Bronco dies when hot - fuel injector?

[UTbronco]

We did an motor swap to 5.0 with mustang computer, and had EFI installed. I believe the fuel pump is installed outside of the tank. When we drive it for more than just a few minutes the fuel pump quits working and the engine just dies. After it dies, it won't start back up until it's cooled off for a long time (i.e. overnight). It's worse in hot weather. We've also replaced the fuel pump after it burned totally up, but the new one does the same thing.

Would moving the fuel pump to inside the tank help, or anyone have other ideas we should consider?

 

[Timmy390]

What kind of pump?
Where is it mounted? (outside the tank but where)

Have you verified you have power to the pump once it shuts off?

I run an E2000 mounted just above the stock tank and have no issues. I feel it gets just as hot here in AR as anywhere.....

Tim

 

[needsmoarturbo]

Moving it to the tank would probably help, but I ran for a lung time with a e2000 pump mounted on the frame rail without issue unless trail climbing in extreme heat I did encounter vapor lock, but don't remember the exact configuration at the time.
Where is your pump mounted?
Which pump is it. I have found some pumps are just garbage compared to other of seemingly the same design. Other things to consider are fuel filters clogging, routing of fuel lines, and placement of pump. Most high pressure pumps are good at pushing not as good at pulling, so mounting near the tank is best.

 

[needsmoarturbo]

Another thing to check would be the tfi ignition module thing that is mounted to the distributor base. Those will crap out when hot.

 

[Timmy390]

Also what type of EFI? return or returnless?

You can check to see if the injectors are firing with a "noid light". Got my set at Harbor Freight.

Tim

 

[suckerpunched]

I am running an in tank pump and like that system better but I did an EFI conversion on my brothers CJ7 12 years ago and used a frame mounted pump. He has never had an issue.

Is there a fuel return hooked up from the fuel pressure regulator on the fuel rail back to the tank?

I would verify your fuel pressure when it is running and check it when it is not running too, although sounds like it will be zero at that point.

When you cycle the key off and on without cranking the starter, you should hear the fuel pump run for a couple seconds and stop? If it runs constantly or not at all would tell us something. if it does not run at all, can you hear the fuel pump relay click when cycling the key? if so you should verify the fuel pump is getting power through the relay.

 

[JLBachs]

Any chance you could have a plugged fuel strainer in the tank causing the pump to work as hard as it possibly can?

 

[SHX669]

I had similar issues with a couple of electric fuel pumps , quit pumping after getting hot and or burn up . It turned out to be a problem with the PO wiring .
I'd use a relay and run 12V wiring directly to the pump - if you haven't done that already.

 

[ScanmanSteven]

It’s probably the computer. There are some capacitors on the board that go bad and cause this issue. Contact EFIguy, he can fill you in on how to fix it. Try running a hot wire through a switch to the fuel pump, switch it on when you turn the key on and my guess is you have found your problem. I had a similar problem, took forever to figure it out.

 

[PaveBronco]

It’s probably the computer. There are some capacitors on the board that go bad and cause this issue. Contact EFIguy, he can fill you in on how to fix it. Try running a hot wire through a switch to the fuel pump, switch it on when you turn the key on and my guess is you have found your problem. I had a similar problem, took forever to figure it out.

He did a good UTube video on how to do it, I just followed it, easy...

 

[UTbronco]

What kind of pump?
Where is it mounted? (outside the tank but where)

Have you verified you have power to the pump once it shuts off?

I run an E2000 mounted just above the stock tank and have no issues. I feel it gets just as hot here in AR as anywhere.....

Tim

I believe it's a BC Bronco's fuel line kit. It's mounted in the back close to the tank.

Also using their accumulator.

 

[UTbronco]

Another thing to check would be the tfi ignition module thing that is mounted to the distributor base. Those will crap out when hot.

Thanks for the response and ideas. I'll take a look at your suggestions. BTW - I see you're in Syracuse, we're to too far away from you in Hooper.

 

[UTbronco]

I am running an in tank pump and like that system better but I did an EFI conversion on my brothers CJ7 12 years ago and used a frame mounted pump. He has never had an issue.

Is there a fuel return hooked up from the fuel pressure regulator on the fuel rail back to the tank?

I would verify your fuel pressure when it is running and check it when it is not running too, although sounds like it will be zero at that point.

When you cycle the key off and on without cranking the starter, you should hear the fuel pump run for a couple seconds and stop? If it runs constantly or not at all would tell us something. if it does not run at all, can you hear the fuel pump relay click when cycling the key? if so you should verify the fuel pump is getting power through the relay.

Yes, definitely hear the pump run for a few seconds then stop just prior to cranking the starter. I don't believe we have a fuel return going from the fuel pressure regulator so that's something we'll take a look at. Thanks for the response!

 

[UTbronco]

I had similar issues with a couple of electric fuel pumps , quit pumping after getting hot and or burn up . It turned out to be a problem with the PO wiring .
I'd use a relay and run 12V wiring directly to the pump - if you haven't done that already.

That's not a bad idea actually...

 

[UTbronco]

It’s probably the computer. There are some capacitors on the board that go bad and cause this issue. Contact EFIguy, he can fill you in on how to fix it. Try running a hot wire through a switch to the fuel pump, switch it on when you turn the key on and my guess is you have found your problem. I had a similar problem, took forever to figure it out.

Will do - thanks for the suggestion!

 

[UTbronco]

Any chance you could have a plugged fuel strainer in the tank causing the pump to work as hard as it possibly can?

Hmmm, maybe I guess. We'll check it out -- thanks for the idea.

 

[Skiddy]

Yes, definitely hear the pump run for a few seconds then stop just prior to cranking the starter. I don't believe we have a fuel return going from the fuel pressure regulator so that's something we'll take a look at. Thanks for the response!

yeah if you don't have a return it will burn up the pump

 

[BGBronco]

I have a crate motor and then went to EFI. I had this long running issue of the engine dying. It was never consistent and a real pain. Before I did the EFI, I swapped out the mechanical fuel pump, voltage regulator, and ignition coil trying to solve the problem. Same issue. I did the EFI conversion a few months ago. Same issue. It turned out to be a bad ignition control module. As soon as I started to unplug it, the connectors basically fell about. $25 part that should have been replaced a long time ago.

 

[Broncobowsher]

An EFI fuel pump without a return is a dead headed fuel pump. You are probably warming up on 90 PSI of fuel pressure. Warmed up the fuel pump is probably overheated from running overloaded.

Bad ignition typically shows up hot as well. Without an ignition signal the fuel pump won't run except for the initial prime.

So much sounds like it could be a problem. I wouldn't be surprised if you have multiple fixes to get things right.

 

[UTbronco]

I have a crate motor and then went to EFI. I had this long running issue of the engine dying. It was never consistent and a real pain. Before I did the EFI, I swapped out the mechanical fuel pump, voltage regulator, and ignition coil trying to solve the problem. Same issue. I did the EFI conversion a few months ago. Same issue. It turned out to be a bad ignition control module. As soon as I started to unplug it, the connectors basically fell about. $25 part that should have been replaced a long time ago.

Oh dang! Well shoot, I'll add this to the list to check too. I'm tired of not being able to drive in the summer for more than just a few mins at a time.