Fuel line cooler?

[J-440]

I'm getting hot fuel back to the tank with less than 5 gallons in it and the car is dying. I've posted this issue awhile back and have gotten some great input from ya'll but the problem still persists. Even installed Aeromotive's fuel speed controller and while this is going to help, my car is still dying. Would an inline fuel cooler help?

[GoodysGotaCuda]

This is nothing unique to your car, every new car can run a tank down to nothing with no fuel heat issues and no dedicated coolers. The higher rail pressure of EFI helps ensure you do not have vapor locking issues.

How have you confirmed that the temperature of the fuel is the culprit?

[J-440]

Man I don't know what else to check. I'm getting a good 14.5 volts to the battery (that was a big fiasco awhile back). Everything is reading good on my laptop. Same thing that's been happening for awhile now. I start the car, warms up for about 5 minutes, I drive around the block for 3 miles and then the hesitation and sputtering starts. I can rev this thing to the moon and she sounds great during the warmup. Fuel pressure drops from 59 to 30 psi and eventually below 20 and the car dies. This is all with less than 5 gallons of gas. Won't do it with a full tank. Could it be the fuel pickup in the tank? I did have to custom fit it to my tank per Rick's instructions. Maybe I took off too much material and the pickup is sitting too high inside the tank?

[dhutton]

I think you answered your own question. It sounds like your fuel pickup is too short. That little bit of driving should not overheat the fuel in my opinion....

Add a gallon of fuel and see if it stops. If it does, I think that indicates fuel pickup is too short.

Don

[GoodysGotaCuda]

With 5 gallons of gas, if you unhook the fuel line and run the pump, how much do you get out of it? 5 gallons? 1 gallon?

Heat is very likely not the problem.

[J-440]

Good points. Gonna drain the tank and see how many gallons I have. If it’s what I put in, then I’m dropping the tank and see how the pickup looks. Any one of y’all have a forklift I can borrow? Rick’s tends to overbuild their tanks for reliability, quality....blah blah blah...they’re heavy as hell!!

[Mr Nick]

I'm not familiar with how a Rick's tank is built, but if you have any type of pick up tube, inspect it for pinhole leaks.

Ever prank your friend as a kid and poke a tiny hole in their straw and then watch them try to drink a soda?

[TheJDMan]

I'm currently chasing a very similar issue except that I'm having the dying issue even with a full tank. I was considering a fuel cooler as well but I suspect it would just be a crutch and not fix the root cause of the problem.

[CarlC]

Sufficient head pressure at the inlet of the pump is also a factor. A low inlet head pressure (low fuel level) combined with higher liquid temperatures and it doesn't take much for pump inlet cavitation to occur.

The modern fuel module keeps a 4"+ inlet head pressure available at almost all times. That helps keep the pump properly fed.

All it takes is a few times for the pump to run dry before it heads down the road to failure. I killed three pumps-on-a-stick in mine before figuring that there had to be a better way. One has to try pretty hard to kill a modern fuel module. About the only way is to run them dry or dump a load of nasty contamination in the tank.

[J-440]

Ok, I definitely have a fuel heat related issue. Filled the car with 10 gallons and drove it about 20 minutes and then the sputtering starts, then the car dies. I check my regulator and I'm getting 0 psi. The return line fitting to the regulator is hot to the touch. The sending line is only warm. I let the car sit for 10 minutes and she fires right up and the regulator reads 59psi. I wanna get a thermo gun and see what the temp is on that return line. I understand that these newer fuels boil at only 200 degrees? Man that's low. Would a cooler mounted to the radiator for the return line remedy this or am I just putting a band aid on a bigger problem?

[ULTM8Z]

is the fuel line running near something hot like the exhaust?

on my Miniram intake, I isolated the fuel thermally rails using composite bolts and washers.

https://www.thirdgen.org/forums/alte...ting-fuel.html

I think you guys probably have composite manifolds to begin with. but I do think high fuel temperature can cause issues based on what I found.

[J-440]

I’ve got the lines insulated just as they begin going beside the header collector and all the way up to the intake. My fuel rails are really hot as well. I read the post with the spacers, seems like that would help. I also found some fuel rail hi temp wrap that will lower the temp by 20 degrees. Only other thing is that my exterior mounted pump is about 8” higher than the tank. I heard for maximum efficiency you want these suckers lower or even with the tank. Preciate the help.

[dontlifttoshift]

Why do you have a fabricated tank and a exterior fuel pump?

[J-440]

Old school way of thinking. I had a 67 Coronet 440 with the exact setup except that it was carbeurated. EFI is a new animal to me and I made a lot of mistakes. Haven’t gotten a temp reading on the pump or the rails yet. I will this weekend though. Let’s say the pump is what’s making the fuel hot, then what? Find a lower mount for the pump so gravity can work better? Under 3500rpm the pump is only going at 25% but yet I’m still getting vapor lock. Still checking out the vaporworx website, great info.

[icemanrd19]

Had a fuel pressure issue with another car recently but the pressure would actually go up. Found out after driving it some the fuel hose kinked up close to the headers causing fuel to fight its way back to the return. Eventually the car would die bc the pressure was too high

[JohnUlaszek]

Ok, I definitely have a fuel heat related issue. Filled the car with 10 gallons and drove it about 20 minutes and then the sputtering starts, then the car dies. I check my regulator and I'm getting 0 psi. The return line fitting to the regulator is hot to the touch. The sending line is only warm. I let the car sit for 10 minutes and she fires right up and the regulator reads 59psi. I wanna get a thermo gun and see what the temp is on that return line. I understand that these newer fuels boil at only 200 degrees? Man that's low. Would a cooler mounted to the radiator for the return line remedy this or am I just putting a band aid on a bigger problem?

How is your tank vented? If its not breathing the pump will start to pull a vacuum and this would lower the atmospheric pressure allowing the fuel to boil at a lower temperature than normal resulting in pump cavitation. FWIW, depending on the blend of fuel it typically starts boiling around 140F. Return style fuel pump running wide open, lowered car with reduced airflow under it, tailpipes running alongside the fuel tank, etc. could also be the source of your problem.

[Motobrewmaster]

I work with pumps daily for my job. You might want to lower the pump also. You are making the pump work hard. As already said you want to minimize the net suction head. This is especially true for lower vapor point liquids...i.e. fuel. This could be combining with what John said and is causing cavitation. Cavitating pumps will cause you to lose pressure, heat the fuel more and actually can damage the pump. not good. This is exasperated as you try to increase the flow.

I would try lowering the pump, shortening the inlet line (increase in size if possible too), checking that your vent system is working properly. Oh and make sure your pump is matched well to your fuel needs. Too big a pump does'nt help if it is mostly using it's energy to recirculate your fuel back to the tank. Just this brewer/engineers thoughts.

[Motobrewmaster]

I just reread my post and need to correct my wording."As already said you want to minimize the net suction head". That should say you want to increase the Net Positive Suction Head. I kind of short cut that and it could be confusing without the correction.

[J-440]

Got a 1/2" hole below the fuel filler cap with a line going through the floor. I am running an aluminum motor plate which is close to the passenger header which both fuel lines are running on the opposite side. That's where all the heat is coming from. I made a heat shield on the header side and the temp dropped by 50*. This seems to help, although I haven't had the car past 4th gear as I am in the process of tuning the FAST efi setup. And that's a whole other story!!