Coyote slow start when it’s cold.

[Mike Garrett]

I have a new, generation 3 Coyote 5.0 in my FFR Cobra. It run perfect and a dyno tune really woke it up. My problem is after setting over night it take about 12 seconds of cranking before it will fire up. All the parts for the engine came from FFR including the control pack, fuel pump and fuel pressure regulator. The problem is that the fuel pressure bleeds off over time and until pressure comes up, while it cranks, it will not fire up. After the initial start it fires up immediately during that day.
Looking at the fuel pressure gauge durning cranking it’s obvious when the pressure comes up it will fire up. Turning the key to the run position the fuel pump will not run until the engine starts cranking. My tuner, that’s does lots of Coyote swaps and overall Coyote works says that’s a common problem with aftermarket fuel systems. Does anyone have a similar problem? Or a solution?

[michael everson]

I have been saying since my second GEN 3 coyote that something changed and the fuel system no longer primes. The last 3 have all been the same way. I have a 4th that I will be firing up this week. Will let you know if it primes. Maybe there is some kind of one way valve that could be put inline so the fuel doesn’t flow back to the tank.
Mike

[Rsnake]

Mike, I had the same issue with my last coyote in a roadster, I swapped out the fuel pressure regulator that ffr had sent out with a new unit from Summit, a tanks brand. It solved all my issues. The ffr supplied unit would bleed pressure off instantly once the engine was shut down, the tanks unit holds pressure for a long time. My new coupe has the gen 3 coyote as well and I went with the tanks regulator and it fires up instantly.

[Mike Garrett]

I have been saying since my second GEN 3 coyote that something changed and the fuel system no longer primes. The last 3 have all been the same way. I have a 4th that I will be firing up this week. Will let you know if it primes. Maybe there is some kind of one way valve that could be put inline so the fuel doesn’t flow back to the tank.
Mike

My tuner told me that someone must make a back flow preventer. Sounds like the new poster on this thread might have a solution.

[Mike Garrett]

Mike, I had the same issue with my last coyote in a roadster, I swapped out the fuel pressure regulator that ffr had sent out with a new unit from Summit, a tanks brand. It solved all my issues. The ffr supplied unit would bleed pressure off instantly once the engine was shut down, the tanks unit holds pressure for a long time. My new coupe has the gen 3 coyote as well and I went with the tanks regulator and it fires up instantly.

Thanks, I knew there had to be a solution! Tanks makes several different regulators, would you please giving me the model number of the one you used?

[Rsnake]

I will have to look for the information but it's just the standard 35-70 psi regulator if I recall. Works great.

[JohnK]

I wonder why Ford would eliminate the pump prime, and whether this is something Lund could add back in with a custom tune?

[BradCraig]

As Everson said, my gen3 was a PIA on first start and didn't want to prime. I went with the Aeromotive regulator and haven't had a start issue at all. Personally, every piece of fuel system FFR sent is still in boxes.

[Mike Garrett]

I wonder why Ford would eliminate the pump prime, and whether this is something Lund could add back in with a custom tune?

I emailed Ford Performance about this but they did not respond

[JohnK]

My experience with them is that they are not great on e-mail response but are very easy to get hold of on the phone and very helpful.

[RBachman]

This is why I added a fuel pressure gauge and pump power indicator light on my 347. They are great tools to facilitate a quick diagnosis and repair.

[mikeinatlanta]

I have a gen 3 in a pickup. Ran into an issue where a rodent chewed through a wire in the fuel system. The result was that the fuel rail would no longer hold pressure and symptom was about ten seconds crank time. Not sure exactly what this device is called, but it is electrical and needs some sort of signal to keep fuel rail pressure while sitting. I simply saw the two wires chewed through, spliced, and the problem went away. Sorry I don't know what it's called, but it is two wires and located on the passenger side on the motor's fuel system near the rail.

Bottom line is the motor does need to keep head pressure on the rail or you will get long cranks, even in an OE application. The head pressure in OE isn't being maintained by a tight pump, it some sort of valve near the rail.

[michael everson]

Just started a brand new coyote today. Took forever to start but finally did. Interesting this one primes the fuel pump every time I turn the key on.
Strange
Mike

[Ducky2009]

My fuel pressure bleeds off too, but if I turn the key on for a few seconds before cranking, pressure is up where it's supposed to be. FYI.... External pump GSL392BX from Summit, with regulator on the firewall (not in/at the tank).
Lately, I've noticed a slight hesitation to start at times. I've discovered if I press the gas pedal a little it starts immediately. Was wondering if too much gas/not enough air was present to get a quick start. Something for you to try.

[Mike Garrett]

As Everson said, my gen3 was a PIA on first start and didn't want to prime. I went with the Aeromotive regulator and haven't had a start issue at all. Personally, every piece of fuel system FFR sent is still in boxes.

I just replaced my regulator and the problem did not go away. Overnight its okay but after about 5 days it is slow to fire up.

[klawrence]

If you have a gen 3 and take the fuel rail to high pressure fuel pump line off, take note on how it was installed. It will go on both ways, just flows only one way. Ask me how I know ......

[Mike Garrett]

If you have a gen 3 and take the fuel rail to high pressure fuel pump line off, take note on how it was installed. It will go on both ways, just flows only one way. Ask me how I know ......

I did not take any of the fuel lines off.