Weak start-up after sitting for ~1 hr

[17022]

Anyone having trouble with this? I posted in the mega thread and only a single person replied saying they've never seen it before. Hoping to get a few eyes on this.

Take a look at this video:

It's in the shop now for this (among other things related to the transmission that they are also not going to fix). Ford called me this evening and said it seems fine... that it is a non-issue. It is bizarrely strange, and I damn near shtt myself when it does this. It is also causing the computer to throw a blind spot monitor fault on the dash when this occurs.

Cold startups are strong.
Hot re-starts are strong.
This behavior happens 100% of the time after parking the truck for an hour and coming back to it. I call it a "warm start."

It sounds like a vapor lock issue to me... But I have no idea where to start in diagnosing this. Seems I will need to solve all of these problems for myself.

 

[GCATX]

No idea, I use my remote start while I am in the house.

If it runs fine I wouldn't worry about it, until it's a problem. May be a weak battery?

 

[17022]

No idea, I use my remote start while I am in the house.

If it runs fine I wouldn't worry about it, until it's a problem. May be a weak battery?

I cannot help but wonder if the choking half on / half off behavior is what burned up my fog lights, which were permanently switched on through an Aux. They were KC LEDs.

I don't think it's a weak battery. If the battery were bad, the cold starts would be even worse.

 

[Megabass]

Those lights should have low voltage protection, but I'm sure they didnt like it and I wouldn't rule it out

 

[GCATX]

I cannot help but wonder if the choking half on / half off behavior is what burned up my fog lights, which were permanently switched on through an Aux. They were KC LEDs.

I don't think it's a weak battery. If the battery were bad, the cold starts would be even worse.

The fuel mixture may be different when it's cold, open loop. When it's still hot, maybe things haven't settled to whatever state is triggering it, battery still freshly charged? I really have no clue, battery is easy to check though.

 

[17022]

The fuel mixture may be different when it's cold, open loop. When it's still hot, maybe things haven't settled to whatever state is triggering it, battery still freshly charged? I really have no clue, battery is easy to check though.

I dismissed the idea of it being the battery, thinking a cold start would be the most taxing on it (which it does fine)... not a warm restart.

You think a weak battery could really be the culprit?


Sent from my iPhone using Tapatalk

 

[1BAD454SS]

I'm betting its something with vapor recovery from fuel tank , valve fails and fumes build up in intake when off for an hour making a rich mixture , that's why it is fine hot start and cold start . Hot start fumes not building up yet, up cold start fumes are dissipated .

 

[17022]

I'm betting its something with vapor recovery from fuel tank , valve fails and fumes build up in intake when off for an hour making a rich mixture , that's why it is fine hot start and cold start . Hot start fumes not building up yet, up cold start fumes are dissipated .

That was exactly my thought as well. The canister purge valve?

I suggested that to the ford tech and he shot it down. (He said these engines are either port or direct injected, I rebutted "they are both," and he shot it down again for some reason or another.)

Ford called me later in the week saying "their computer isn't throwing any error codes, so as far as they can tell everything is fine."

FFS. If that purge valve is $30 I'd rather do it myself than take it back to them. That would be your best guess though?

They won't even try to diagnose an issue being present unless their stupid ****ing computer readout tells them there is something wrong.

Primary reason my truck is in the shop is related to the transmission and they're spewing out the exact same BS about no codes in "the very advanced" PCM/TCM modules. Truck bucks violently when shifting from park to drive. Enough to make me worry it will damage something in the drivetrain. Enough to lurch the truck forward if I'm not heavy on the brake. They reset the PCM the first time I brought it in for this which fixed it... I thought I shifted into neutral the first drive off... Which is closer to how it should be. Problem came back over the next month so I brought it back. Their solution was just to reset it again and tell me it's good to go.

 

[jabroni619]

That was exactly my thought as well. The canister purge valve?

I suggested that to the ford tech and he shot it down. (He said these engines are either port or direct injected, I rebutted "they are both," and he shot it down again for some reason or another.)

Ford called me later in the week saying "their computer isn't throwing any error codes, so as far as they can tell everything is fine."

FFS. If that purge valve is $30 I'd rather do it myself than take it back to them. That would be your best guess though?

They won't even try to diagnose an issue being present unless their stupid ****ing computer readout tells them there is something wrong.

Primary reason my truck is in the shop is related to the transmission and they're spewing out the exact same BS about no codes in "the very advanced" PCM/TCM modules. Truck bucks violently when shifting from park to drive. Enough to make me worry it will damage something in the drivetrain. Enough to lurch the truck forward if I'm not heavy on the brake. They reset the PCM the first time I brought it in for this which fixed it... I thought I shifted into neutral the first drive off... Which is closer to how it should be. Problem came back over the next month so I brought it back. Their solution was just to reset it again and tell me it's good to go.

It's hard to find good dealer techs. They remind me of tier 1 technical support representatives. If the issue you're having isn't a well known, documented issue with a step by step documented solution right in front of them, they tend to be pretty useless. There are some exceptions, but I've found this to be the case by in large.

 

[1BAD454SS]

May also be your fuel pump. Check valve that holds fuel in the lines . Not sure how the new trucks are but i can hear the pump prime as soon as the key is put in the ignition on my 14 . Hot start pressure and fuel is there , warm start pressure and fuel has bled down. Your ECM may not prime the pump . Cold start ecm primes pump. Just speculating here . I know if i shut my 14 EB and try to restart right away i will get a long start like in your video