Please help with C30 454 fuel delivery problems and stalling

[drumvirt]

Can ya'll help me with some C30 fuel problems?

I've had my only square body, “Brutus Dooley”, an '85 C30 454 dually, camper package, strong as an ox,for 20 years. He'd traveled 73,800 mi. when I got him. Now, 20 years later, he's totallin' 113,500. His one bad habit is fuel problems, anomalies, or whatever, and he decides at the worst times to embarrass me and pass out in the middle of rush hour traffic, out of breath (breathin' vapors?) on the most mizzzzerably hot days. And he's slow about wakin' back up! I got to know the local tow truck driver, Bobby, after a while, and asked, “Bobby, can I buy a season's pass?”... “NOPE”!

So, I took him to Dr. Autto who referred Brutus to Dr. Harlow (real last name) the president of the regional Quadrajetic Society. Dr. H performed an operation on his Quad and immediately observed an incorrect gasket from a previously botched operation. He went back to his cooler for a transplant and returned with a 5gal. bucket, 2/3rds FULL of well preserved, used, Quad gaskets! He quickly flipped thru em' 'till he found the CORRECT one, transplanted it, then adjusted Brutus' Quad. Well, he ran smoother, around 25% farther, but still passed out in the heat.

So, I tried a big new BeCool radiator,(helped some), and rerouted his fuel line arteries away from heat sources to help eliminate his passing out. Only helped a bit. Different Dr. suggested I have a dual tank transplant and I did. Brutus had an electric 'pacemaker' pump installed before I knew him and Dr. H advised me to keep his pressure down to around 6 psi so I installed a pressure regulator and that regulator didn't require a return line so I kept it returnless. I also transplanted his pump with a Carter that had strong vertical draw to eliminate loss of siphon and pressure which helped him revive more quickly. Dr. also advised I keep his (pardon me) 'exhaust pipe heat' to a minimum, so I formed an additional longer heat shield over his fuel arteries and pump, and covered the shield with heat reflective material from Summit. By now, after some years, he was doing better, with only an occasional fainting spell, in the very hottest weather, but still cursed, not cured.

At some point, I suspected Brutus right side was not drawing fuel, so I began only using his left tank. Then his regulator (one which allowed for choice of return or no return)malfunctioned so I did another regulator transplant along with a tank selector switch. The regulator was from the same manufacturer and looked identical but I failed to notice that this was a different model that required a return line to regulate properly. So I reconnected his long dormant return line. The newly reconnected return line allowed the regulator to work properly, but it immediately began to cause fuel to run out of the small vent in the tank selector valve, no matter if it was switched to left or right tank. It didn't leak before I connected the return line. I can get anew return less regulator and eliminate the leak. But am I correct that a functioning return line might also solve Brutus' fainting problem I've been wrestling with for years, likely due to my lack of automotive knowledge? Btw, Brutus has sat for about a year now.

So, I have four thorny problems that I'm asking for y'all's help with: 1) Brutus still occasionally faints in very hot weather, especially when stopped or crawling in traffic.2) Selector valve leaks when return line is hooked up. Selector valve replacement necessary? Both my tanks are full, one is well aged (my bad). Will they need to be drained? 4) How do I determine if my tanks are vented properly? If not, how do I correct it?

Any other suggestions?
Thanks in advance for considering this.

 

[fast 99]

Didn't read the entire post just bullet points at end. Too long winded for me. First thing check fuel pressure and volume.

 

[drumvirt]

My pump pressure can go 2x what I need, down to 5 or 6 psi. I'll check volume tomorrow. Thanks.

 

[Ricko1966]

Didn't read the entire post just bullet points at end. Too long winded for me. First thing check fuel pressure and volume.

I didn't even read that far.

 

[Chevy 88]

Like, whats the short version of the problem?

 

[LeperGnome87]

Sounds like a vapor lock problem. Either that or maybe a collapsed return line? Hard to tell, could always install new tanks or maybe even do a under the bed tank bolt in and run new lines and filters. I know some people have done a swap from k5 blazers to a 30 gal tank. I would definitely recommend getting rid of the selector valve, those always go bad and never work right. I know they make a replacement for it. Try a FSV1K i think

 

[Ovals_and_Bowties]

If it's anything like my 85' C10 there should be 3 lines. Fuel feed, fuel return, and vapor. Vapor should go to a charcoal can near the radiator somewhere. In terms of telling if the vent line is clear: Should be able to unhook that line, pull the cap off of which tank you wanna test, have yourself or an assistant listen at the filler neck while someone blows in the line. Should hear it moving air.

Pull the fuel cap off the next time he faints. If his tummy sucks a big old breath of air in the fuel cap vent ain't letting air in. Try driving him with the cap a little loose and see if he still passes out.