Weird fuel/hot thing.....

[KivaKid]

OK....Help!

1) This *kinda* sounds like vapor lock...
2) It's definitely heat related.
3) Fuel pump and filters are new.
4) Carb is freshly rebuilt.
5) Gas looks clean coming from tank.

(Also, lots of pumping to start in the morning.)

Occasionally if I drive a while in higher RPMs, and let the engine get hot (just in the middle of the gauge) and get off the highway or turn off onto a side slower street, she'll start to stall a bit. Usually I'm stopping somewhere, so after sitting she's fine. Yesterday, this happened, only she stalled and couldn't get her started again. She would fire for a second but then die again. No success opening the filler cap. I had her towed near the house to the guys that did the fuel pump a while back. I went there early this morning and she starts/runs fine. Could the carb be getting too hot and boiling fuel....or is that glass fuel filter I installed *before* the new fuel pump getting too hot?? Hmmm....Maybe the rubber lines to the fuel pump and tank return are too close to the exhaust stuff??

[ February 02, 2003, 07:37 AM: Message edited by: KivaKid ]

[graham]

When it dies, is there fuel in the carby? Lift air cleaner cover off and manually pump accelerator linkage. Any fuel?
If theres fuel there then could be ingition prob. I had similar symptoms and ended up being dicky pick-up coil. Worked fine until it got hot then quit. No spark No go.

[KivaKid]

There was definitely no fuel getting up to the carb, my buddy looked at that, and undid a fuel line at the filter and nothing...

Also, in the clear filter before the fuel pump, there was no fuel. On cranking it would kind of fill up, but would drain back when we stopped cranking....

[ February 02, 2003, 07:57 AM: Message edited by: KivaKid ]

[steven79]

check your gas cap it might not be letting air in the tank. if you take your cap off does it make a loud hisssing sound when hot? if so run it with out the cap to see if it still has the problem.
My old dodge pick up colapsed the tank one day due to a bad cap.

[mechanic58]

Vapor lock can be so hard to diagnose...my wag had similar sypmtoms...stalling, hard to start etc. But it ended up being a leaky power valve. Mine was flooding...not starving. Same symptoms. Where do you have your fuel lines routed?

[graham]

Originally posted by KivaKid:
Also, in the clear filter before the fuel pump, there was no fuel. On cranking it would kind of fill up, but would drain back when we stopped cranking....Fuel pump sucking air, a leak at the new fuel pump or there's a blockage in the tank.

[KivaKid]

Also!! I have been smelling a bit of gas lately!!?? I thought it was my can in back but took that out.

When I went up to the auto place this morning, I just poured a little gas in the carb, then started her. She coughed just a little then ran as normal. I imagine getting all the air in the fuel lines out. I imagine that the pump had lost it's prime or had air. Still, what made it lose that prime....vapor lock? Carb too hot? Maybe there IS a leak somewhere....

The rubber line from the metal line on the fender to the fuel pump has the glass filter in it. It runs 3-4 inches from the exhaust manifold. The rubber may not be as much of a problem as the glass/metal in the filter....!!??

I think I"m gonna get her to the house in a bit and do some serious fuel system reapirs/mods...

[ February 02, 2003, 08:26 AM: Message edited by: KivaKid ]

[4DWUDS]

I would lose the glass filter to start. A broken glass filter and a hot manifold dont mix very well. Try one of those extra thick carb gaskets with the rubber grommets around the bolt holes to help from heating up the carb.

[M1Garandfan]

Dang "Kiva" that sounds like my truck! I was able to put fuel in the carb bowl and could hear it boiling!

[KivaKid]

I got the Wag home, and Sea-Foamed her. Hopefully, that will get rid of some carbon build-up that could contribute to heat. Call me crazy, but I noticed a pretty significant power difference. I'll Sea-Foam her again soon. Now I have to:

1) Get rid of that glass filter, now that I know the fuel is clear.
2) Make sure my stock filter is positioned with the return line barb up.
3) Run longer lines further away from the exhaust manifold.
4) Put some sort of heat wrap around the fuel lines.
5) Hope that my carb isn't boiling away the gas!!

[M1Garandfan]

Sea-Foam?

[KivaKid]

Sea Foam (http://www.seafoamsales.com/)

[davez26]

Kiva, I wouldn't rule out vapor lock. You are in prime territory. I know. 5000 above sea level, Oxygenated fuel that vaporizes at a lower temperature formulated for cold temperatures and a 65 degree day. Heat and winter gas are one bad mutha. On mine, the best I can figure is that fuel was picking up heat and vaporizing in the lines and causing a blockage. I built a heat shield for the metal lines @ the frame, covered the metal lines form the frame to the fuel filter with Nomex.(I think it is called Nomex. It is like this fabric stuff, that is heat and flame resistant, like fire suits are made of. I got it @ a speed shop.) A pusher pump on the frame rail helped quite a bit, but did not eliminate it, maybe it was a cheap pump. I finally got some wise idea and put an in-tank pump in and things have been okay since.

[KivaKid]

Interesting, really seems like vapor lock to me, too. I read in my tech manual that the return line barb on the filter must be positioned upwards. Mine was not....it is now! I also took out the clear Spectre glass filter I had before the fuel pump, and ran the new rubber line further away from the exhaust manifold. I'm gonna Sea Foam her again, too, to help get rid of carbon build-up which can lead to extra heat. I'm going to also wrap my fuel lines with something....maybe the Nomex. Also, I may bring in some cooler air to the carb by putting a tube from the air cleaner to the front back on.....weird stuff..... :eek:

[ February 03, 2003, 04:54 PM: Message edited by: KivaKid ]

[timmirvin]

Man, the things I am learning on this forum!!!!!

It just never occured to me about having the fuel filter return line "up." Makes sense tho.....

I love this place!!!!!

tim