SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: 75 fantasy on August 09, 2013, 08:05:31 AM
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I'm at the end of my rope with my carb related issue on my fj40. It seems like it is starving for fuel under light acceleration. I've tried to adjust everything (timing, no vac leaks,etc.)but would like to try changing accelerator pump nozzles. I don't mind ordering some but I'd like to get figured out this weekend. Do any Ventura area Scjb members have pump nozzles for sale or use for testing? I need to try a 31 or 37.
Thanks
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bump for the venturans
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I'm not anywhere near Ventura this weekend but I'll try to help.
What is the set up in your FJ?
What carb are you running?
Most of the accelerator pump cams have multiple settings, have you tried adjusting that first?
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I'm not anywhere near Ventura this weekend but I'll try to help.
What is the set up in your FJ?
What carb are you running?
Most of the accelerator pump cams have multiple settings, have you tried adjusting that first?
Thanks crew chief
I did try the adjusting the cam but no luck.
It has a sbc, th350, stock t-case, 4.11 ratio, sounds like a cam but not sure size, 525 demon vac 2nds.
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OK, now I have a few more questions...
What are the symptoms? Stumble?
Is this a new symptom?
Is this a new set up? What's changed?
What ignition system do you have? Have you checked the mechanical and vacuum advance functions?
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Symptom - under normal acceleration 0-15 ok then a slight stumble, hesitation then it clears up. At cruising speed (45) step on it same symptom then clears up.
New setup. Had the motor for awhile, new carb(CL) friend sold carb before I bought the boat. He was parting it out.
Bought a boat for the motor from a friend. He said PO just had it rebuilt but friend doesn't have specs. Said it was fast(I know everyone says that) but on it working I trust him. Our moms worked together for years.) I changed the pan and noticed the caps were numbered, fresh honing marks, windage tray.
Running an HEI w/vac advance. Vac advance works.
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Raised in oxnard so I think u have a bad carb how much vaccum do u have I just changed from a 750 dp to a 650 till I get a new one I found a crack in the main body so no beno put a friend race boat carb on no problems runs a lot better.
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hey im out on the east end i could give you a hand. i am working nights . be up monday morn around ten or eleven, after that i am back on day shift so whenever .. give me a call 816-3582 ... robbie
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Raised in oxnard so I think u have a bad carb how much vaccum do u have I just changed from a 750 dp to a 650 till I get a new one I found a crack in the main body so no beno put a friend race boat carb on no problems runs a lot better.
Chad
My full manifold vac is 15. I think because of the cam.
Robbie
Cool ill let you know.
Thanks guys
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Well I tried a 37 and 31 nozzle. Didn't notice a difference with the 37 but may a little worse with the 31. Back to the drawing board. :banghead: