I have a 69 L-46 that I have put back to original. It had a leaking Holley on it and an Aluminum intake when I bought it, but it could sit for a month or so and start right up.I put the correct intake on it with an incorrect q-jet and it started o.k. Then I bought a 7029207 brand new in the wrapper carb. and put on it.This is when my hard start problem started.I have put a new correct A/C fuel pump on it, plug's, point's ,wire's and when it sit's for more than a few day's you have to pump the heck out of it to get it to start, I mean 15-20 time's.By the way I have put a kit in the new carb to no avail. Any and all help will be appreciated, thank's in advance. Tom #41491
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Re: Hard start problem ?
do you have the AC "check valve" type fuel filter in the carb? does the fuel pump have a return line to the tank and if it does and you have a fuel filter without the check valve the bowl could be draining back into the fuel system. these carbs use a "windowed" needle seat that has a opening below the fuel level and that is how the gas leaves the bowl. JMHO -
Re: Hard start problem ?
Clem
Yes I do have the AC type filter in the carb. I do not have the correct external fuel filter. That is my next project. By the way I have the return line to the tank plugged off.This is the same fuel filter that I had on it before changing carb's and I had no problem. I am going to change it back to the GF432 to be correct.Thanks for your help. TomComment
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Re: Hard start problem ?
check the bottom of the main body of the carb and see if it had press in brass cup type plugs or spun in aluminum. if they are the brass cup type you will need to epoxy them to prevent leaks. the spun aluminum do not leak and it may just be heat soak boiling the gas from the carb. GM made a heat shield for some corvette applications that bolted between the carb and the manifoldComment
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Re: Hard start problem ?
have a 70 L-46 witht the same issue. Also once it starts the idle will lope up to 1500 and stall if I don't feather the throttle. Once warm it runs fine. Clem what is the check valve filter?Comment
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Re: Hard start problem ?
the fuel filter has a spring loaded check valve built into the inlet to prevent fuel for running back out of the filter. these are the filters that fit inside the Q jet carbsComment
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Re: Hard start problem ?
I have a paper element filter in the housing. There's also a spring. I thought the filter was just one way. (opening facing the fuel line) Is this what you mean? Does the spring have a certain orientation?Comment
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Re: Hard start problem ?
the check valve filters have spring loaded disk inside the opening where the fuel enters the filter. the check valve can be removed as a unit,plastic housing,spring and a disk that seal the opening into the check valve. the standard filter just has a open hole where you can see inside the filter.Comment
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Still available? *NM*
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Re: Still available?
as far as i know. i would think that all the fuel filter manufactures would have them. GM part # GF 470 for the short one and GF 471 for the long oneComment
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Re: Still available?
Clem
Does it make a difference which fliter you use? I don't know if I have the long or the short. I assume the spring would make up the difference!But would the short one in the wrong application let the fuel leak back? Thank's in advance.TomComment
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Re: Still available?
no you need the size that came in your carb,they come in 1" long,GF 470 and 2" long,GF 471. what is the carb number and i can tell you from that which one you needComment
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Re: Still available?
Clem the carb number is 7029207 which is correct for the car. It is a newer carb than a 69 though. I believe the date number on it is 1188. If that is important I can check.Maybe I have to short a filter in there and this is what is letting it drain back. I know from pouring a little gas down the vent pipe that the bowl is low or empty. After I do this it will start right away.The problem is only when cold and after it has sat for a week or so.Thanks for your help. TomComment
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Re: Still available?
the orignal 7029207 used the short filter but i am not sure if the later replacememt carb would take the sameComment
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Re: Still available?
Thanks Clem that is what I have in there now. TomComment
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