No Start without pressing gas

[Oxygen454]

I have a 2013 with the 3.6L. When I start the truck on cold days, I have to press the gas pedal. If I don't press the pedal, it will keep turning over but wont start. Once it starts, it runs fine. If I drive and shut it off and wait a few minutes, it starts right back up. If I start it a couple hours later, it stumbles a but and then fires right up. So it seems to have a no start condition after sitting for extended periods of time.

It did the same thing last winter and I just delt with it until the weather warmed up and the issue went away.

There is no DTC engine codes. I scanned the computer and everything looked normal before and after starting. I can't seem to find the fuel pressure anywhere on the scanner which is odd.

I was thinking fuel pump but they normally die off quite quickly. Tried searching the forum but nothing matches the same symptoms exactly.

One thing to note, when not pressing the pedal on no start, once I do finally press the pedal and it fires off, there is a fairly large vapor cloud of what smells like fuel. So I'm wondering if its cutting spark when I get a no start. (or lack of air, haven't looked at the air filter yet now that I think about it)

 

[Ken226]

Check the fuel pressure. If that's good

Remove and clean the throttle body thoroughly, then reinstall and do a throttle body relearn.

Or, reverse the order of the above.

If neither of those solve it, maybe clean the fuel injectors.

For each of the things I listed, there are videos available.

 

[Oxygen454]

I was leaning towards a throttle body clean and relearn. Will give it a go. There is plenty of fuel so I was thinking the injectors are good unless a couple are plugged.

 

[Ken226]

I was leaning towards a throttle body clean and relearn. Will give it a go. There is plenty of fuel so I was thinking the injectors are good unless a couple are plugged.

Injectors can be partially clogged such that all the low pulse width settings, not enough fuel gets through, but at higher settings it will run. But yea, it's less probable that the other possibilities

Also, with a weak fuel pump and low fuel pressure, the more common symptom is that it starts and idles good, but runs out at higher loads.




But, that depends on the mode of failure. The fuel pressure regulator is integral to the pump unit and low pressure due to a bad regulator can result in not enough fuel during cold, open loop startup, after which, the PCM can add fuel which masks the condition.

I think this is also less probable than the throttle body though, because it would probably set a code.

A good way to check is to use a scan tool to watch the fuel trim live data while driving. If the PCM is adding alot of fuel, it could mean clogged injectors and/or low fuel pressure.

 

[Oxygen454]

I got busy and forgot to reply here. I always like leaving the solution for others (and if the problem comes back)
I cleaned the throttle body really well. I also noticed with the ignition off, the throttle was open a good 1/4 (6mm) so I gently closed it. After the cleaning, the no start issue has not come back luckily. I didn't do a relearn but its been fine.

As for scanning, I didn't get a chance to check the fuel trims because its running well now but I'm still going to scan the trims anyway to see what they show. I noticed I do have two injectors that are very loud so they may be on their way out too. I thought it was the famous roller tick but to my happy surprise, its the injectors. Mechanic stethoscopes are great!

 

[Wild one]

I got busy and forgot to reply here. I always like leaving the solution for others (and if the problem comes back)
I cleaned the throttle body really well. I also noticed with the ignition off, the throttle was open a good 1/4 (6mm) so I gently closed it. After the cleaning, the no start issue has not come back luckily. I didn't do a relearn but its been fine.

As for scanning, I didn't get a chance to check the fuel trims because its running well now but I'm still going to scan the trims anyway to see what they show. I noticed I do have two injectors that are very loud so they may be on their way out too. I thought it was the famous roller tick but to my happy surprise, its the injectors. Mechanic stethoscopes are great!

Injector cleaning

Supposed to go cold and snow for the next 10 days,so i figured it was a good time to pull the injectors and give them a cleaning.Got them soaking in injector cleaner,where i'll probably leave them for a couple days before using some carb and choke cleaner to wash them out using my old homemade...

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