fuel starvation issue

I have a 330 Desoto hemi that will not start. I dis-***ambled the fuel lines and checked for suction at the fuel pump. I seem to have no suction from the mechanical pump(Brand new). I took the pump off and cleaned and blew it out. Alsl bench tested the pressure (all OK). What else could be causing the lack of fuel to be pumped to the carbs?

 

worn cam lobe for fuel pump?

 

is it the correct pump? you said you bench tested it and it was fine.....but is the cam or whatever actually pushing on it?

 

I am nervous that it might be the cam lobe. How do I check for that?

 

not sure, not familiar with that motor. but there has to be something that is supposed to push on the fuel pump. maybe take off the fuel pump and insert a wood dowel , turn over the motor and see if it moves?

 

Is the pushrod missing? I've heard of people tossing a pump back on without pushing it into position or leaving it out all together.

 

Pushrods is there. I cranked the engine and the lobe that pushes the pump is turning eccentrically as we'll as it does not look to be wiped or scarred..I might take the pump apart and check the internals.

 

I don't mean for this to sound stupid,,,but there is gas in the jug for the pump to draw from ,,right?
sometimes we all get excited and forget the simple things.
By the way,,your engine looks beautiful,,really impressive!!!
If the eccentric is pushing the pump lever enough,,and it not pumpin fuel,,it sounds like a bad pump, But,,I ***umed the pump is brand new,,right?

Tommy

 

It is the correct pump ,,right?
If the 330 is like my 291,,it doesn't have a lobe on the cam,,but a bolt on eccentric like the small block Mopars.
And,,the pump takes an adaptor to reach the eccentric,,because the factory timing cover mounts the pump in a different location slightly.
If it is an aftermarket pump,,I think there is an add on part to make the pump arm length correct .
Check that as well.

Tommy

 

thanks Tommy..Yes the pump has the adapter, gas is in the jug and the adapter is there for the fuel pump I'll add pics for help. It ran fine several times for about 30 minutes total...

 

do you have enough venting at the fuel tank?Maybe the pump wants more venting than the tank vent allows

 

I just re-installed the fuel pump with a bit of grease to see if the arm was being pumped/engaged.. It appears that the arm is pumping. Then I replaced the fuel line and left the hard line from the pump to the carbs off... No fuel is coming out. It intermittantly pumps up from the fuel cell, so the pump is ****ing fuel intermittantly to the pump but it does not push it past the pump...Bad Pump?

 

Is this a pump that has a removable base that bolts on?
There are really just some bellows type seals in most of them.
If it is a brand new pump,,,it is time to return it and get a new one,,should not have any problems this soon.

Tommy

 

try a small container of fuel at the suction end of fuel pump effectively byp***ing the tank and line. if it picks up fuel the problem is probably between the tank and pump

 

How can you tell its picking up fuel from the tank if no fuel is headed out ?
The lines can **** air but not leak fuel. Like a hole in your drinking straw.

 

"New, only means Shiny"

4TTRUK

 

That happened on my Valiant. It had been sitting for some time and fuel varnish plugged the pickup in the tank.

 

so, engine still on stand or in car?

 

Still on stand. The fuel line from the cell is clear so I see fuel being ****ed up to the pump but not past the pump. It sounds like the pump itself but it only has about one hour on it.

 

OK, so it's not the tank. My error. Perhaps the arm on the pump is only touching the eccentric on the cam. May sound dumb, but possible if the pump isn't the right one for your motor. It could be just off enough to be an issue. Pull the pump and crank it by hand. If it works then, see if the pump is correct for this motor. I made a custom cast timing cover for my 341. I reworked the pump mount on the casting to use a 318 pump since the location is slightly different in order to make the arm connect with the eccentric. The arm on the 318 pump looks the same as the 341 unit, but different enough to be an issue. Hope this helps. Bill

 

Been a lot of problems with F/Ps lately, new, rebuilt OEM style. On my Chr I had a new one that wouldn't work. A buddy had a new one on a 354 that the arm wouldn't actually contact the eccentric, too far forward. He bent it slightly to make contact. A few weeks later the arm came off the pump & broke the timing chain. I used the HH adaptor & LA pump to solve the problems I had. On the Chr the adaptor moves the pump out about 1/2" so contact is @ the right point on the arm.

 

I used the same adapter and LA pump.. If you look at the pictures you can see the only portion contacting the eccentric is the far end. Almost the size of a fingernail. Is this correct?

Here she is running like a champ a month ago
http://www.youtube.com/watch?v=oZ5XB6ggzaM

 

Didn't take it off to check.

 

I'd say
You narrowed it down to a bad fuel pump. So next step would be to try another. You could switch it over and use an electric pump, don't cost that much. But trying another pump is about the only option you have. These things go bad.

 

try pushing fuel through it. the check valves may be stuck.