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Old 10-23-2002, 02:56 PM
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Post Fuel / Carb problem

Today I stumbled upon a user with the exact problem I have and is why I joined to help find a answer, I also joined just to be of any help to others. My problem is. 6 months ago, I rebuilt the SBC 350 that i installed in my 86 olds cutlass, at Idle, fuel drips out of the carbs boosters, I`ve tried 5 different carbs, 2 holley`s and 3 Quadrajets, the Q-jet I`m running now is remanned. During the rebuild, It was a basic rebuild, i only replaced the bearings and rings, the only thing I changed was the cam, I was running a summit cam, now I have a comp cams HE 268, 450 lift and 218 duration. the summit cam was 214/224 duration, 442/465 lift. the comp cams shaft has a incorrectly ground fuel pump lobe, fuel pressure was 14 psi, so I converted to a carter electric 5 psi pump, the problem persisted, no matter what carb i use, fuel still drips out of the boosters at idle, I`ve spent hundreds of dollars and 5 months on this problem, and have not put a 100 miles on my car because of it. comp cams swears there cam is not at fault, but I didn`t have this problem until I used there cam. the only thing i`ve found that will get rid of the problem with any carb i use is adjusting the idle screws, rich or lean, either way, the drip stops, shut the car off and start it again, the drip returns. sometimes only the left booster does so, other times both boosters. I`ve talked to many people, rebuilt every carb, bought new parts, did everything I know to do and the problem will not go away, anyone who has any clue how to solve this problem, please let me know, I can`t afford to spend anymore money on fuel system peices when i`ve run out of things to replace. it seems to me the cam is at fault, but I`m not positive, all I know is it didn`t start dripping until I did the rebuild and used a different cam, anybody have any other clues? please let me know before it drives me insane. thanks a million.

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Old 10-23-2002, 05:26 PM
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Fuel dripping is usually only one or two things . If you've checked the float height, which I imagine you have, you might try fuel pressure. I have never seen a cam cause such a problem.

[ October 24, 2002: Message edited by: woodz428 ]

[ October 24, 2002: Message edited by: woodz428 ]</p>
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Old 10-23-2002, 05:48 PM
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usually to high float level, on holleys the fuel should just start to leak over the sight hole when the plug is out.
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Old 10-23-2002, 06:44 PM
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Get a fuel pressure regulator at the parts house. Usually you can pick one up for around $30. dial it down to 4-5 psi. An Edelbrock cant handle anymore than that.
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Old 10-27-2002, 01:09 PM
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I agree with Vaughn68 get a pressure regulator.
The Carter pump mite say 5 psi .put a gage on it and find the real output. I had one that was 15psi. also have a good filter on it, not one of those little see thru. Dirt will still be pushed thru it. They may look nice, but nice dont do the job.
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Old 10-28-2002, 05:18 PM
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I had the same problem you have and after the third carburator I decided to look else ware for the problem. It turned out the float in the fuel tank was coming apart, the filter over the gas line inside the gas tank was coming apart, and I had some rust from the tank itself. All this trash made it past the two filters I had in place, got to the carb and hung in the needle and seat assembly. On one carb this was obvious on tear down, on another it was not.

Disconect the gas line right where it goes into the carb. Put a clear plastic bottle over the gas line and turn the motor over several times. Hold the container up to a light source and see if you detect trash in the gas. This may contaminate each carb you are putting on the car.

If that doesn't fix the problem, I agree with the other posts. Check your fuel line pressure, needle and seat assembly, fuel level adjustment, and the float.

Its hard to believe you had numerous bad carbs, so I would check for trash in the gas like I described earlier.

In another case I had the fuel filter closest to the carb depositing trash to the carb every time I cranked the motor up. I cut the filter in half with a hack saw and it was completely full of trash.

Hope this gives you a new idea to check.
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