So I am trying to get started a 1972 F350 with the 360, Brand new starter a good hot 550cca 685amp battery but it rolls very slow, as if dead battery. Any ideas on what AMPS I actually need to turn it over fast enough to try and get it started?

 

Disclaimer - not a mechanic

In general, the higher, the better, but I would think that battery would work.

All you cable connections tight and clean?

Do you have a jump/booster box that might give it some added starting power?

 

Check your cables. Make sure you have a good grounds.

 

Plenty of CCA for that engine. High CCA are only needed for extreme cold. See what the voltage drop is in the grounds and cables. Very common in old cars and trucks. (If any of the cables are original or even just sort of old they need replaced.) If voltage drop checks out OK, a starter current draw test.

Excessive ignition advance will also cause slow turnover. Temporarily disabling ignition will reveal this.

 

Clean/replace the connections. Adding more grounds will only make your electrical life easier.

I ran grounds to the frame and the engine (at the alt. mount). There is also one to the cab.

 

Timing can give you that hard to turn you describe. You can pull the plugs and see what happens.

 

Ok wires all good, tried another battery spins a little faster, actually fired up and ran with starting fluid. Not getting gas now. I have gas to and into the fuel pump, and fuel comes out of the fuel pump, but it is a weak and bursting stream that is not constant. Any ideas on pressure the mech fuel pump should put out? I think I need to just find the cover plate, to put in place of mech fuel pump and get an inline elect fuel pump. Any thoughts on this could be help full and thanks for the reply's guys.

 

FYI if it is an original pump, it will have a spin off fuel filter on the bottom which could be clogged up. I just price checked a new mechanical pump w/ filter from OReillys, $35.99.

 

Yep new filters, already tried that, can fills up great, filter soaked, point hose down turn key fuel burst trickles out, put hose up by carb, turn key fuel burst trickles a little less. I know its not a water hose with 60psi, but I was expecting more and a more constant flow, seems to light to me, hook up to carb take off top of carb watch as key turns, less than half of bowl fills, carb was torn town this morning and everything cleaned and flowing. Just trying to see if fuel pump simply cant pump as it needs. When turning key and cranking, with current battery and booster set up, motor turns over and fired with starter fluid, but seems like not getting gas to take over and run. needle and seat and float all seem to be in working order, rebuilt the ac pump as the inner plug deal was ripped apart and the plunger gasket had a hole in it. Now all new there, A little aggravating I am on a shoe string budget. Was hoping to get it alive this weekend. But until I can figure out this fuel deal, I dead in the water. I know I have good flow from the tank, I pulled the inlet hose off the pump, and shoved it in my 5 gallon gas can, and it emptied the 5 gallons I had in about 5 mins with no help from me. took pump off truck, and made sure the inlet and outlet where clear and flowing, they where. Well thanks for the reply and hlep.

 

Fuel pressure is generally between 3 and 6 psi.

 

Is is that a constant flow or does it kind of pulsate and also if possible at what RPM?

 

A mechanic's vacuum gauge will test fuel pump output pressure. Should already have one of these for engine diagnostics and carburetor tuning. Simply connect the gauge to the fuel pump outlet and spin the engine over with the starter for a few seconds with the ignition disabled, or not. Most stock or stock-ish carburetors want to see no more than about 5 psi static pressure. Imported el-cheapo fuel pumps are notorious for excessive output pressure and other defects.

The fuel pump volume output is a different test. At least a pint in 30 seconds. High pressure is not a substitute for low volume. There aren't very many tests or adjustments on a carburetor, but every one is very important. Pressure, float height/fuel height, jetting, power valve, etc.

 

Thanks, I do not have vacuum gauge, I had determined the fuel pump was in fact bad. I bought a new one and installed it, Got plenty of fuel to start up and run. Then the water pump went out, waiting on UPS to bring my new one to install today hopefully. Thanks for the reply.

 

If I am seeing right you have a starter ground to the frame. Wrong.
A light wire from the alternator to the block will not do.
Place the battery ground on the proper lug on the engine.. Think of the starter return pat to the battery.
Heavy ground to engine. Scuff up and tighten.

 

Right, but this is the point of measuring, instead of assuming that since a part is brand new that it must be a good part - I did the same thing with my Y-block. I didn't test the new one for pressure output and it caused some real problems. It's a great way to cause flooding, or even start a fire. It only takes a minute to check. None of the carburetor settings (and there only a few) are very difficult, but every one is important.