Hey Guys Questions before I start digging into the carb, here's what its doing and what I have done so far... When making a U-turn, or semi sharp right or left turn.... carb boggs.. cough's..sputters a little. Same when taking off from light if I happen to have to put on the brakes, carb loads up and car today actually died 3 times on my drive running errands... Then its a bitch to start and seems to be flooded. It has been doing this for a while, started out just a little annoying and minor symptoms but today it hit its peak and I have to fix it..:Smarty: A few weeks ago I cleaned the needle and seats, they looked just fine but I took out both and cleaned them. I also replaced the inline fuel filter. That did nothing to the symptoms, but at least I can check those 2 things off the list So....o No:.... is this a sticky float... too high a float level...o No: That's what I suspect as the issue, so that's the next action Questions: 1. Do I have to take off the bowl or can I adjust float by just taking out the screw on passenger side of carb bowl? 2.Haven't adjusted a float in... a long time, what should it be adjusted too? 2. If this doesnt solve issue, what would be next logical item to check? Thx VinMan out.....
pump to carb fuel pressure should be approx. 5.5 - 6.5 lbs ( per quick fuel tech ) , if more you may want to add a fuel pressure reg . bowls on : remove sight plugs and the fuel level should just let gas creep across threads . bowls off : flip em upside down and float should run about level with top of bowl . plastic floats are a little dif . the holley catalog lists measurements . either way dbl check with bowls on . I usually check the brass n plastic floats by first checking to see if any liquid inside ( none hopefully ) and then dipping in water and checking for bubbles . the black floats not so much - just replace em if suspect . idle screws , all in , out 1.5 full turns as a start up point shooter plungers should either be a flat plunger and lower ball or a plunger with lower taper and no ball . and check to be sure the gaskets are correct and the shooters sit down fully . that's a 4 corner idle carb so be sure the rear block has idle screws and also check , if possible , to make sure you have the correct metering blocks and base plate - both needed for the 4 corner . it's late , just got back from going out and having a coupe beers so this is off da cuff but its kinda basic quick check stuff for ya . there's a number of things to dbl check but it may be worthwhile to buy a correct decent kit for it and just go through it . get a holley book , check info , pics and tech etc and make sure the basic carb components are flat , square , true and passages are cleaned out . and check for vac leaks .
What model is it? You do need to set both of the float levels. You pull the site glass and fuel should be up to the bottom of site glass with engine running with mechanical pump. That sounds like a bunch of your trouble.
Guys.... with wife and kids (girls 7 & 9) making Crazy Loom rubber band bracelets... I was able to have some DAD time in the garage listening to the Warriors game and work on the carb.... Like riding a bike.... once I took off the air cleaner my "Holley tuning & diagnostic skills" ....found their way to the front of my brain....:Smarty: I removed the float bowl screw and no fuel leaked out. But when I barely "rocked" the car fuel came out... if my memory is correct, that's exactly what should happen and the float level is fine. When you remove the screw if fuel pours out then level is too high, but if you barely rock the car and some fuel comes out float level is fine and if you rock the car and no fuel comes out then float is low... right?.....o No: I also removed the needle again on front bowl to double check it was clean and not stuck... plus.... got a magnifying glass to look at the needle o-ring and the o-ring looks fine... I remember having a bad o-ring in a holley 20 years ago on my 327 el camino and replaced it which solved flooding issues I was having. Tomorrow I will check the fuel pressure, I have a FP gauge installed on the braided fuel line. I will make sure the FP is fine, it should be in the 5-6psi... 7psi max.... right? Thx VinMan out....
VinMan, just to clarify, you did your float level check while the engine was running, correct? If not, it's meaningless. I say this cause you were listening to the radio while working, so I asked the question.
It's an 850cfm and i think a 4150 model.... Tomorrow AM I will check FP and if fine will take it for a spin since I re-cleaned the needle & seat to see if its still flooding. If yes.... I will remove the bowls and inspect the floats. Thx VinMan out.......
850 DP is a list #4781 , on choke tower . if that is not on there just let us know what is . anytime you remove the needle/seat assy(s) the float level needs to be reset - they control the float level . I'm going out to shop in a sec to run furnace awhile - i'll grab holley book . edit : ( 2005 holley catalog n tech book - 9 variations listed , 4781 to 4781-8 ) needle/seat(s) - 6-504 primary jet - 80 secondary jet - 78 ( 4781 , 4781-1 and -2 use 80 ) front power valve - 65 , rear power valve - 65 primary and secondary shooters - .031 ( except 4781 uses .035 fr/.025 rr ) they listed some metering block numbers for certain variations but not others ? look for ( #34R11799AQ was a common front block # ) weird lookin part number , small and sometimes hidden in a blocked vac port etc . they coulda simplified that ALOT ! probably "top secret" carb recipe stuff . there are nice clear top numbers usually that probably mean something but I have not noticed any correlation with tech info . anyone got info on that ?
Just like deadman said, every time you pull the needle seat, the float level has to be set with engine running. You also have two floats, one in each bowl. Sounds like you are just checking one.
Guys... I forgot the float level could only be set with engine running.... ME = MORON.... So I adjusted both floats, front and back. Both seemed to be very high as fuel was running out of both, so i adjusted down until no fuel was coming out and up until I could see the level. So..... I think I'm OK. I took it for one quick ride around the block and hit the brake a couple times hard and no flooding. I will take it out for a longer drive between NFL games today.... stay tuned for final result Thanks again for all the help, Buick guys are the BEST VinMan out.....
Sounds like your floats might have been too high, and fuel was coming out of the vent tubes while stopping or turning as a result.
Another possibility if the floats are phenolic or nitrophyl (resin/synthetic) is that the E10 gasoline may be taking its toll and the floats aren't floating as well as they used to allowing higher fuel levels in the bowls over time. If this is the case, the adjustment may only be a temporary fix. Brass floats would be a good permanent solution if this is what's happening. Devon
Took it out for a longer ride... and.... seems to be fine. ... I even made such a sharp left turn I got a little sideways.....:laugh:... I did that to see how the carb would react to a sharp turn. I think its fixed guys. Being lucky were having spring for winter here in CA...sucks becasue were in a drought.... but good for car driving so I can drive it during the week when at home and since I work from home or hop on airplanes ... this week only one airplane day... to & from San Diego, so that means 4 days I'm at home. If no more replies from me here.... then all good to go! For now.... VinMan out.....
