Hi, I'm trying to reach out to see if someone is willing help with my situation or has experienced my same situation. A little back ground information, I purchased the Stromberg Big 97s Tri-Power setup new for my SBC that's in my 32 Ford Roadster. It appears the carbs are over loading with fuel. I have the recommended fuel pressure regulator by Holley (1-4 psi) # 12-804 to sustain 2.5 lbs psi recommended by Stromberg instructions. At first, the regulator was not set at 2.5 lbs of pressure but higher and flooded out the carbs and plugs. I made the regulator adjustment to 2.5 lbs and the engine would start and idle only. Any advancement with the throttle, the engine would stall out. Also, it appears that small amount of fuel is still seeping in the carbs after it has stalled and stopped. I have fuel supply line but no return line to the fuel tank? I had four barrel previously setup and had no issues, but I wanted to change to the Stromberg Tri-Power setup for nostalgia look for my car. Any help would be greatly appreciated. Mel Noes
sounds like floats too high, and the reg.??? maybe not working on that low of pressure...you're gonna need volume at low pressure to feed the 3 carbs..
I am assuming they are set up progressive and you are only opening the Primary center carb trying to get it running? Can you see which one is overflowing into the carb throat? All of them or just one? If you haven't already, verify the float adjustment on all 3 carbs. Lower the fuel pressure regulator to 2psi or even less to see if it stops overrunning the needle and seat. Do you have electric fuel pump or mechanical?
After you verify that the floats are adjusted correctly, fuel pressure is correct, and that the needles aren't sticking open, disconnect the linkage and adjust the primary carb by itself (assuming you're using a progressive linkage setup). Get it running/driving off the center carb first and extrapolate the mixture screw settings to the other two carbs as a baseline (for example 1 1/4-turns out). Then, sync all three carbs using a Uni-syn and reinstall linkage without changing your previous settings. Report back. Keep in mind those 3 Big 97s are putting out 750 cfms, likely too much for a mild 350 or smaller.
First post for original poster who hasn’t been back since he posted his question a week ago, so let’s hope that he makes it back soon……
Hi, yes I'm using the progressive linkage and trying to get it running. I have a mechanical fuel pump and utilizing the Holley regulator. I'm not sure if it's over flowing in the secondary carbs. But, I know for sure the primary is overflowing. I'm going to check my inlet valves and see if I have anything keeping the balls from seating properly. Then I will check the floats level and lower the pressure regulator to 2 lbs. I really appreciate the responses and advice guys. Thank you. Also, I apologize for not responded back sooner. It's been very busy for us and trying to find the time to get back to my car. I will post my results and hopefully it helps out other people.
That particular holley regulator is supposed to have no more than 7lbs pressure running into them. Some run return lines with that regulator to help reduce the high fuel pressure. Years ago, about half of the comments on here suggest that they work, and the other half had negative comments. A replacement sbc fuel pump may put out considerably more pressure. Just something to keep in mind. It has been said many times, block off the secondary carbs and set it up on primary carb initially to get it running. Then add in the secondary carbs. I am using larger original holley type ‘94’s with similar problems. Leaking power valves and incorrect float levels don’t help!
An update, I checked my inlet valves and floats everything appears to be fine. I'm looking at replacing my Holley regulator. I had someone recommend a Malpassi fuel pressure regulator over the Holley product? Clem, I'm considering running a return line as well. However, I'm not sure what make and model I have for my fuel pump. I know it's chrome and appears to be a Holley. I tried locating a model number or some kind of identification numbers but nothing on it. Any suggestions on a return line?
far superior choice going with the Malpassi according to those that have used them, and they look more traditional.
After discussing this on here, a couple suggested running it to a tee before the fuel pump, so that is all I did as the car was almost finished. Seems to work just fine. Here’s the thread from way back https://www.jalopyjournal.com/forum/threads/a-couple-of-questions-sbc-fuel-pressure-problems.860941/ or run it back to the tank, as it should be.
The Jalopy Journal
