can fuel line position cause vapour lock?

[BobK]

Last summer I had issue's with vapour lock.
I redid my fuel supply lines leading to my TPI before the problems started.
The fuel supply line now comes up from the frame rail,makes a 90* turn and runs parrallel to the ground for about a foot,then up to the fuel rails.

After the vapour lock started I insulated the fuel supply line with a reflective cloth insulation...did't help though.

The times it did happen the ambiant air temp was in the 90-100* area and the truck was pulling a loaded trailer.

Could the fuel be vapourizing in the fuel rails?

 

[dyeager535]

TPI should not have a problem with vapor lock, that's the whole point behind the fuel return line. (constantly circulates gas like a radiator.)

As a matter of fact, if it did indeed vapor lock, the engine would die. No pressure=no injector spray, no injector spray=instantly dead engine. You'd have to confirm you were losing pressure first, then if because of vaporized fuel, or something more likely, such as a weak fuel pump.

The only place I'd be concerned with the lines picking up heat is right near the exhaust manifold, and it doesn't appear yours are in close proximity, at least not for long.

The first page here http://dyeager535.topcities.com/TPI/index.html shows a couple of pics of my fuel lines, and there is no issue with those. At least somepoint in their run in a typical install they will have to run close to the exhaust, as long as it's not super close for a long run, it should be fine.

 

[Leper]

Make sure your fuel return line is good and not plugged.

 

[BobK]

My symptoms were loss of power then once I took my foot off the gas it would die.
I would wait 10-15 minutes then she'd start right up again.And again I will say this ONLY happened when the ambient temps were in the 90-100's.

I'll check my return 1st.

I also am a little weary of my fuel pump.My gauge at idle says I have plenty of pressure but since the gauge is mounted to my fuel rail it's a little hard to check while the eng. is under load.

Thanks for the suggestions though.