1985 Chevy P30 fuel line help

[wolf_7669]

Alright, one more fuel line question.

The background: When I went to bring the RV home, she wouldn't start. After field testing all 4 lines comming out of the tank (3 - 3/8" lines and 1 - 1/4" line) by disconnecting each one and seeing if I could blow bubbles in the tank, I discovered the vent line was indeed connected to the engine supply as I could blow bubbles on all 3 of the other lines. I switched the vent line with one of the other 3/8" lines and was able to get her started and moved home without issue.

I can only possitively ID 2 of my 4 tank lines, the vent and the fuel return (it's the 1/4" line) so I could still possibly have my engine feed and generator feed lines mixed up.

So here's my question: How critical is it that I have my engine feed and generator feed lines correct? Or does it even matter since they are both 3/8"?

I don't want to find out the hard way that the generator's pickup tube in the fuel tank doesn't go all the way to the bottom or something similar.

[38Chevy454]

Have not looked at any manual, just going from knowledge. One line on the tank is most likely to a charcoal canister for emissions. One is vent that should connect up near top of the filler neck to allow filling fuel without backing up. One is fuel supply to engine of course. The other may be for generator, but it may not go to bottom tank. On many newer ones the generator line will not go below 1/4 tank so you don't run low on fuel to get engine started and able to move out.

Being carb and mech fuel pump on engine, you do not have return line from the engine.

[Harley1994]

Actually you could have a return line even tho its carb, it's the beginning of fuel management.

[Grandpere]

Originally Posted by wolf_7669

Alright, one more fuel line question.

The background: When I went to bring the RV home, she wouldn't start. After field testing all 4 lines comming out of the tank (3 - 3/8" lines and 1 - 1/4" line) by disconnecting each one and seeing if I could blow bubbles in the tank, I discovered the vent line was indeed connected to the engine supply as I could blow bubbles on all 3 of the other lines. I switched the vent line with one of the other 3/8" lines and was able to get her started and moved home without issue.

I can only possitively ID 2 of my 4 tank lines, the vent and the fuel return (it's the 1/4" line) so I could still possibly have my engine feed and generator feed lines mixed up.

So here's my question: How critical is it that I have my engine feed and generator feed lines correct? Or does it even matter since they are both 3/8"?

I don't want to find out the hard way that the generator's pickup tube in the fuel tank doesn't go all the way to the bottom or something similar.

The generator tube does not go to the bottom of the tank, that is to keep the generator from running the tank dry. So it is very important to identify which tube goes to the engine and which one goes to the generator.

My 87 is currently in the shop otherwise I could go out and look at it to give you an idea of which tube goes to the generator.

Russ

[wolf_7669]

That's what I suspected. I may just keep some fuel line handy in case the engine runs out of gas at 1\4 tank. Looks like a big pita to drop the tank by yourself.

[KSagal]

I have an 88 with a 350, mechanical fuel pump, and two tanks, so I cannot give detailed data exact with yours, but I will share some of the oddities that I found when I first got my Rockwood. (On a Chevy P30)

The hoses were all messed up when I got mine. There was a non-standard fuel tank solenoid that chose which tank fed the engine. Luckily you do not have this, because one of the first configurations I used had the fuel being delivered from tank 2, but the return line (Yes, return line with mechanical pump and carburetor) fed the return gas into tank 1.

I could not get it to feed from tank 1, so the result was to over fill tank 1. Odd that I was driving along and fuel started leaking from the overfull tank.

Anyway, the larger diameter fuel lines fed to the engine. Smaller ones return were return lines or vents.

I never did get it to feed from tank 1 properly, even though I could blow bubbles into it. I suspected that there may be some foreign bodies in the bottom of the tank, that would clog the feed line.

One of the vent lines did go to the charcoal canister.

Good luck.

[leadman]

A method to test the integrity of the fuel lines and piping is to use a hand held automotive vacuum pump with the brake bleeding canister on it. Disconnect the line and hook it securely to the fuel line to be tested. Pump the handle on the vac pump and it should draw fuel to the canister. Do not overfill the canister. You should be able to maintain a little vac on the line without pumping the handle once you have drawn gas to the canister. If you can not draw fuel up or maintain some vac you have a problem with that line, or it is not submerged in fuel.
I have seen the metal pick up tube break off the sending unit plate. I also have seen many fuel pumps replaced when it was a hose or fuel pipe. Some sending units have a piece of rubber hose on the fuel lines and these can crack or be destroyed by oxygenated fuel.

[JiminJersey]

Originally Posted by wolf_7669

I just wanted to verify what kind of battery should be used just in case the PO went with something different. There is just the one on it now, but the battery tray on that side is pretty big and looks like it may fit 2 batteries.

