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I am getting really frustrated with my 2150 flooding problems. I started with an apparent clog from fuel tank crud, replaced fuel pump and rebuilt carb. After adjustments, everything ran perfectly for a few days then I had a flooding condition so I suspected additional crud and pulled float & needle. Checked and adjusted float level, re-assembled and added an aftermarket filter before the carb. Another 100 or so miles and the problem is back. When I take the air horn off, the fuel level is accurate. Any suggestions as to why this is recurring and if there is another way to flood besides the sticking float?
I would suspect a blown power valve or a crack in the throttle body casting. Too much fuel is getting in your metering system. Were the jets good and tight? Is the problem an occasional thing with some sort of pattern or does the motor not even want to start?
In the past two days the problem has happened at the same point. In the morning, my first leg of my trip is 11 miles combined city & highway then the flooding begins. If I choose to stop then the gas weeps from under the carb and when the air filter is removed the vent gurgles fuel. If you drive through it it can 'heal' itself. The afternoon heat seems to agree with it but my analytical side says to not make too many correlations due to the number of things which have been changed. I've experienced no backfires and I have excellent acceleration so I discounted the power valve but the crack theory has me thinking. I would expect fuel to seep through a crack all the time but it may be tied to something else I can't see. I may pull it this evening just to see what I can see. The motor is flooded of course when this occurs but when it is working correctly then it starts within one revolution.
Well, I pulled the carb again and there is some moderate trash in the lowest part of the bowl. I pulled the power valve, jets, needle valve and seat and blew everything out. I did observe one anomaly. When dry-fitting the air horn, I noticed there was a raised boss on the air horn side that kept it from seating correctly onto the carb body. I know this has little to do with my particular problem but it goes to show how rebuilders can mix parts from one variation to the next. These obviously would never go together. A little dremmel action and they fit perfectly. Re-assembled the carb, reached in through the window and she started right up - no gas pedal needed (but I've been here before). We'll see how things go tomorrow.
Morning trip went well. Then I drove home and the same symptoms came back. I snatched the air horn off and the float level is ok but the direct vacuum vent tube which is right next to the air breather bolt hole is gurgling fuel which then runs down into the carb. I'm ready to replace the crazy thing.
It sounds to me like you keep pulling crud frum the fuel system (tank, lines, whatever) and it's getting stuck in the needle valve. You said you had crud in the fuel tank, then you found it in the bottom of the fuel bowl (bad!), and after cleaning it out the truck ran fine (for a while anyway). That's probably because you got the crud out of the needle valve, only until some more got back in there and you flooded out.
The fact that the fuel bowl vents gushed fuel is a sign that the fuel bowl is too full.
fmc400 - It's not the fuel bowl vent that gushes, it's the rear-most vent which goes from the carb baseplate straight up to the tiny hole right beside the air breather hold-down bolt. It's almost like the fuel is leaking down the base of the carb and trhe engine heat boils it up that tube.
battered_bronco - No, I haven't tried a phenolic spacer. There's no EGR but the heat must be a factor because of the way the problem presents itself. That may be a viable solution. And I can't say I know if there is a valley pan gasket because I didn't do the build.
Does anyone have a preference between Holleys and 2150s?
well i have been told that they run just fine without the tin but something about hot oil on the bottom of my intake compels me to replace it
in case you(or one of the masses) don't know what one is its the gasket never included in the "complete"(they just give you a cork to seal the ports off) gasket set, its a metal pan that covers the lifter valley and seperates from the bottom of the intake
ps(edit) are ya talking the 2bbl holley? and stock 2150 or the 2150 in general?
now the 2150 off a 82 5.0HO will graft nicely to these engines and improve it greatly granted its properly rebuilt
as will the hollet 2300 350(less cfm that the 2150 off a 82)-500cfm
but i don't care for holleys ingeneral they cost too much to tune and set-up if you chose to just saw a acc pump tuning set (for the 4bbl) listed for 105~107 from several sources(as i just checked) good news tho it also fits the 2bbl
either stock(ish) or carter/edelbrock
Last edited by battered_bronco; Aug 13, 2004 at 10:53 PM.
Man, when this thing floods I even get gas in the automatic choke housing! This carb has the heat riser tube from the exhaust manifold as well as the heater hose bracket that holds one of the heater hoses up against the choke housing. When the flooding occurred this morning I saw fuel dripping from the choke and when I pulled the choke housing and spring there was gas inside. I also pulled everything this weekend and inspected for cracks. The one area in question is (when viewed from the bottom) the casting that the pump discharge screw goes into. You can never tell if you're looking at a crack or an aluminum casting relief. After the flood job this morning I removed both heat sources and drove the rest of the way to work without incident. The saga continues. I am determined to beat this demon.
so is/was the choke working proper? not closing all the way/staying closed
have you tryed turning the choke cap a bit to let off the pressure / get it to open quicker
don't really know but something sounds rather screwed up got one truck the cap was about 45* too tight and said to my self probally out loud "what was he trying to do???"
Last edited by battered_bronco; Aug 16, 2004 at 08:40 AM.
No, the choke has always been adjusted completely open and right now I have the cover off trying to determine the source of the problem (yes, I know I have created a small vacuum leak by doing this). This whole "works great when cold, floods when hot" thing has got me loopy. Does anyone happen to know the exact path of the pipe from the choke through the carb? Is is just straight to the baseplate? I would like to understand the heat pipe airflow better. As I envision it, the sight vacuum causes the heat pipe to deliver exhaust into the choke assembly and then recirculate it via the carb baseplate. The heat expands the spring and opens the choke and canceles the fast idle cam. I'm just wondering if the heat is revealing a weakness with booster venturi or the power valve and maybe even the casting. The thing to remember is that I had the problem before rebuilding the carb but I thought the float was sticking open.
Fuel pump has been swapped also. I ran it home and back to work with the heat pipe removed and the heater hose NOT against the choke housing and had no problems. I will have to wait till tomorrow to know for sure. My poor daughter will have me drop her off a block from school if I have any more 1800 rpm idle drop-offs!
Well it did it again. The sad part here is the boss said we can't have an unreliable 2nd vehicle and the threat of selling it is eminent. I hate to get a reman'd unit to have it do the same thing.