Dauntless Starving For Fuel

I have a a 225 v6 Rochester 2g and a check valve so the fuel does not drain back. My problem is when I start it, runs fine for a sold 25 second then gradually stalls out. Then it’s extremely hard to start then slowly starts. It seems to get better when it gets hot. It will intermittently just cut out and not start for 25-30 seconds. Then it seems to run fine. My guess is the fuel pump??? It’s only 3 years old. I checked the fuel filter and check both are clear. Any suggestions????

 

have you checked the ignition system

 

I have not I have and HEI possibly a coil, but wouldn’t the coil be bad or good not work intermittently

 

The question is---fuel pump, carburetor, ignition or ? Intermittent problems are trouble for sure, but it does sound like your trouble has a pattern. I would try to affect that pattern to narrow the search for solution.

One troubleshooting thing I would try [with all points of safety in mind] is to get a spray bottle of gas, start 'er up and be ready at the the carb. with spurts/a mist of gas to the carb. If it continues to run as desired with the supplemental gas you've eliminated the ignition and you can move on. I'm suspicious that it may be the carburetor and a thorough cleaning, inspection & carb kit is the need, but totally a guess!

 

Such a problem is indeed gas or spark. If I suspected a fuel problem, I would do two things. First, I would do a volume and pressure test on the fuel pump. I would next run the engine until it stalled, and pull the top off of the carburetor. If the problem was gas, I'd expect the float bowl to be empty.

 

The carburator was professionally rebuilt about 3 months ago with “ethanol friendly parts” and it did run great. I also did order a clear fuel filter and an pressure gauge. You are correct the best way would be to test the fuel pump. I have to find a kit that the gauge goes Low enough, most are higher psi for the FI applications.

 

Look at vacuum testers. Most also contain a fuel pump pressure tester.
https://www.amazon.com/Carburetor-Valve-Pressure-Vacuum-Tester/dp/B00KRJFSFQ/

Though there's no spec, you can do a volume test easily. Disconnect the ignition and direct the fuel pump output into a jelly jar or such. Crank the engine and you should see a healthy spurt that will fill the jar in say 30 seconds of cranking. A weak fuel pump should be obviously weak.

Obvious caution, but be careful not to start a fire or run yourself over if the engine starts.

 

So I pulled the fuel pump last night and hooked up my hand pump I use to bleed brakes. This pump has the port for the return line. I plugged the 2 lines in the inlet side of the pump and hooked the guage up to the out let side that goes to the carburetor. It will not hold vacuum I’m assuming the diaphragm is bad in the pump, do this make sense ?

 

I had this issue with a "new" fuel pump. The ethanol ate the diaphragm. I replaced it with another one and solved my issue. I also had a problem with the ignition control module in the HEI that was an intermittent problem as you describe. It gave spark, but not great. I replaced that with heat sink paste and it also solved that other separate problem as well.