Carter P4389 Doesn't Work when Connected to Carburetor

[taalpert71]

I am installing a new Carter P4389 electric fuel pump after an engine replacement on my Mercruiser 4.3L. The pump works fine as long as it is not connected to the carburetor. What could be the issue? Thanks!

 

[Scott06]

I am installing a new Carter P4389 electric fuel pump after an engine replacement on my Mercruiser 4.3L. The pump works fine as long as it is not connected to the carburetor. What could be the issue? Thanks!

Needle and seat in carb is stuck closed or pump is bad. Have you hooked up a pressure gauge to see if it makes pressure vs just pumping into a container ?

 

[Fun Times]

If you get fuel right up to the carburetor connection fitting, but the fuel isn't passing through the carburetor to fill the bowl then you possibly have either the carburetor fuel filter/strainer at the connection point plugged up or the needle and seat is stuck inside the carburetor and not allowing fuel to pass through to help start the engine.

What model carburetor and engine year do you have? Old engine serial number handy too for parts look up to help out with if needed?

 

[taalpert71]

1409 Carburetor 600 CFM AFB-style 4 Barrel Square Bore Electric Choke For Marine carburetor.

The old engine had a mechanical fuel pump. I got a new engine, but needs an electric fuel pump for it. The fuel isn't getting to the carburetor at all. S/N 0C765875

I'll need to put a pressure gauge on it. I'll check the needles first. Thanks!

 

[04fxdwgi25]

Connect a hose to output from pump and see how fast it pumps into a container. You either have a blockage leading to or in the carb or the pump is kaput. You have a solid 12 volt source to the pump?

 

[Scott Danforth]

first, welcome aboard.

second, make sure the pump is plumbed correctly. there is an arrow cast in the pump body for fuel flow direction.

third, make sure the pump is wired correctly with an oil pressure switch and a relay.

 

[Fun Times]

1409 Carburetor 600 CFM AFB-style 4 Barrel Square Bore Electric Choke For Marine carburetor.

The old engine had a mechanical fuel pump. I got a new engine, but needs an electric fuel pump for it. The fuel isn't getting to the carburetor at all. S/N 0C765875

Looks like you mostly have/had a 1990 engine year model with some upgrades.

Your newer model carburetor won't be in your parts guide though but as promised in case you need it, here would be your initial parts catalog that should fit a majority of the parts left on the engine.

1990 Stern Drive 4.3L [ALPHA] [443B100CS] - Parts Lookup | Crowley Marine

View parts diagrams and shop online for 443B100CS : 1990 Stern Drive 4.3L [ALPHA]. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.

www.crowleymarine.com

Weber Marine 4 Barrel Carburetor Troubleshooting

www.carburetor-parts.com

Mercarb Marine Mesh Fuel Filter for Carburetors 30D99

www.carburetor-parts.com

 

[taalpert71]

Connect a hose to output from pump and see how fast it pumps into a container. You either have a blockage leading to or in the carb or the pump is kaput. You have a solid 12 volt source to the pump?

Yes, connected directly to the battery with a relay. It fills up a gas can really fast not connected.

To answer the other questions above, I adjusted the needle valves as well with the same result. I did purchase a fuel pressure gauge to put in line, but won't see it till tomorrow.

 

[Scott06]

Yes, connected directly to the battery with a relay. It fills up a gas can really fast not connected.

To answer the other questions above, I adjusted the needle valves as well with the same result. I did purchase a fuel pressure gauge to put in line, but won't see it till tomorrow.

By needle valves do you mean needle and seat that is connected to floats , and have to take the carb top off to get a.


or needle valves as in the idle mix screws on base of carb stick up at a 45 deg angle ?

if you dump a little gas down carb bores does the engine start briefly? You want to figure out if gas is getting into the bowl or your idle passages are plugged.

Went through this with an eddy 1406 carb on my 65 pontiac this weekend. having a new engine built, took the carb set up I was running off the car to give to the engine builder… had the previous edlebrock 4 bbl sitting in a box for 3 years. Ran perfect when I took it off, emptied out the gas and put it in a box.… engine wouldn’t start unless I pumped the throttle to kick gas out of accelerator pump, would fire immediately then die.

had gas at the fuel line to the carb, gas in the bowl, idle passages were clogged. Took it apart soaked in carb cleaner blew all the passages out new gaskets fired right up and idled great…


what does the contents of your fuel filter look like ?

 

[04fxdwgi25]

That fuel pump should deliver 3 psi min and 8 psi max. The fuel gauge will tell you if the regulator / pressure switch in the pump is working correctly. Then it will all be on the carb and / or plumbing.

 

[Scott Danforth]

If the Carter pump moves fuel into a bucket, it will pump to the carb.

 

[taalpert71]

Well, as they say... never assume anything. Floats were WAY out of adjustment on the carb. Getting flow now. Thanks everyone for the responses.

 

[taalpert71]

That fuel pump should deliver 3 psi min and 8 psi max. The fuel gauge will tell you if the regulator / pressure switch in the pump is working correctly. Then it will all be on the carb and / or plumbing.

Yep, put a pressure gauge on there. About 7 psi. Floats were WAY out of adjustment. Got in there and fixed that and it fired right up. Thanks!

 

[Scott06]

Yep, put a pressure gauge on there. About 7 psi. Floats were WAY out of adjustment. Got in there and fixed that and it fired right up. Thanks!

Always the simple chit Just a matter of working through it