serious holley carb issue
06-28-11, 09:27 AM
#1
serious holley carb issue
I know carbs somewhat but I'm no master, and this carb is kicking my ***. I bought the car and it already has a Holley 390 on it. The 12a thats in it is street ported. Its running extremely sluggish, and if i just straight up stomp the gas it cuts out to the point it will shut off if i dont let up. Ive checked the float levels and re adjusted them to the bottom of the sight hole, and adjusted the idle to where its smooth (well smoother anyway). Its also running ridiculously rich. Like I said Im no carb master. I also wonder if this is even a god carb for that motor
06-28-11, 10:05 AM
#2
the holley is known for running rich. i only know of 3 holleys that have been prepped to be used on a rotary: 465, 600, and 650cfm which can be gotten from RB and probably mazdatrix as well. urs being a 390 leads me to believe its just an off the shelf holley which could explain why ur having so much trouble. ur going to have to get some smaller jets to lean it out some before u get it to work half way decent. not sure why but RB does away with the power valve. maybe someone here can give u some jet numbers to start with.
add a spacer or make one.
06-28-11, 11:49 AM
#5
I honestly dont know if its RB or not it was already on there when i bought it and i havent looked the manifold over enough to see if its got any labels. well heres what we finally did. Im sure im not saying this right but we ended up taking the linkage out of the 4 barrel and Im just running the primary side right now till I can afford a RB holley streetport ready carb. Its running reallllllly smooth now and the cut is gone. Im changing plugs tonight and going to try to time it better for the streetport. Judging by the carb work Im sure the timing is off as well. Its still kinda slow for having a streetport but Im hoping its the old *** plugs and not the fact that we disabled the 4 barrel
06-28-11, 12:38 PM
#7
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You need to swap out the accelerator pump jet. When you stomp on the gas does it try to flood or just sputter?
Are you running an upgraded pump with a pressure regulator?
Are you running an upgraded pump with a pressure regulator?
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06-28-11, 12:45 PM
#9
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Make sure the pressure is set to 6 psi.
I'm betting you are most likely leaning out unless the car smokes bad when you floor it. The accelerator pump jet is the one sits between the two primary bowls on the top. Check and see if fuel squirts out of it when you press the gas.
I'm betting you are most likely leaning out unless the car smokes bad when you floor it. The accelerator pump jet is the one sits between the two primary bowls on the top. Check and see if fuel squirts out of it when you press the gas.
06-28-11, 12:53 PM
#10
ya my pressure is sitting right on 6 psi. and it blows out blueish smoke when i floor it. The fuel is squirting nicely and consistently. but on the secondary side ( i guess thats what its called )
its kind of just blowing out. once we removed the linkage for the secondarys the sputtering quit. so the problem obviously lies with them.
its kind of just blowing out. once we removed the linkage for the secondarys the sputtering quit. so the problem obviously lies with them.
06-28-11, 01:08 PM
#13
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This should be what you have:
http://www.holley.com/0-8007.asp
This will help you a ton: http://www.holley.com/data/Products/...8108-2rev1.pdf
http://www.holley.com/0-8007.asp
This will help you a ton: http://www.holley.com/data/Products/...8108-2rev1.pdf
06-28-11, 01:42 PM
#17
Make sure the pressure is set to 6 psi.
I'm betting you are most likely leaning out unless the car smokes bad when you floor it. The accelerator pump jet is the one sits between the two primary bowls on the top. Check and see if fuel squirts out of it when you press the gas.
I'm betting you are most likely leaning out unless the car smokes bad when you floor it. The accelerator pump jet is the one sits between the two primary bowls on the top. Check and see if fuel squirts out of it when you press the gas.
06-28-11, 02:04 PM
#18
Stock manifold. Carb adaptor/spacer. Someone removed the choke parts on the side. They added OMP hoses in the choke holes. Also added a screw so the secondaries are mechanical right now. Strange pulling the throttle from the opposite side with a throttle kit (I have one too, refering to the blue bracket thing, mine is chrome and I couldn't use it).
Your issues are beyond me as I barely know the holley myself. At least the venturis look smallish like a 390, like mine.
Your issues are beyond me as I barely know the holley myself. At least the venturis look smallish like a 390, like mine.
06-28-11, 02:04 PM
#19
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Are you premixing? it look like that clear plastic line is coming from the OMP and is supposed to go to the hose in the choke hole. I don't see any of the OMP linkage.
That copper bung by the adjustment screw should be hooked to the distributer, it's a vacuum port.
It does look like a vacuum secondary carb that has the vacuum diaphragm pulled. I can't see any linkage to the secondary at all. It looks like someone took an old vacuum secondary carb and tried to turn it into a race carb by pulling the choke and vacuum diaphragm.
That copper bung by the adjustment screw should be hooked to the distributer, it's a vacuum port.
It does look like a vacuum secondary carb that has the vacuum diaphragm pulled. I can't see any linkage to the secondary at all. It looks like someone took an old vacuum secondary carb and tried to turn it into a race carb by pulling the choke and vacuum diaphragm.
06-28-11, 02:08 PM
#20
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I didn't see that till you said something, lol.
I'm guessing that you probably have a vacuum leak where the secondary diaphragm was removed as well. If it was me, I'd remove that screw and install a new vacuum diaphragm.
I'm guessing that you probably have a vacuum leak where the secondary diaphragm was removed as well. If it was me, I'd remove that screw and install a new vacuum diaphragm.
06-28-11, 02:15 PM
#21
no im not premixing I just disconnected them to get the lid off the carb for the pics. Good God Jeff you blew my mind with all that... Im thinking I should say the hell with that mess and get a sterling carb if I still can. But his website says theyve stopped until further notice...
Last edited by FCinWV; 06-28-11 at 02:24 PM.
06-28-11, 02:27 PM
#24
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I really liked my RB holey carb setup but that carb is just a mess. I would take some carb cleaner and spray the outside of the carb while the car is running. If the car bogs, you know you have a vacuum leak.