6pack carbs - looking for advice

[70RTdroptop]

Before I put my Challenger away for storage, I was starting to have some carb problems - running real rich and rough because too much gas was dumping into the front , center, or rear  carb. Couple of times the center carb was fine, but the outboards ( one or the other ) were dumping gas in. This is at idle, sitting in the garage, keep in mind. Now, what I did, based on advice from some members here, was to shut down the engine, remove the needle and seat, clean it out, and re-install. I'd re-start the engine and it would run just fine ( at least until the next time, when it'd be a different carb acting up ). What do you think is causing this?  Crap floating in the gas, poor fuel filter, o-rings on the needle / seat assembly going bad? I'm concerned because I don't want all that extra gas washing down into the oil pan. I've already changed the oil after the first time I had all that excess gas going in, and I don't need to make a habit of changing the oil every 2 or 3 times I drive the car. Plus, this is all on a fresh balanced and blueprinted rebuild, and I don't want to take any chances on possibly messing up the engine. All carbs were rebuilt about spring 2005, and right now I've got the stock-style fuel filter. Any advice on what to do would be very welcome!

[MEK-Dangerfield]

Can I ask what fuel pump you are using? If it's something after-market, it might be a little too strong for you. I have a Carter Hi-volume pump that is supposed to put out 6 PSI, but I get about 10-11 at start-up, and 8 after it has run a while. I put a fuel pressure regulator on just to play it safe.


  Mike

[Oldschool]

Can I ask what fuel pump you are using? If it's something after-market, it might be a little too strong for you. I have a Carter Hi-volume pump that is supposed to put out 6 PSI, but I get about 10-11 at start-up, and 8 after it has run a while. I put a fuel pressure regulator on just to play it safe.


  Mike

    (hard to believe that I agree with MEK    )  I was gonna post the same question when he posted it first.....         

[MEK-Dangerfield]

Great minds think alike? 


  Mike     

[70RTdroptop]

Knew I was forgetting to include something! Looks like I've got a hemi fuel pump in it. Think that's putting out to much pressure? I'm kinda leaning away from that idea, though, just because this carb problem has only surfaced lately, and the fuel pump's been in the car for a couple years already. Still, I'll switch out to the hi-performance 440 fuel pump if that hemi fuel pump might be the trouble. What ya'll think?

[Chryco Psycho]

for the cost of a new saet of needle & seat asssy I would replace them , & replace the filter & check the pressure of the pump , the Hemi pump sghould be fine Unless it is a HP pump with 11-12 PSI if so you copuld replace it with a 6 PSI pump or use a regulator in between

[Moparal]

Have you tried pulling one bolt out of each outboard carb and catching some fuel in a clear gas to see if you have contaminants? When the carbs were rebuilt, did they use an nos kit or a kit with the teflon coated needle and seat for unleaded gas? Did you take some B12 and spray down the air bleeds to clean them out? They will get very small particles built up in the bleeds and relase once in a while or all at once.  Also, depending on vacuum, the outboard metering block gaskets could be getting loose from age and letting the fuel seep. It will cause a bleed down affect. I am not an expert at doing anything, these are problems I have experienced and fixed first hand myself. Remember gravity flows down.  Sorry if this doesn't help or if you have tried any of this. And untill you figure out the problem, I would suggest emptying the fuel bowls front and rear when not in use for long periods, so you don't keep washing down the cylinders and contaminating your oil.  Good luck with your problem. Make sure the linkage is closing the throttle shafts all the way down too. Six packs are never maintenance free.

[moper]

What is the condition of the tank and lines? Especially in many older restorations, the tanks were either reused, or replaced with aftermarket ones. After some years, the aftermarket can develop rust just like the originals do. Check the fuel from the pump's output..Before the filter. Also, run a metal cannister type filter for the best filterring. It sounds more like a fuel system issue than a carb or delivery issue. You're right to worry. running a new engine very rich will ruin the rings very quickly.

[70RTdroptop]

I actually had a buddy of mine rebuild the carbs, so I don't know if he used an nos kit or one of the newer replacement kits. For now I'm gonna do as Chryco suggests. Needle / seat assemblies are pretty reasonable, so I'll replace those, and get one of those 40-micron or so fuel filters. Then I'll follow up with checking the pressure being put out by the pump. Sure is strange the way everything ran so good for a long time, then suddenly in a space of a couple weeks I get these problems happening. And of course now that we're stuck in a deep freeze in WI here, it's gonna be real fun trying to get these things worked out. Well, I'll just keep plugging along on this. Worse comes to worse, I'll get some nos carb rebuild kits and replace all the gaskets, o-rings, etc. Got all winter to do it, after all Thanks for all the responses! Keep 'em coming!