Dlo3575

My son has a 69 Charger that we put a new tank, fuel sending unit/sock and inline fule bowl filter. Car cranked right up and drove fine for two weeks. Then one day it did not start, I noticed that if I added fule to the carb direct (via magic cup-o-fuel ) it fired up and ran. If I take away the fuel from the cup it died. So I assumed it was a bad fuel pump. Now I assume it is a 318. The aftermarket Edlebrock intake says 318/360. I bought a 318 fuel pump and it looked about the same as what came out. I installed the new one. It still won't crank. I filled the fuel line to the carb twice trying to refill the bowl, but no dice. There is some fuel in the bowl but I still have to force feed it to run. After a 1/8 a gallon or two big gulp cups later, I figure I have a bad fuel pump. I replce it and still it is doing the same thing. So I assumed it was a bad carb. New Edlebrock and no dice. I still have to force feed it. I prime the bowl (feed gas down the inlet fuel line to the carb until it can't take no more), and it runs great, until it uses all the fuel up. I am about to pull my hair out. My son is frustrated too (I look like a putz). EVERYTHING fuel related is new. Here is my observations. The second fuel pump seems to actually fill the fuel bowl this time. But fule just doesn't seem to make it the last 8" to the carb. Is there a possibility this is not a 318 but a 360 if there is a different size fuel pump for a 360? Or is this a 318 and the problem lies elsewhere> ? I assume that i should be able to disconnect the fuel line and turn over the car and it should spit out go juice like a guy in a porno! When I try that, no go, dry as a bone. I guess my main question is, is there something funky about priming a fuel pump on MOPARs when installing a fuel pump? Is a 318/340/360 fuel pump the same? ANy help will be greatly appreciated

MercuryDon

Try running a hose from the pump into a gan of gas and see if it gets gas then. If it does then you have a fuel blocksge between the pump and the tank. 318 and 360 pump should be the same.

68Polara500

I'm experiencing something similar with my '68 Polara 318ci. I'm on my second fuel pump and after short order of running great, the pump stops pumping. I've done everything I can within my tools/gear troubleshooting including assessing from the fuel pump to the carb, and from the tank to the fuel pump, ensuring fuel flow by siphoning along the fuel delivery components. I even changed a forward section of corroded fuel line. I'm now convinced that although the tank was steam cleaned and the fuel sending tube was soaked in solvent to ensure it was clog-free, the fuel lines from the tank to where I changed it is the problem. I'm about to upgrade the fuel lines. I hope your problem might be a simple solution as I hope mine will be.

Dlo3575

Great idea. I posted this last night right after coming in out of the garage totally frustrated. So sleeping on it over night and the generous postings has given me a couple ideas. I will try the gas can and a hose to the pump (bypassing the tank and fuel lines) as well as a hose from the pump, straight to the carb (bypassing hose and fuel filter). This should identify the culprit! Thanks for the suggestion boys!

440roadrunner

I've read about this or similar problems "around the www." Many blame it on "modern gas" which boils off. Donooo

I'd FIRST check that the tank is actually getting vented.

You might consider "throwing in the towel" and installing an electric pump.

All small block pumps, 273/ 318/ 340 /360 fit and operate on the block. Only difference is changes to lines/ fittings/ pressure/ capacity over the years.

Another thing you might consider is a "vapor return line." I'm BIG on these. First one I ever saw and had was factory on my 70 Roadrunner. Wix makes this handy to implement, they make a 5/ 16 and a 3/8" metal throwaway filter with a 1/4" return fitting. 33040, 33041. Just plumb a line back to the tank. If you don't have a "spare" vent to hook it to, you'll have to use your own ingenuity. I'm currently fixing up a 67, and i'm going to silver braze a fitting into the filler neck in the trunk.

Just stuff a tube down the filler and hook it to a little CO2 (your wirefeed). You can also drill the hole through the fitting AFTER you attach it.

TVLynn

Check the rubber hoses from the fuel lines to the tank !!!

68Polara500

I'm quoting myself to update on the problem I've been experiencing and solution I just found out. This may help you.

I troublshot/changed components all I could to determine why my fuel pumps were failing. The cause was either:
- between the tank and the fuel pump (perhaps blockage/corrosion somewhere -- I did change a 4' section with a small leak, tank had been steam cleaned, fuel sending tube cleaned in solvent);
- between the carb and the fuel pump (I tested for gas coming through, but none);
- or the eccentric (that drives the fuel pump rocker arm) on the camshaft. When I have the fuel pump off, I can feel inside the camshaft/timing chain space. The chain is a little loose, but not the problem. I can't see or touch the eccentric except I can sort of feel it through the rocker arm on the fuel pump when lining up to install.

I don't have the tools or gear to take it any further, so I had it flatbedded yesterday to my local (old school) garage (the owner has a '65 Chrysler Imperial -- I think that's what it is.) The mechanic just called me to advise that the problem is with the eccentric on the camshaft. It's worn and not doing its job. To change it will take a couple of weeks to find the part, then all the labour to take everything apart. Since the timing chain is still ok, the easy and cheap solution (thank god there is an easy/cheap workaround) is to install an electric fuel pump back at the tank (back there to avoid any potential for vapor lock), so that's what'll happen on Monday. When the timing chain eventually needs changing, I'll consider replacing the eccentric while at it to revert back to original design.

So, consider the eccentric on your camshaft as a possible suspect.

scotts74birds

I'm not familiar with that car, but are there rubber lines near the top of the tank that could crack, and have a good pump suck air?

bremereric

I agree with Don...suck it from a gas can....

Dlo3575

Problem solved!! The gas can idea was great. Sure enough it indicated it was coming from the fuel pump back. SO I focused on every inch going back to the tank. Guess what I found? The rubber fuel line coming off the new tank and developed a kink! I cut the slack out and problem was solved. With everything new (tank, sending unit, pump, fuel line and pump), who would have guessed a .40 fuel line kink>???? My son has his car (and faith in dear ol dad) back in working order! To all you MOPAR guys, thanks. Stepping back and reading your posts cleared my head and got the problem solved. Thank you!!!