View Full Version : Needle & Seat
Scooterz
05-24-2010, 03:57 PM
Here is my brilliant luck: I installed a new fuel pump & lines regulator, etc... I go to start the car for the first time & hit the FP toggle, it fires up & dies in about 10 seconds. I shut off the pump. I hear "trickling"... like a dripping sound. Not sure, I pull the air cleaner, pull the front bowl off & inspect the PV... it was fine. Then I hit the toggle again w/ the air cleaner off & watch the carb (950 QF) & I see fuel PUKING out of the front vent/tube on the primaries. I had dumped a TON of fuel down that poor carb!! Pulled the needle & seat, it looked fine, it was sealing & moving like it should. Put it back in the carb & the problem went away. Apparently it was stuck & that is where the fuel goes when it is stuck. (It is a BP system).
Is this just a fluke??? Maybe it sat too long w/o being ran? Had it a 7PSI at the time. Should I replace it (needle & seat) even though this carb is fairly new?? Probably need a new oil change now... there is 100.00 bucks gone in a flash. Scoot
TheRabbit
05-24-2010, 05:50 PM
It more than likely was a piece of trash or just seized. All kinds of small pieces of trash including foam from the fuel tank end up in the carb. You may want to clean the tank and flush all the lines real good to make sure nothing else in it.
markdunlap
05-24-2010, 06:51 PM
Besides a 100 mesh stainless element filter before the electric pump to protect it, I run a filter after the pump with a finer paper element to protect the carb.
If you look at Aeromotive tech section it shows they recomend that too.
cepx111
05-24-2010, 10:34 PM
What? A stuck needle & seat on a Holley?? :shock:
Well blow me down.....I aint never seen that before! lol :lol:
I suspect a tiny peice of rubber from one of the hoses or some other peice of thrash got hung in there and when u took the needle & seat off, it fell out, it happens.
Anytime you work on the fuel system be ready for something like that, I always have a helper looking at the carb when I first prime it up, just a expensive learning curve Rigsby.
I too run a pre-filter and a post filter.
Cp
Tod74
05-24-2010, 10:41 PM
If you ran the SS Braided hose then you should have(if you didn't) ran a few gallons of fuel through the line with it unhooked from the carb or regulator to wash out any shavings from cutting the hose. JMO
JEFF69Z28
05-25-2010, 06:47 AM
If you ran the SS Braided hose then you should have(if you didn't) ran a few gallons of fuel through the line with it unhooked from the carb or regulator to wash out any shavings from cutting the hose. JMO
X2
TheRabbit
05-25-2010, 08:42 AM
FYI. I spent some time talking to a MagnaFuel rep at the PRI show. He said they don't recommend putting a filter before the pump. It causes the pump to work way harder than it was intended. Makes it draw too many amps especially if it gets clogged up. Makes sense, but I still have a BG filter attatched to mine. I just don't like the thought of no filter before the pump. These pumps are made to push fuel not pull it through any kind of resistance.
Scooterz
05-25-2010, 10:55 AM
I hate being a newby sometimes.... these are expensive mistakes!!! I thought I did a pretty good job too. I used all A/N, All SS hose, used a painless wiring/relay kit, etc... only to have a quart of fuel PUKE down into the pan as my end result. I could open a "AN fitting store" at this point...
Wabbit: I have a new Mallory fuel filter very close to the tank. I managed to do it all gravity fed to the pump. I installed one filter is all. I thought about a second, (I do have a 8AN inline filter @ home), but I thought it would be too excessive. It is a return line system too. I hope it all woks out (I still have not driven the car w/ the new fuel system.
The other thing I noticed is that the insulator pad for the pump is not enough to keep it as quiet in my opinion. It cannot be heard when the car fires up though.
markdunlap
05-25-2010, 06:09 PM
When doing the initial pressure test on the fuel system, like said above, run some fuel thru all the line up to the carb to a catch can. If it is a Holley with sight level screws, remove them before pressurizing the carb. If the needle and seats are misadjusted too high or get stuck, the fuel will usually all come out the sight plug holes without going up and over the vent tubes and into the carb and engine. If there are no sight level plugs, put hose over the vent tubes and route away from the carb to a catch can.
cepx111
05-25-2010, 10:56 PM
. If the needle and seats are misadjusted too high or get stuck, the fuel will usually all come out the sight plug holes without going up and over the vent tubes and into the carb and engine. If there are no sight level plugs, put hose over the vent tubes and route away from the carb to a catch can.
Thats a pretty good idea right there ^
Cp
TheRabbit
05-26-2010, 04:18 AM
. If the needle and seats are misadjusted too high or get stuck, the fuel will usually all come out the sight plug holes without going up and over the vent tubes and into the carb and engine. If there are no sight level plugs, put hose over the vent tubes and route away from the carb to a catch can.
Thats a pretty good idea right there ^
Cp
Hell that takes all the fun outta turning the pump on, running around to watch and see if it's ok or spilling into the motor then running back to shut the pump off, then having to drain the oil because you filled the motor full of fuel!! Been there done that several times! :oops:
Sometimes it's just easier to sit back and think for 2 minutes about what you're doing before you start.
Good simple idea.
Scooterz
05-26-2010, 02:27 PM
No doubt. It is funny how we get caught up on a project & do not take the time to think about these simple things!!! That cost me 88.00 just by flicking the pump on one time. I appreciate all your feedback. I like what Tod said too... just got too excited & did not think carefully.
racecrafter
06-28-2010, 07:21 AM
If you are going to the track by yourself why not put a momentary switch for the fuel pump on the fire wall that way you can prime the carb while looking at the carb.
TheRabbit
06-28-2010, 10:52 AM
No doubt. It is funny how we get caught up on a project & do not take the time to think about these simple things!!! That cost me 88.00 just by flicking the pump on one time. I appreciate all your feedback. I like what Tod said too... just got too excited & did not think carefully.
just got too excited & did not think carefully
That may apply to me in more than just racing stuff. :shock:
Scooterz
06-29-2010, 02:18 PM
If you are going to the track by yourself why not put a momentary switch for the fuel pump on the fire wall that way you can prime the carb while looking at the carb.
Good idea, nice & simple. I did fix it & it holds now. There was some very small rubber debris in there.
Wabbit: me too brutha. Man that girl did some crazy stuff... more high maintenance than my car too. LOL!!!!