I don't know where else to put this so if the moderator wishes, please move it to its appropriate spot.

Built a '68 Mustang 5.0 AOD out of a '90 Lincoln LSC converted to MASS air using RJM harness.

So after much research I used one of the recommended fuel pumps (new) which is the Airtex E2000 out of a late '80's F150 IIRC.

It was plumbed with the fuel filter (Ford EFI) and screen before the pump.

It all worked good for several 1000 miles and then started howling after a 150 mile hard run (first long trip) so I swapped it out and it began to howl and quit pumping before I got home. Sit on the side of the road, let it cool down and back on the road.

Called Airtex tech support and they said replace the pump, plumb the filter after the pump and you should be good. It should be able to lift 18" max.

I swapped the pump, used all of the nifty quick connects except for the suction side of pump, moved the fuel filter and make a 550 mile trip in hot weather (250,50,250) and no problem except for some surge that goes away after the first tank of fuel.

So we take off on vacation and the pump starts howling and it quits 500 miles from home. I notice that I can change the tone of the howl by putting my finger where the suction fitting screws onto the pump. Tighten it up and we run several hundred more miles.

Get up this morning drive across southern Colorado and it starts howling again. Replace o-ring under suction fitting as it never appeared to me that the cross section is big enough to seal on the bevel. Runs for a while and starts howling and quits.

Replace pump in Pueblo Colorado. Starts howling and quits within 30 miles although that pump appears to have been a return and had been installed based on the gasoline smell and worn box. Let it cool and go on.

So here is what I have:

New pickup in new tank

Rubber 5/16 fuel line stretched over 3/8 nipple on tank end and clamped onto EFI quick connect barb with 2 clamps

New pump mounted horizontal 1/2 way between top and bottom of tank. It is sitting between the body and differential.

Stock quick connect fuel line fittings and EFI hose to new Ford EFI filter.

Rubber EFI hose to 3/8 steel line (original line flushed for about 1 hour) going to rubber EFI hose and fittings to fuel rail.

Return line 5/16 new from rail to tank.

No kinks in lines.

Full tank of fuel does not fix it.

Exhaust pipes are a foot away from pump.

When pump howls (vapor locks?) it is barely above ambient but always does it when hot. It will change tone if you pinch the line on the suction side.

New fuel cap and no pressure change when opening it and no effect on howling.

Tonight I replaced the line between the tank and pump with EFI line and a brass fitting that is 5/16 on one side and 3/8 on the other so I don't have to stretch the line. I have not tested it.

So what am I overlooking?

 

I will be doing an RJM conversion this year, so I'm very interested in this. Sorry I can't help you out, although I might try a different brand of pump. Keep us informed.

 

I have learned more about what is happening.

I am vapor locking the pump and the new improved one does not solve the problem.

We stopped in a NAPA in Steamboat Springs after it quit going over the pass leading into town. One of the counter guys said the problem is relatively common and try adding ATF to increase the vapor pressure of the fuel.

It only quit 2 or 3 times on the 1K+ miles going home so it was better but it is hard to judge what did not happen.

So the current theory is to go with something like the Tanks Inc in tank PA series fuel pump.

I wish I knew for sure that would fix the problem before spending $250-500.

 

I have had vapor lock issues before with electric fuel pumps. Make sure the incoming line is nowhere near a heat source. Simple plumbing insulation helps. In tank is best, otherwise, keep the pump as close to the tank as possible.