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Old 11-25-2010, 09:23 AM
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fuel flow problem

68 camaro with big block, carter electric racing fuel pump. when I connect my fuel line to the carb fuel quits flowing when i disconnect the fuel line from the carb fuel flows again. I have an in line glass filter so I can see the fuel inline. the system has worked great till recently and only changes is a new holley 850. anyway any suggestions would be appreciated o and yes the filter is not clogged. it will not even fill the glass u when connected.

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Old 11-25-2010, 09:30 AM
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It has to be in the carb, either the inlet is plugged or the float is stuck maybe? Are you using a bypass regulator? If so, what pressure is it set at?
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Old 11-25-2010, 09:39 AM
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fuel flow

Thanks for getting back so quick. it is set at 5lbs but when I disconect the line from the carb the filter fills and fuel shoots out the gas line but when I connect the fuel line back to the carb the filter doesnt even fill which is approx 8" before the carb and that is what thows me off the fuel doesnt make it to the carb. by the way 850 double pumper mechanincal secondaries it didnt do this at first about 1 week after replacing the carb. but I am thinking just coincidence it started after replacing carb. anyway any ideas greatly appreciated.
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Old 11-25-2010, 10:03 AM
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Any chance the inline filter is on backwards? I think most of them are directional.
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Old 11-25-2010, 10:05 AM
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Quote:
Originally Posted by 68NovaSS
Any chance the inline filter is on backwards? I think most of them are directional.
Seen this before also.



Cole
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Old 11-25-2010, 10:14 AM
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fuel flow

No and I didnt even have to mess with that when I changed the carb and it is a new filter but I did check it to make sure it is not clogged and yes it is marked in and out. it just really throws me off, it flows when i disconnect the 3/8 line from the carb and I know it is no longer pressurized when i do that but it is aggrevating it has worked perfect no problems for months till I changed the carb and I only drive this car three or four times a month I am just wondering could the fuel pump be bad. it sounds strong and I know you cant go by that but I am just throwing darts hate to buy another fuel pump and it do the same thing.
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Old 11-25-2010, 10:34 AM
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Just from reading your description it sounds like the blockage has to be in the carb itself. Is there an adapter fitting for the fuel line at the carb? Does the carb have an internal screen or filter at the fuel inlet? With the line connected does the fuel pump sound as if it is fighting against pressure (slightly deeper tone) or spinning freely? If you block the fuel line outlet (with your thumb!!) when its disconnected does it pressurize? Better yet put a gauge on the end of the line and see if it builds pressure!
Good luck,
Alan

PS I just went back and read your first post. You didn't say how this situation is effecting the performance. Is the car still running? Seems to me as I remember from my carb days the fuel filter is never totally full, anyway. There was always air there.
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Old 11-25-2010, 10:45 AM
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fuel flow

no screens or filter in the carb no adapters. I havent tried to block line off when disconnected from the carb I will try that and see. I dont understand why the filter want even fill up when line connected to the carb that seems to tell me that fuel is not even making it to the filter much less the carb.
O and your right the filter never filled all the way up prob 3/4 but now barely anything. when i first put it on no problems drove it easy and very little than took it out got on it pretty hard no problems then as i let off the acclerator I noticed it seemed to act as if ran out of fuel than picked back up I got on it again no problems so when i got back to the shop just ideling checking things out it died and sounded as if it of fuel snd filter was dry and that leads up to where i am now and by the way yes I have fuel in tank done checked that and even added some to make sure.

Last edited by pacman; 11-25-2010 at 10:52 AM.
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Old 11-25-2010, 11:09 AM
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How old is the fuel pump, Could be the pump is internally blocked or just a weak pump, Simply going bad on you if it worked before that is and it was working before you changed the carb correct. JMO


Cole
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Old 11-25-2010, 12:24 PM
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Bypass the regulator then test it.
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Old 11-25-2010, 08:38 PM
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fuel flow

I really appreciate ever ones feed back I took off regulator and pressure gauge now I am not even getting fuel with the line off the carb so I think Cole is right the fuel pump has just went bad the pump is about 1 year old but is not driven that much but don't see how it can be anything else I guess just coincidence it happened at the time i swapped carbs. any way I will get a new one this weekend and let everyone know how it goes and once again Thanks to everyone for their time and help. Sure is great to have access to knowledge like this. Thank you!
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Old 12-03-2010, 01:32 PM
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fuel flow

just wanted to let everyone know I pulled the pump to replace it and found a small piece of rubber looked like gas line was blocking screen on inlet side of fuel pump. so i replaced my gas line to the pump with fuel injection line since it is lined maybe to stop that from happening again. gas line was not that old and was pretty short maybe 12" just from tank to pump I have never seen that on fresh line before. anyway once again wanted to think everyone for their time.
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Old 12-03-2010, 06:29 PM
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Glad you found the problem.



Cole
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