I would get the biggest, baddest, deep-cycle RV type batteries that you can fit in the space available, and join them in parallel to get a bunch of amps and stay at 12 volts. Some people use 2 or 4 6-volt golf cart batteries hooked in series, others just use two 12-volt guys. But it's almost impossible to have "too many amps", so to speak.

Your converter will keep them charged while hooked to shore power. Since your converter will PROBABLY not keep the engine starting battery charged, do yourself a favor and pick up a Trik-L-Start from BestConverters.com. It takes 2 minutes to install, and works by diverting a tiny amount of charge from the house batts to the engine batt to keep it charged up all the time.

The engine alternator will charge the engine battery, and MAY, repeat MAY charge the house batts too but I doubt it.

OTOH, the running genny will charge ONLY the house batts, I'm fairly certain. If I'm wrong, someone please correct me so we don't mess up the OP.

A lot of this depends on the sophistication and modernity of the RV converter - if you have the original, it's probably pretty dumb, but newer ones are much smarter, more reliable, and not all that expensive for the benefit they bring.

[wolf_7669]

Originally Posted by JiminJersey

I would get the biggest, baddest, deep-cycle RV type batteries that you can fit in the space available, and join them in parallel to get a bunch of amps and stay at 12 volts. Some people use 2 or 4 6-volt golf cart batteries hooked in series, others just use two 12-volt guys. But it's almost impossible to have "too many amps", so to speak.

Your converter will keep them charged while hooked to shore power. Since your converter will PROBABLY not keep the engine starting battery charged, do yourself a favor and pick up a Trik-L-Start from BestConverters.com. It takes 2 minutes to install, and works by diverting a tiny amount of charge from the house batts to the engine batt to keep it charged up all the time.

The engine alternator will charge the engine battery, and MAY, repeat MAY charge the house batts too but I doubt it.

OTOH, the running genny will charge ONLY the house batts, I'm fairly certain. If I'm wrong, someone please correct me so we don't mess up the OP.

A lot of this depends on the sophistication and modernity of the RV converter - if you have the original, it's probably pretty dumb, but newer ones are much smarter, more reliable, and not all that expensive for the benefit they bring.

Looks like your spot on with the converter I currently have. Shore power is only charging my house battery, and alternator is only charging the engine battery.

Will definitely look onto the Trik-L-Start. It will be nice to have both batteries charge off shore power.

[ftv37]

On my 85 there is a pusher pump either in the tank or on the frame rail by the regulator
mine was in the tank.On our first trip she would run great on flat ground but as soon we get to a hill she would quit,I did not know about the tank pump.The pump on the engine
block is not enough to pull fuel at that angle. Good Luck

[wolf_7669]

Originally Posted by ftv37

On my 85 there is a pusher pump either in the tank or on the frame rail by the regulator
mine was in the tank.On our first trip she would run great on flat ground but as soon we get to a hill she would quit,I did not know about the tank pump.The pump on the engine
block is not enough to pull fuel at that angle. Good Luck

Unfortunately mine does not have an electric pump, but it will be one of the first mods I do. I've noticed that with just a mechanical fuel pump she's a bit hard to start after sitting a few days, like most of the fuel in the lines drained back in the tank (our driveway is inclined).

Thanks to the wealth of knowledge on this forum, I've got Chevy's field fix instructions for adding an electric fuel pump. I'll also do the tweak another member did and add a momentary on switch for the pump so I can fill/pressurize the fuel line before starting the engine so it'll be easier to start.

[ftv37]

If was not for the wealth of knowledge on this forum,We would have not made our cross country trip without much trouble

[whem2fish]

and do the disturber mod in 10 i have never saw a fleetwood with out a holly pump on the pass side in front of the rear end

[spritz]

I have a 82 chev P-30 Fleetwood Pace Arrow with the 454-4 barrel. She has 2 tanks a 70 in the rear in front of the genie and a 30 in front behind the passenger wheel. There are 2 fuel filters in that area behind a protective plate. I found out the hard way on our first trip out both tanks both had clogged filters. A 76 mile tow (paid by insurance) and a $125.00 Bill.
There is also a filter on the carburetor. I have replaced them 3 times in the last 4 years just to play it safe as she had sat for the previous 6 years. I have replaced the one on the carb Twice.
I have also used several Lucas fuel treatments in both tanks.
Ours also has 3 battery's 2 house and 1 start. They have always been charged by the inverter.
She might be a 82 but she goes like a bat out hell now, even towing the toad.
Just my 2 cents worth
Tim