Vapor Lock - Fuel Line insulation recommendations?

[timmycharger]

Been fighting vapor lock on my car for the last few years, just been too busy to correct it but now I have to address it after last week's episode when it almost left me stranded at a cruise night.  Looking for some suggestions on which products to get since what I looked into was very expensive for not a lot of coverage.

Right now I have a stock tank/sender that has a Holley HP 125/7PSi electric pump mounted on the rail in front of the passenger rear tire that feeds a 3/8 aluminum line up to a regulator which then feeds my six pack set up that has custom bent aluminum lines with -6 fittings.  I was not running a return line which I blocked off at the sender.

My plan is to install a return line back to the sender, I bought all of the materials already and just need to plumb it out, but what I want to do is cover the lines in a thermal sleeve and then wrap my electric pump in the same stuff, I think I saw one for a starter that may work, but since my pump is mounted very close to one of my mufflers, I need to do something.

I priced out the fuel line sleeves and they are crazy expensive for like 3 foot sections from Summit or Jegs.  Is there an off brand or something else that works just as well that wont break the bank?

[BLK 68 R/T]

I put this on mine where the fuel line comes close to the rear pipe.
https://www.mcmaster.com/standard-cable-sleeving

# 2627K31

[TexasStroker]

I feel your pain.  I know it is expensive, but I went with DEI.  I only run it in high heat areas and subsequently you won't need a ton of it.

If you just skimmed it, some of the really expensive stuff is probably the kind that has velcro (which is nice because you can easily remove it, reinstall it, etc.).  You can get the sticky versions for roughly 1/3" of the price.

I think I wound up with some Fire Sleeve and a stretch with the velcro, but this is more entry level priced and would be a good starting point:

https://designengineering.com/vapor-block-fuel-line-sleeve/

[c00nhunterjoe]

Your electric pump cant refill the bowls from a vapor lock situation?

[firefighter3931]

I've had good luck using the DEI cool tube conduit insulation on fuel lines and electrical wiring. Worked fine when I ran a mechanical pump.

https://www.summitracing.com/int/parts/dei-010415

I would run a return line to keep the fuel circulating. I would not cover the fuel pump with insulation as it will cause overheating and burn up the pump. The mufflers will not be excessively hot so the airflow against both the fuel pump and muffler case(s) is really needed to dissipate heat. 


Ron

[timmycharger]

Guys, thank you for all of the great suggestions and links, much appreciated! 

Your electric pump cant refill the bowls from a vapor lock situation?

Right after it stalled out, I assumed it just ran on what was left in the bowls since the fuel gauge on the regulator was at zero and the nozzles were just spitting out fuel.  After letting it sit about an hr, the pressure came back and it fired right back up.

[c00nhunterjoe]

Im not following how you had no fuel, but had fuel spraying out of the nozzles. I am missing something here. If fuel was spraying out of the nozzles, you have fuel going into the engine. The electric pump mounted by the tank should have no issue pushing any vapors through the line and out of the bowl vents in a boil situation.

[timmycharger]

I believe I said it was spitting fuel, I'm sure in your experience you know what nozzles look like when the bowls are just about empty.. not a steady stream, sort of just spits and it even sounds different.  not sure how else to describe it?   I would agree that  an electric pump should be able to push out vapors, but mine doesn't seem to. Its just a 7PSI internally regulated pump, nothing fancy.


Regardless, I'll be running the return line along with insulating the lines up to the carbs, should have done that from the start.

[c00nhunterjoe]

All im saying is that if you boiled the fuel out of the carb on a heat soak, 20 seconds of ignition run time on a 7 psi holley red pump should push through and refill. After that, crank and go. If you cant refill the bowls with a 20 second electric pump run, there is something else wrong.

[b5blue]

  6BBL calls for 5LB pressure yet at higher volume due to idle on all 3 bowls. Get a proper mech. pump and install return line/canister for stable as designed fuel delivery. Blocking intake heat crossover helps but adds a bit cold nature at first start.

