Cold start issues

[preston75052]

I have a 2007 5.7L Ram that runs and drives well! However, when It sits for a while it won't start unless I give it some gas. Once it warms up I can shut it off and start it back up immediately with no issues. I can warm it up to normal operating temperatures, let it sit for 15 mins or so and it will still be a little hesitant to start.

Any suggestions on what this might be? Any one having similar issues?

 

[Rlaf75]

It may be loosing fuel pressure after it sits for a bit causing the hard start. Run the engine until it's warm, shut it off and let it sit for awhile or until you think it won't start right up, turn the key to the run position but do not start it, you should hear the fuel pump run for a few seconds then stop. Once the pump stops, cycle the key one more time to prime the fuel lines and injector rails. Now try to start it. A fuel pressure gauge would be very helpful to determine the bleed off if that is the case.

 

[chefred112]

I agree^^ , mine does it from time to time...out of habit now I push the pedal to the floor and release and than start it....or, turn the key to on position and pause for a couple secs before i turn to start position...

 

[chris1965]

check the temperature sensor. when the sensor tells the PCM the vehicle is warm, when it's really cold, it just injects gas for warm start. that's not enough because the gas condenses on the cylinder walls and it will have a hard time to crank.

If there would be a leak, you would smell it.
if it's the fuel pressure valve, you would also have problems during normal driving. but still worth checking.

 

[preston75052]

check the temperature sensor. when the sensor tells the PCM the vehicle is warm, when it's really cold, it just injects gas for warm start. that's not enough because the gas condenses on the cylinder walls and it will have a hard time to crank.

If there would be a leak, you would smell it.
if it's the fuel pressure valve, you would also have problems during normal driving. but still worth checking.

That is true thanks for all the tips in advance!
Yeah the truck drives runs great and once it's warm, if I turn it off and back on no problems!

Someone was telling me it could be spark plugs are bad, or the coil pack. In this case, I did get a engine light, code P305 misfire, I got a firing diagram from OReilly and it's cylinder 5 which is right under the brake booster

 

[preston75052]

check the temperature sensor. when the sensor tells the PCM the vehicle is warm, when it's really cold, it just injects gas for warm start. that's not enough because the gas condenses on the cylinder walls and it will have a hard time to crank.

If there would be a leak, you would smell it.
if it's the fuel pressure valve, you would also have problems during normal driving. but still worth checking.

Where is the temperature sensor located on these 5.7L ?

 

[chefred112]

when was the last time you changed spark plugs? stickin with coppers right?