Problems carb or fuel pump

VINCENT RUDI · #1 (**permalink**) 03-09-2009, 05:40 PM

I drove my cobra this weekend for about 20 min and spun some rubber around the development, when i pulled in the driveway i notices a little miss, a little miss turned into the engine not ideling right. I seen some black pepper size particals in the filter between the carb and pump. I checked the canester filter at the gas tank and thare was no sign of anything, the filter is like 5 or 10 micron. I have a mechanical summit fuel pump by the way. I am thinking that from me geting on the pedel to hard i beat up some thing in the pump, maybe thats whare all the particals came from. And now maybe the carb is clogged. I have one of those spectra glass filters whare you can see the fuel. It dosen't look like it is flowing consistantly should it be full at all times. Anyway it will not idel but it will run if i stay on the pedel. I also smell a lot of fuel. What procedures sould i take now. Help!!!

Night Enforcer · #2 (**permalink**) 03-09-2009, 06:09 PM

Even if your fuel filters are dirty after you change them, you need to check your fuel pressure. Do you have a fuel pressure gauge? If not you will need to get one to see if your pump is putting out the correct pressure. What type of carb are you running? If it is a Holley they are are very sensitive to both low and high fuel pressures. Most Holleys need between 5 and 7 lbs of pressure to operate correctly. More or less and they will lean out or run rich.

Tim Brewer · #3 (**permalink**) 03-09-2009, 06:54 PM

It doesn't matter how hard you ever get on it, the pump doesn't know the difference, it just pumps...

Bobcat · #4 (**permalink**) 03-09-2009, 07:40 PM

You didn`t say whether it was a Holley or not , but if trash gets under the float needle valve , it can cause what you are experiencing . If you saw trash in the filter , probably that`s what under the needle seat . I`ve had that happen several times . Remove the needle valve(s) , clean it/them , reset your float levels and you should be ok .
One thing that bothers me is that you said you had a glass filter ?? I don`t know any racing organization that will allow one of those because of the potential for breakage and then fire .

VINCENT RUDI · #5 (**permalink**) 03-10-2009, 07:01 PM

I have a edelbrock proformer 750 carb , and i will be changing that filter, i was thinking the same thing when i installed it, didn't like it one bit.

cobred · #6 (**permalink**) 03-10-2009, 08:28 PM

I would start by taking out the fuel level plugs in the side of the carb. with the engine running. If fuel runs out you may have some crap in the needle and seat. Then just pull it out and clean it and reinstall and reset the float level.