[c00nhunterjoe]

No reason a 6 pack wont run properly on an electric pump at 7 psi. I have done many that way and all perform excellent.  While it seems our op has a fuel boiling issue. There is something else also going on that the electric pump is unable to refill the bowls.

[b5blue]

  Well off hand I can think of 5-6 reasons an electric pump could raise hell/create issues with a 6BBL. But then HOW the pump and hardware is installed can be issues. Also the pickup sock could be clogged, the bowls could be crusted with modern fuel crud and the rubber hardened sticking bowl float action. My reply was to encourage eliminating mumbo jumbo as pumps are not costly and vapor separators are what 75.00 now? The factory got it correct and the 20 odd years I ran my 6BBL daily and on 1,000 mile road trips proved it. About 15 years running in Florida's 90-100 degree heat with zero fuel boil issues using mechanical pumps.
( I'm not even debating how weak idle output from the ALT. could effect pump performance and that if that 15 foot wire to feed the 12V to the pump is too small or tapped into a crappy spot in the harness, or even the grounds to chassis, terminal ends, fuse size/placement/condition, pump age or the fact that it could be sucking air can come into effect. ) 

  So the car mostly sits not used? What kinda fuel you use? Hows the battery? Have you tested voltage at the pump? When is the last time you checked the fuel pickup?
 

[c00nhunterjoe]

Exactly! All of those points have nothingto do with the pump itself. Thats why i keep saying there is another underlying issue. Like you, i ran a mechanical pump and i had steel line, no return, for years without a vapor lock issue in 100 degree summer heat and using ethanol based fuels. I run electric now and still have 0 issues. None of my fuel lines are insulated.

[timmycharger]

Appreciate the feedback guys, the car was just finished about 2 years ago, replaced just about everything possible.  I am doubting there are issues with my battery, wiring, sending unit pickup or crusty bowls etc. I drive this car about 3 times a week, fires up immediately w/o issue every time and the only time I have had issues with this current set up is when the temp is above 90 Ambient.

Glad you both have had no problems in the heat, but every car/situation is different in my opinion.  My fuel line routing is not done like stock. I have a rubber line coming from the sending unit to the electric pump, then an aluminum -6 line running along the body then up on the front rail then straight up to the firewall where it goes up into a regulator. I think my issue is either around this area as it is pretty close to the headers, but it could also be near the intake itself as it is very close to touching it.   


I think at this point it wont hurt to wrap the lines near the carbs and where it goes near the headers.  I am also putting in the return line that I have sitting on the bench.

Not denying that I could have another issue at hand, but going to try this first since it is easy enough and I have most of the materials now.

Also, are you saying if I just let my elec pump run for 20 seconds it would have refilled the bowls? I had someone turn the key so I could watch the gauge on the firewall and I had zero fuel pressure for about 3 or 4 seconds. I had them turn it off because I thought that was bad for the pump to just let it go like that.  After an hour or so, just a few seconds with the pump going had the pressure back to 7 and it fired up right away.

Maybe I could have just left the pump running longer, who knows.

Here is a pic of how I have my fuel lines currently. They were very hot to the touch when the car was not running.

[green69rt]

As a test, you could get some welding mat and lay between the fuel line and the various parts of the car to see if anything fixes your problem.

Your comment about running the pump for some seconds and getting no pressure makes me think the pump is sucking vapor at first then when it cools off the vapor collapses and starts sucking liquid.  That makes me think your problem is in the suction of the pump.  Is there any way to lower the pump in relation to the bottom of the tank (probably not but thought I'd ask)?

Another test might be to get a can of gas and route a hose to the pump from the can.  See if holding the can at different levels (on a hot day) changes how the pump works.

[AKcharger]

I had vapor lock on both my chargers, tried everything, spacers, aluminum intake, fuel pump ect. In the end blocking off manifold heat riser and Cool carb heat shield completely fixed my issue. http://www.coolcarb.com/order-products.html

I didn't see one for a 6 pack but sure they could make one...good luck

[c00nhunterjoe]

Cool carb is good stuff. He is local to me. Nice set up.