In chilly wet weather engine turns over but doesn't start.

[memphiskane]

That I'm not sure on 100%, I have yet to attempt to test my purge valve. Its either one of two ways for that one, put a vacuum pump on it and see if it holds or it needs to be energized then put a vacuum pump on it and see if it holds. I assumed my CCV was bad as the selenoid in it was clicking constantly so I just replaced it when i changed the fuel tank/EVAP air filter.

 

[wmcii]

Did you ever determine root cause? My 2012 4.6l is displaying the exact same symptoms. Car starts fine when cold start. If the car is warm and it take 3 or 4 tries to get the car started and idles at 1000 rpms (instead of 500). Power is also reduced. I don't have the tool to check the fuel pressure. My thought right now is fuel pump. Would love to know what ultimately resolved the problem for OP.

 

[PMCErnie]

Good old Chip Williams. We hardly knew ya.

 

[scottdk]

Did you ever determine root cause? My 2012 4.6l is displaying the exact same symptoms. Car starts fine when cold start. If the car is warm and it take 3 or 4 tries to get the car started and idles at 1000 rpms (instead of 500). Power is also reduced. I don't have the tool to check the fuel pressure. My thought right now is fuel pump. Would love to know what ultimately resolved the problem for OP.

This might be your fuel pressure regulator.

My neighbor has a motor home which has the GM 8.1L V8 and had the same issue you have. Started fine when cold, but when he would stop for fuel the engine had lots of trouble restarting, but eventually he would be able to restart and continue on his drive. He had an intermittent check engine light.

He asked me to look at it for him and I determined for his specific issue the most likely solution was to replace his fuel pressure regulator. There was no fuel pump issue since the vehicle ran fine, except for the hot start issue.

I replaced this fuel pressure regulator with one from Napa ($60) and the problem is completely gone, and this was about 3 months ago and he has driven quite a few miles on his motor home since I replaced the part.

- This is worth looking into for your issue in my opinion, but I'm not stating that changing your fuel pressure regulator will solve your problem.

 

[gselvo]

I have taken the car to three different good independent shops with NO firm diagnosis. Best guess is failing fuel pump or low fuel pressure from a clogged fuel filter. The fuel pressure test requires a special tool so my next stop is the dealer. My car has not thrown a single code... no engine lights even though after a hard start the engine idles high (1000rpm) and has little power. New data point. This problem is NOT related to the cold or wet even though that is when the problem first presented. The problem occurs when the ENGINE IS WARMED UP and the car has sat for a short time after a short trip. The car will turn over vigorously and not start. On the third or 4th try the car starts but has sometimes has a high idle and low power. If I drive the car in this mode for a while then turn it off it starts back up fine and runs normally (idle, 700 rpm and good power.) ? NO engine lights. I will run a can of seafoam thru the tank and will spray the throttle body. Thanks for that recommendation

I don't think any special connector is neded to read fuel pressure. My shop did it just fine. I have read that it cannot be read with OBD II - no readout provided by Hyundai.