Fuel Delivery issue

Sounds like the fuel pump. I know you replaced it but that doesn't mean it's good. Chinese parts these days...

Get a block off plate and a Carter electric pump mounted to the frame and be done with the mechanical all together.
--
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455
 
They all have pro's and con's

As for fuel pump installation you want pumps as close to tanks as practical. Electric Fuel pumps can fail, so running an electric on each tank you
should always have a 2nd pump/tank to fall back on.

Most people go to 2 electric fuel pumps to solve vapor lock problems. The mechanical pump is usually the more reliable pump other then vapor lock
issues.

Wiring in multiple pumps takes a little thought as far as relays and wiring and such. Making sure pumps
Do not run when they should not.

As far as fuel injection, there are lots of options and some performance improvements, But you are also introducing failure points. So can be a
trade off.

Fuel injection will not fix the problems you are having now. Something or multiple things are going wrong.

You are located in atlanta, it would be good to have a second set of experienced eyes looking over the problem. You dont want to spend money on
fuel injection if something is majorly wrong with engine.

--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
It sounds very much like vapor lock to me, we've had it when it reaches about 85 degrees or more on a consistent basis. We too have the exact same
setup with the aux electric pump (installed by JimB as well), and it works every time to correct the issue long enough to switch back to the regular
tank. I've been slowly doing some additional things to the coach to try and cool down the engine box little by little to see if we can prolong the
time it takes for the vapor lock to start. I figured I would post everything at once, when I have some sort of results.
--
Chris S. -
77 Kingsley, 3.70 FD, mostly OEM -
S.E. Michigan
 
For 20 bucks and 30 minutes of time, I'd put in another new Carter 6108 mechanical pump and run the boat tank to see if that makes any difference.
You didnt say if the fuel lines were all replaced recently. Possible one is gummed up if its old, one of the in line filters other than the carb
filter is clogged, or hoses which are cracked/damaged/pinched.

Another new mechanical pump and the known good boat gas can will rule out all that other stuff (selectors, elect pumps, relays, wiring several yards
of fuel line) back toward the tanks at a minimum.

Then if that runs well, start eliminating things one at a time working back.

Id also take a good smell of the oil and check the engine oil level to make sure one of the mechanical pumps didnt puke fuel into the crank case. oil
that stinks like raw fuel is no good.
--
77 Royale, Rear Dry Bath. 403, 3.55 Final Drive, Lenzi goodies, Patterson carb and dizzy.
Mid Michigan
 
After vapor locking on I 75-85 at the Brady curve one Monday afternoon at 5P I heal;ed my problems pretty much permanently with this setup:
http://www.gmcmhphotos.com/photos/g6198-cane-9-creek-rv-park-heflin-2c-al.html
A pair of Mr Gasket electrical pumps and a relay to switch. They have built in backflow valves. Discard the sup[plied filters and buy a pair of the
Wix exact replacements, the originals will looseb at the swaged fitting and leak. Blankflange the mechanical pump-. I'm off the rest of the week to
VA, but back nect week, PM me of you have questions.

johnny
Braselton

--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
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