fuel pump

[jackboeker83]

So I took the Roadster out for a cruise today with the wife and I am having fuel issues which caused the car to completely die and I had to get a tow home at 600 bucks. Ill explain my set up before I get into the symtoms.... MK IV 5.0 coyote with around 3k miles with external fuel pump (Vortech T-Rex 8F002-265 on summit).

As we were driving through the country hills of Texas the car would start to lose power for a split second then continue to drive for about 10-15 mins then it would happen again. I pulled over to check and see if maybe I had a leak under the hood or at one of my fuel lines and I didn't. At that point I figured it might be my tune acting up but it wasn't that big of a deal. Well about another 10-15 mins the car just shuts off in the middle of no mans land and I start to get worried. I once again open the hood and check everything again with no leaks present. I had my wife turn the key without starting it to check the fuel pressure and notice there is zero pressure at the fuel pressure gauge under the hood. I then check the fuel pump because I can easily see it under my exhaust and its barely making a noise. This fuel pump is actually pretty loud normally so I know something is wrong before the fuel pump or at the fuel pump. As I am tinkering with the fuel pump about 30 mins have passed and I am about to give up but I decide one more try before I call the wrecker... IT WORKS. Everything seems to be noramal and I didn't do anything to change it... we take off and try to make it to a town but about 5 miles down the road it shuts off again. As we drove those 5 miles I could feel the car wasn't getting enough fuel. This time I tried to give it about a 10-15 min break and hopefully it would start back up but this time it was dead. I called the wrecker and it took about 1 hour to get to my location. Once he showed up I said lets see if it will start and as soon as I turned the key it gave me no issues and started right up, then I drove it on the wrecker and once again when we got to our house started right up and drove into the garage.

My question is do you think its the fuel pump that only has 3k miles on it? This was an expensive fuel pump and when its working properly is pretty loud. When I was having these issues it didn't sound like everything was ok with it.... just a small hmmp instead of the loud sound. The fuel pump had made some extra loud noises very very briefly days/weeks before but didn't raise any alarms until of course today.

Any advice would be welcomed.

[edwardb]

Does sound like the pump failed. Agreed prematurely, but it happens. May or may not be anything you did. What size fuel lines (supply and return) do you have? I see this pump has 5/16-inch connections. That's sounds small for the flow it's rated at. Too small of lines can add drag to the pump. I installed 3/8-inch supply and return lines in my Coyote builds, based on multiple recommendations including Aeromotive. External fuel pumps, in addition to being noisy, also don't get the cooling effect of in-tank pumps. That could lead to premature failure as well.

[CDXXVII]

I am not familiar with the coyote fuel pump controls. Could it be a bad relay getting hot and failing.

[edwardb]

I am not familiar with the coyote fuel pump controls. Could it be a bad relay getting hot and failing.

Anything is possible. The fuel pump circuits in the Gen 1 and Gen 2 Coyotes are both rated for 40 amps.

[AC Bill]

An external pump would be loud'er, but if it's unusually loud, it sounds like it was failing.

As mentioned they can overheat, and work intermittently. Had that happen on a friends boat one time. Run great till the pump got hot, then dead in the water for 15-20 minutes..Once we figured it out, we would dip a rag in the ocean, and wrap it around the pump, to cool it down faster. We made it back to the dock thankfully.

$600 for a tow? Better join AAA or whatever auto club they have down in Texas.

[Rick1916]

I had problems with my Hilborn efi system on my 408 stroker that were traced back to a bad fuel pressure regulator if that’s worth anything.

[rich grsc]

Where is your fuel filter? There seems to be so many issues with external pumps.

[OVCobra]

As rich grsc asks, do you have a pre-filter between the pump and tank? If so, what is the filter rating (should be 100 micron or "coarse").
Pump could have failed due to a manufacturing flaw or could have swallowed a piece of dirt to jam the vanes or ran dry and seized.
Is the pump getting power (failed relay)?
I have ran external pumps for many years without issue but need to be set up right.
Check with Summit or Vortech,, got to believe they will replace it if failed prematurely.