So as a self proclaimed and tortured apostle of lost causes, I have obtained a 1976 GMC motorhome Eleganza2, over which I am steadily going broke. However I have undertaken to remodel the interior myself and remove ALL the Particle board (thereby lightening the load by several hundred pounds. However, My entire knowledge of the Olds455 engine could be written on the back of a postage stamp with room left over for the Gettysburg address.
I'm guessing that long ago the mechanical fuel pump gave out and some DIY devotee stuck in a Chinese electric pump. Good, eh? Excpt that the tanks on a Eleganza2 are right at the stern (ex Navy - sorry) and the force required to bring it for'd (did I mention - ex navy?) is greater than the gravity of Newtons apple. First of all the suspension of the vehicle, hereby known as THE BUS, (other expletives have been applied but will remain conceiled in deference to any female gender caught reading). The BUS rides on an Air suspension system riding on two (one each side) double air cones that eventuall give up (don't we all). therefore the BUS rides lower at the stern (did I?.... I think I did). Therefore the cheapo imported electric pumps are not capable of defying Newtons Law.
So the bottom line is this: What should I aim for in the specs of a decent electric fuel pump for this monster? I apologise for the garrousness of the intro but I neveer could resist a forum (that's a lie just in case you go looking for further offering s from me)
Regards to all
Bart

 

Welcome to the site. I don't know the answer to your fuel problem, but I'm sure someone else will. Reason I responded is I love your humor. I hope you have many good times with your "bus".

 

Where is the fuel pump mounted?
Most electric pumps work best when they are mounted near the fuel tank.
They do better at "pushing" fuel to a distant engine, than if they "pull" fuel from a distant tank.

 

Welcome aboard.

Maybe an electric pump at the rear to push fuel towards the front, then a mechanical pump in the factory location (fed by the electric pump) to help the fuel continue its journey to the carburetor.

 

Pumps need to be mounted below the fuel tank also.

 

Welcome. A good friend of mine has been rehabbing his 1973 23ft GMC for a few years now. The airbag suspension is one known problem and he's gone through and replaced all of it. The aftermarket support for these motorhomes is amazing (and some of the formerly unobtanium parts they've reproduced cross over to Toronados). I agree that a good quality electric pump near the tank is a good idea. You should still run fuel return, possibly with a regulator near the engine. You certainly can't go wrong with Carter or Holley.

 

If you replace the mechanical fuel pump or get a better electric fuel pump and mount it down low by the tank you'll be set. Post some pics when you can.

 

Make sure your new pump is compatible with the alcohol blended fuels we are all forced to use, and that any replacement fuel hoses are also alcohol compatible.

 

I found Carter to be a very reliable pump. There are several different ones with various flow ratings. Be sure and get one that is right for your application. I would also suggest installing an automatic cuttoff wired to an oil pressure switch. It is good insurance.

 

Welcome aboard; from one former swabbie to another! Sounds like you have quite the challenge ahead of you. I agree with Glenn, redoldsman, the Carter pumps both mechanical and electric are very good choices. A fuel pressure gauge at the carburetor, at least for initial set up is a must when using the Rochester QuadraJet carburetor as they do not tolerate high fuel pressures, I think 4 to 6 psi is the goal. Good luck with your project.

 

Welcome to the site, lets see your toy.

 

Thanks for your offer of enlightenment - you'll go on my Xmas card list.
The pump(s) - (When I bought it , there were two in series though why anyone with one once of grey matter would consider a defective pump to pass fuel by just sticking in more more pumps I suspect if I had not been suckered in the array could have turned into a dozen or more. So the last pump claims to be 70 LPH (Litres) which I believe is nor man enough for the job even if it did work. It didn't so we'll never know. The first attempt (I believe was to put a pump right by the fuel tank and I agree, that's where it should go to push the stuff uphill. However when that didn't work, I believe it was someones idea to add an additional unit right up there by the carb.. BTW on the day of purchase, the Bus ran all the way from Springhill (Florida version) till the first major hill (about 30 miles down the road), and. coughed it's way up it. By the second major hill (30 miles further on)- I needed a tow. Which gave cause to an idea that the seller had both tanks half full and at the time I thought that was very generous. After come contemplation that fact tied in neatly with the fuel problem currently being experienced.
So there we have it - I still feel all I need is a decent pump. OR ...... I need the tanks scoured - which is a bummer.
Regards
Bartleby

 

I would try the new pump first, mounted as close to the bottom of the tank as you can.
If this thing has been sitting for a while, fresh fuel may make it run much better also.