years ago.
I would not replace it just yet, I would leave the gauge connected and recheck the pressure while the problem is occurring. If the pressure then still drops off there is nothing else that can cause this besides the fuel pump.
Customer: replied 2 years ago.
Under hard acceleration the pressure dropped to below 20 right as we hit the shift point on the transmission.
Expert:  Ron replied 2 years ago.
It should not drop at all under load and actually should go up about 5 PSI under load. There really is noting more then a failing fuel pump that will cause this providing your filter is clear .
Customer: replied 2 years ago.
Just put in a new fuel pump. Now there is no fuel pressure at all. Only 3 gal of gas in tank. Anything special to prime the pump?
Expert:  Ron replied 2 years ago.
The pump should not need any priming, go back and make sure you power and ground connection is good at the new pump.