Anyone had a problem with nylon back braided hose sucking shut with MFI. I am not sure this is the issue but with the weak spot my main fuel line has on the suction side, it is highly possible or so it looks.

On the fuel lines I will not use anything other than the PTFE lined hose. It lasts much longer and does not degrade, crack and dry out like regular hose does. Really not that much more money and lasts WAY longer. Only draw back to it is you can not bend it much with out it kinking. Which you should have all the lines ran properly any way.

no but I do use there spring inside the hose to make me feel better

If I had a fuel line collapsing, the 1st thing I would look at is the fuel tank vent, especially if I was running methanol.

Joe

Like stated .Do not know but suspect ir could because it wseems very easy to collpase using thumb and finger squeezing it. Then it was middle finger anf it is strong from years of use driving highways every day.LOL

Think I am going to go back to the 12 line and install the spring as suggested If nothing else it will eliminate possibility of if happening.

Also a lot of dragsters use aluminum tube for much of the fuel line and then short rubber hose couplings.

quote:

Originally posted by Curly1:
Also a lot of dragsters use aluminum tube for much of the fuel line and then short rubber hose couplings.

Mine is aluminum from tank back to 1' before pump with short line and 458 up to pump to keep line out ofm kink and avoid a 90.

All of my older cars has alluminum all the way to pump with very short hose.like 3 inches and most of that was over pipe. It was also 1.5 to 2" line depending on pump. This one looks tiny at 1".

If one is using tubing and a 90 degree hose from the tube to the pump go buy a cheap hose at the parts store and steal the spring out of it.
The silicone hoses out there have a thicker wall but are not immune to being sucked in.

MFI maintenance.
Change every O-ring between the tank and the pump every year. The system can suck air from a tired,squished, hardened o-ring joint but not give you a clue by leaking.
Many "my pump is getting tired" can be traced to this issue.

Probably not a problem but if the project car takes years in construction perhaps those should be checked or replaced before putting it in the box.

Well its been in box. Just found that the primer side was pulling fuel thru the poppet and adding fuel at idle.Figure not issue under WOT since no vacuum then. Sure fubar the BV setting.LOL

With pump mounted lower and to side with belt drive I could not use my norm with 90* tube so have to go with piece of hose between hardline and pump. May not be issue but figure cut off problem even if not one yet. I have seen big pumps suck them shut or part shut before. A 7gpm pump might not be able to do so,why chance it right.

quote:

Originally posted by Dave Koehler:


MFI maintenance.
Change every O-ring between the tank and the pump every year. The system can suck air from a tired,squished, hardened o-ring joint but not give you a clue by leaking.
Many "my pump is getting tired" can be traced to this issue.

Three times I have seen people say the pump was bad only to find out there was a leak on the suction side of the pump, loose fitting, cracked fuel line etc.