Engine (equipped with Holley FI) sputters and dies when hot. Restarts after cooling-off.

I got my '72 Pantera back a couple of weeks ago after 4 years of renovation and some mods, and it was running rough so I took it back to the shop and with timing and fuel injection adjustment it is running great, or so I thought.  Two days in a row when the car was hot, it started sputtering and then died, and I couldn't restart it until it had cooled down for at least 30 minutes.  There was plenty of cranking power but seemingly no fuel getting to the engine.  Once cooled, it ran fine.  I didn't expect this when we switched to fuel injection, but in doing some reading since, it is not an unheard of problem.  Any brilliant ideas on the most efficient solution.  Obviously, we'll wrap fuel lines with heat resistant/insulating wrap and possibly a layer of a similar heat shielding material over the fuel tank cover, but are there any other ideas that will make me more confident that I'm not going to be left stranded in the middle of an intersection like I was two days in a row?

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Thanks, in advance, for any ideas or information.

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What brand and part number of fuel injection unit.  What fuel pump setup.  Post part numbers of stuff used.  I am running a FITech unit and don't have anything insulated and have never had a vapor lock problem.  I think something else is wrong.  Please give details and photos of installation and maybe we can help.

Norm

I have had similar problems in a few cars.   In a 67 Shelby 500 i could drive for about 15 minutes and it would stop running. As soon as it sat for awhile you could start up and drive but only for another 15 -20 min.   It ended up being crap in the fuel tank from gas going bad it would clog the filter from being shaken up when car sat it would drop back down so it would free up the pickup filter. 

The other car was my Pantera It had similar issue but it ended up being the coil it was getting hot and would shut the car off with no spark . Once cooled down would work fine.   

I have been using Holley fuel injection on a 351C for years and I noticed early on that starting when hot is a problem.It will crank fine but won't fire up.

Starts fine when cold. 

Believe it or not when it is hot it will flood after a couple of turns. I installed a simple on off switch that can be used to cut the power (positive) to the injectors (the ecu controls the negative).

I switch off the injectors while cranking the engine when hot to clear out the cylinders. After a few cranks  they will clear and the engine will fire briefly, then quickly switch the injectors back on before the engine dies.

Alternate problems are the stock fuel pump is rubbish and needs to be replaced. I use a Bosch 044 pump.

If you are using a stock In tank fuel filter (I'm not sure what Panteras have) I suggest replacing it with something built to handle a high volume (stock filters are only good for the mechanical pumps intermittent pumping action not the high constant flow of a high volume fuel injection pump). 

You need to check your actual fuel pressure or lack of. If you don't have at least a mechanical fuel pressure gauge somewhere on your system, you might consider installing one. I am not sure if your system has a hand held tuner or if you can have it attached to the system while the engine is running. If it is capable of having the lap top attached while running you can gather all the information that you need about what is going on with your engine.  You can also check all of the operational settings that relate to engine cooling temperature and ignition. 

I am using a port injected FAST XFI 2.05 system on my car and having all the information that there is available is certainly a blessing when it comes to trouble shooting an EFI system.

I have a Holley system that is about 8 years old. It uses GM style injector that sit above the throttle body in the air filter. I had one of the primary injectors start to fail and would be intermittent. This caused the car to lose power under acceleration. It took driving the car without the air filter and the passenger watching them spray to find it. This only after I checked everything else under the sun. If it had been a secondary I might not have ever found it. 

Steve 

Good point on the venting.  The gas caps that are sold today as vented really aren't like those of old.  They only vent one way.  For FI, it should vent both ways if there isn't a separate unrestricted vent line.   Thank all the emission controls vapor recovery systems for this fact.  I had to break out the check valve in my "vented" cap so it would vent both ways.  If you have what is called an anti rollover thing in the top of the tank, mine was just a piece of Heloise mesh which would vent both ways.  I made it into a return line plate so I needed a gas cap that actually vented both ways.

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