#Vapor lock drivers
Should I run rubber line from drivers side front of engine to the carb? There seems to be two camps when it comes to what material to run for fuel line. Fuel line is spaced away from exhaust, intake manifold and does not touch engine anywhere. The steel line runs from the fuel pump up along the front of engine, infront of distributor across the front of intake manifold and back towards firewall along passenger side valve cover. The 3: of rubber line joins the steel line to the carb inlet. I run the stock mechanical fuel pump and ran all steel brake line from pump to 3" from carb. I could hear fuel trickling in the carb (Edelbrock.) I looked into the primaries and saw fuel just boiling away. The other day when it acted up I shut the truck off and opened the hood. I had fuel pressure after a few seconds so I reinstalled fuel line. I let the truck sit for 1/2 hour and pulled the fuel line off at the carb and had my father crank it over to check for gas flow. Today it completely died and there was no fuel in the carb. I've been breaking in the new motor (352) this week and have been having problems with the truck stumbling and dieing. Some believe steel should be used and some believe rubber as it expands and doesn't let the fuel boil.
![vapor lock vapor lock](https://i5.walmartimages.com/asr/636e62bb-a136-4fe4-a7c9-fc2b03890ec3_1.fed39f2f7d45501c4a227056d58f8d2b.jpeg)
Please, if there's any flaws in what I'm stating, correct me! That's the entire purpose of this post, I need education when it comes to vapor lock.I've been breaking in the new motor (352) this week and have been having problems with the truck stumbling and dieing. One question, can vapor lock occur when an engine is running? If so, what's the appropriate procedure to take? Run the aux fuel pump? I know it can occur before start-up, and I'm assuming that it then takes quite some time to restart the engine as the vaporized fuel is forced out of the line. Also, this can be caused by enough air being trapped in the fuel line either by improper venting or running a tank dry before switching. Thus, two things happen: one, the fuel pumps aren't designed to efficiently pump fuel vapors, and two, the pressure in the fuel lines as a result of the vapor attempting to occupy more space can cause the fuel not to flow through the injector and into the engine.
![vapor lock vapor lock](https://oazis.hu/app/uploads/2018/06/yucca-1.jpg)
In a fuel injected aircraft, a hot engine or nearby exhaust manifold can cause the liquid fuel being pumped through the fuel lines to vaporize, or as most people say, boil over. My understanding of vapor lock is the following: