Hemi Rebel
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You fixed it to death.
What could cause this?
- Thread starter 1337du0
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1337du0
Member
I haven't changed anything except the fuel pump since this started.
nm9stheham
Well-Known Member
Well dang.... at least it sounds like you may be zeroing in on the issue. Sounds like the pressure is indeed flooding the carb. I would be pulling the needle and seat to see if there is dirt in them; pretty common, and especially if you had crud in the pump......not sure where that came from with the new tank but it got there. If that does not fix it, then I think you need to put an inline pressure regulator between carb and fuel pump, set it to 5 psi, and see if that resolves it. I would do this before changing carbs.
If the regulator does the trick, then at least you know the carb is probably OK, and you need to then figure out why the new pumps are not behaving as they should. It does not explain why the new pump pressure is higher than spec. But I was thinking about this last night, and the pressure from a pump is normally spec'd at a certain fuel flow, and will have a higher pressure at lower flows than spec and lower pressure at flows higher than spec. What I can't answer for you is if this 9 psi from this particular pump is normal for a low idling flow rate; there ought to be some pressure regulation inside the pump itself and this does not seem to be working on the 2 new pumps you have had. I can't think of any way that you could install them so that they would put out excess pressure, only low pressure.
New stuff out of the box is not always right. I had 2 brand new batteries in a row that had internal shorts once upon a time. Edit to add: Perhaps it would be good to take this pump back, get a refund, and get a pump at NAPA. I.e., try a different pump.
BTW have you looked at the plugs? If it is indeed running rich, they ought to be pretty carboned up by now with flat black deposits. This would just confirm that.
If the regulator does the trick, then at least you know the carb is probably OK, and you need to then figure out why the new pumps are not behaving as they should. It does not explain why the new pump pressure is higher than spec. But I was thinking about this last night, and the pressure from a pump is normally spec'd at a certain fuel flow, and will have a higher pressure at lower flows than spec and lower pressure at flows higher than spec. What I can't answer for you is if this 9 psi from this particular pump is normal for a low idling flow rate; there ought to be some pressure regulation inside the pump itself and this does not seem to be working on the 2 new pumps you have had. I can't think of any way that you could install them so that they would put out excess pressure, only low pressure.
New stuff out of the box is not always right. I had 2 brand new batteries in a row that had internal shorts once upon a time. Edit to add: Perhaps it would be good to take this pump back, get a refund, and get a pump at NAPA. I.e., try a different pump.
BTW have you looked at the plugs? If it is indeed running rich, they ought to be pretty carboned up by now with flat black deposits. This would just confirm that.
Last edited:
1337du0
Member
Fuel regulator didn't do much. I set it at 5, 5.5, and then 6 psi and it ran best at 6 but it was still worse than when I don't have it on at all. I probably just need a regulator that can go to 7 psi for the best performance, but according to the service manual I should be fine from 5-7 psi. I plan on swapping out the carb tomorrow for an older on just to see what happens. If it works out, then I know that's the problem. If it doesn't fix anything then I know it isn't the carb at all. I will also check the plugs tomorrow, I have to get my sockets back from my in-laws house first.
The manual is right. At idle, pretty much any pressure below 7 will work fine. Pressure is important as the RPM comes up on hard acceleration. Above 7 lbs., as has been said, it's possible to blow the needle off the seat and flood it. Easy to check. When it dies, very slowly open the throttle and look down the bores with a flashlight. If the manifold floor is wet and vapor is rising out of the carb, it was flooding. If it's dry, it wasn't. You might also buy a cheap glass inline filter to replace your current one and see if it stays full of fuel or goes dry before the motor dies. This is as a TEST only, since those filters flow very little fuel. Was the tank to pump line replaced or blown out with plenty of air pressure?
The Horvaths
Well-Known Member
Float level triple-checked? Brass floats? Fluid in a float? Foam float? If so, get brass floats.
nm9stheham
Well-Known Member
Now I am wondering even more about the accuracy of the fuel pressure gauge being used. If it is reading high, then you may be alright all along on pressure (except the fast drop after shut-off). Carb swap may tell you something, but do the plug and visual check suggested too.
mopar 3 B
Well-Known Member
Back to you distributor problem setting points at 17 will get you to the closest required dwell setting. You really need to be checking dwell on point systems. Also make sure you have the correct cap and rotor. Chrysler used more than one distributor and most parts people are not old enough to know what points are alone if they are the right ones. Are you lubing the distributor cam? If not the points pad will wear premature causing dwell change. You need to fix one system at a time and quite throwing parts at it. Will be much cheaper in the long run and you will actually know what needed to be fixed when you're done. Did not mean to step on any toes here there have been a many good idea's just to may fixes at one time. Just my 2 cents.
miller
Well-Known Member
What mopar 3 B said...ditto.
Points still burning??? Trouble shooter gives plenty of reasons, not one fuel-related.
Any oil on the contacts are instant burn. Point type distribs require a high-temp grease on the cam, usually on a wiper felt on the points cam follower tab.
Also need to test, or replace the ballast resistor, since if it's bad, points will keep burning. Good luck on it!
Points still burning??? Trouble shooter gives plenty of reasons, not one fuel-related.
Any oil on the contacts are instant burn. Point type distribs require a high-temp grease on the cam, usually on a wiper felt on the points cam follower tab.
Also need to test, or replace the ballast resistor, since if it's bad, points will keep burning. Good luck on it!
wannadrag
Well-Known Member
Those chink points can go bad right away.Went with BW the 2nd time and all is good.Change to a good set of points and I bet the troubles will go away.
steve817
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I only glanced at "most" of the posts and did not see anything regarding the Venting of the fuel system. Is your return clear, what type of fuel cap are you using? Is your system vented? Steve
Hemi 354
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Please update us on what you found. I found this interesting and was following it for quite sometime.
1337du0
Member
This was definitely a fuel problem. Turns out my "Brand new" Carb decided to take a crap on me just after the warranty expired. Anyway, doesn't matter as I am putting in a freshly rebuilt 318. I am just going to keep this one and rebuild it in my spare time, lord knows it needs it anyway. Also, still haven't figured out why the fuel pump is putting out too much pressure but I am just going to switch to an electric.
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