Need carb/fuel help!
I have checked the archives and have found nothing for my problem. I have a '66 roadster 327/300 with holley carb. Car starts fine and idles at 750rpm when cold and drives great. After getting to operating temp or driving it for a while I shut it down. Within a hour or less then re-starting, it is a different car! Barely keeps 500rpm idle. I have to keep my foot one the gas a lights to prevent stalling. It backfires thru carb. and bogs down when goosing it. Local service station looked and said no vacuum leak and saw debris in float. He suggested a re-build of carb. Another mechanic said it sounds like it isn't getting fuel or not enough when the engine is hot and that it is running lean with too much air and not enough fuel. He said it could be fuel line or gas tank issue which he called a "hot soak problem" Maybe fuel pump, filter, something in the delivery system, but not the carb. ANY SUGGESTIONS on which way to go? THANKS!
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Re: Need carb/fuel help!
Jerry,
Search "heat soak". You'll find plenty of articles. The fuel in your carburetor is percolating after you let it sit after driving. Fairly common issue with today's fuel. Have you been experiencing this for awhile? Have you tied open your heat riser? Have you plugged the two holes in the intake valley under your carb? You'll find many more helpful hints in the files.Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star Regional -
Re: Need carb/fuel help!
Thanks Leif.. I checked and don't see anything that addresses my problem, but I'll take your advice on percolating. Would re-building carb take care of that. This is not a problem in colder weather. This condition has been for 2-3 years, but getting worse of late.I don't use any fuel additives.Comment
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Re: Need carb/fuel help!
Jerry,
Wire the heat riser open and get the engine to operating temperature and set the idle 6-700rpm them adjust the emulsion screws on the primary metering block. These screws need to be adjusted after the engine is fully warmed so the plenum is good and hot.Comment
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Re: Need carb/fuel help!
Jerry,
You can start here
Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star RegionalComment
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Re: Need carb/fuel help!
Thanks Leif. What does the heat riser look like?Comment
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Re: Need carb/fuel help!
It's located on the passenger side of the engine between the exhaust header and the exhaust pipe. It's at about the same height/area as the spark plugs. It's a cast iron piece with a weighted spring on it that over time tends to rust and seize. Most just wire it open with some strands of stainless steel wire and allow the 100% exit of all high temp exhaust full time.Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star RegionalComment
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Re: Need carb/fuel help!
Jerry,
I hate to be an *******, but you really need to get your head into this hobby and learn more about YOUR car. You have referenced two "mechanics" that probably have NO knowledge and experience with cars like yours. I have found that most "mechanics" these days know about things like fuel injection on Toyota's that they learned from watchin some factory video. Don't be afraid to get your hands dirty and dive into it. That's what I did, and I am proud to say that my cars ('67 L79 and '68 base motor) run as good as any out there. This is after is was let down by "mechanics" more times than the 3 strippers I have known.Comment
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Re: Need carb/fuel help!
Thanks Leif! I got it!Comment
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Re: Need carb/fuel help!
Sounds like you have had an interesting life Den. I am mechanically challenged and have lost some brain cells after my cancer and 4 months of chemo, but I am trying to teach my 72 year old brain new stuff. Your points on mechanics are well deserved for the most part. I've had the car for five years and nothing has been a challenge until now. Thanks for your advice.Comment
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Re: Need carb/fuel help!
Jerry,
Both of Leif suggestions in his first post should be tried and will most likely solve your problem. I will make another suggestion, check out http://pure-gas.org/ or Avgas for a an ethanol gas alternative. It will help more than just your current problem.Comment
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Re: Need carb/fuel help!
Jerry
I live in the Palm Springs area.
If you in so cal area, I'd be happy to show you what is involved.
Or I can explain in more detail over the phone
I just finished setting up my 66 327/300 holley
I M me and I'll send you my contact infoComment
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Re: Need carb/fuel help!
Thanks Tony, but I'm in New York. I am having a corvette mech. have at it tomorrow. I'll let u know, but I appreciate your offer.Comment
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