Extended Crank, thoughts?

This has been happening for a while, after the truck has been sitting (overnight, work shift), and I don't start off with my foot on the gas, it will take a full crank cycle and a half, but if I barely put my foot on the gas pedal it starts right up every time. I preemptively ordered a new fuel pump because I've had fuel issues before, but if it were the fuel pump it would have problems starting whether my foot was on the gas pedal or not.

But if I've been driving for a little bit and it's at least a little warm, not full operating temp., it fires up no problem without my foot on the gas.

Dirty throttle body maybe?

'12 CM 5.7 FFV, 205k miles

 

The symptoms you cite are very indicative of the fuel pump. In particular the fuel pump's anti-backflow valve. It is allowing fuel to flow back into the tank after sitting an hour or more (common issue on many makes of vehicles). Once warmed up, then shut down for a brief period, it will start right up because it hasn't had the time to drain back yet.

I think you're on the right track...

 

We don't have a "Gas Peddle" anymore, it is an "Air Peddle", the ECU determines how much fuel to inject depending on the throttle body position. Could your throttle body be sticking?

 

Maybe you need a ECU SW update,

Look up cranking issues on FFV engines, very common issue with ethanol readings going array.

 

Possibly, I'm coming up on 210k miles, a friend of mine suggested cleaning the TB as well, I'll do that this weekend

I knew I shouldn't have gotten the FFV! I never use Flex Fuel anyway, since Sam's club/QT don't have it

 

CRC has a two in one kit. 2 cans. One for cleaning your MAF and the other for cleaning your TB. Maybe $10 tops. I use it. Good stuff.

 

I think you can get it at wallyworld, I'll check in later after I get it all done

 

When this happened to my 2007, it was the fuel pump and the immobilizer chip in the key.

 

Yep. Probably won't fix your problem but can't hurt. Preventative maintenance.

 

Well, it's definitely not the key because it starts, I had a '10 with 98k miles that the fuel pump harness actually burned up on the contacts on the pump plug, pump worked just fine if I jumped it, needed a whole new assembly. Dumb.

 

Mine would start, but the key chip was failing.

 

I agree with Johnsonman, if it is loosing its pressure in the line over time then it does sound like a fuel pump anti siphon valve that may be at fault. With the pedal pressed a little it is telling the fueling computer to add fuel, thus it starts, and once started then it probably works until it sits for that magic time (the pressure drops enough) then fails to start without pressing the pedal.

You might try BG products 44K fuel injection system cleaner. Good stuff works great, but is on the pricey side, (Napa Auto Parts) but well worth it if it is a dirty system. It will take a whole tank of fuel to clean the system. I would try that first before replacing the fuel pump. I have had very good results from 44K.

Besides the valve you may have a leaking hose in the tank that only effects a cold start with loss of pressure. Loose clamp etc. Because with that amount of cycle time until it starts sounds like loss of pressure and it takes that long to build up enough to start cold.

 

I'll give 44k a shot, I used 109 (pre EPR) and MOA in an old 280zx I had, I bought it after it had been sitting for four years. It ran like it was missing a cylinder, pulled injector pigtails and it wasn't firing on #5. Drained the old oil, filled with quaker state, 109, and an elephant fram filter, drove the crap out of it for about 30 minutes, and over that 30 minutes it got smoother and smoother, and eventually it gave me zero symptoms. Changed the oil, filled with proper oil and a Mobil 1 filter, business as usual.

 

You may want to look at the TSB. These FFV have issues with fuel pump and may require an ECU/ ECM reprogram.

 

According to the TSB, the bulletin doesn't apply if I'm not throwing a code

 

It states, May, in other words truck can possibly have a code. If you're experiencing symptoms then it will fall under this. Worst case scenario contact corporate, get a name and a point of contact to contest.

I took my truck in for frame inspection because it may have rust and may require treatment and or replacement. I got push back from the dealership, but nothing corporate can't override. I'm not being a dick about this, just trying to help you out.

 

Could it be that the pressure loss in fuel rails during work day/overnight is also due to a very slow leak in one of the fuel injectors? Helpful trouble shooting may be during start after overnight off-time, to turn the key to "on" then wait a 10-20 seconds before turning key to "start"; this allows time to fully re-pressurize the fuel rail. Slow leaks in either back flow valve or an injector would provide similar symptoms. Also the injector cleaner could fix the issue.

bjr