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Hard start

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Old May 22, 2022 | 12:15 PM
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Klim19721's Avatar
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Hard start

So my 86 T/A carb starts hard after sitting after it has been driven I have moved all fuel lines and wrapped starter with no change
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Old May 22, 2022 | 12:52 PM
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From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Hard start

Describe the hard start. Doesn't crank...cranks slow.... cranks very fast....spits and sputters while cranking... or a video
Gotta give us something to go on.
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Old May 22, 2022 | 01:22 PM
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Re: Hard start

Originally Posted by aliceempire
Describe the hard start. Doesn't crank...cranks slow.... cranks very fast....spits and sputters while cranking... or a video
Gotta give us something to go on.
So after sitting after warmed up and parked I have to floor it to start almost for a minute
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Old May 22, 2022 | 03:32 PM
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Car: Yes
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Transmission: Sometimes
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Re: Hard start

Sounds like the fuel reaching the carb gets very hot while it sits and immediately spews into foam when it goes from fuel system pressure (4 psi or whatever) to atmospheric. Kinda the same deal as shaking up a closed warm Coke bottle and then popping off the top.

Try creating the conditions that produce it. For me, it has always been, driving it around on a hot day in traffic esp with the AC on, shutting off the motor, then coming back and trying to start it after maybe 10-15 min. Like going to the store or something. While waiting, pop the air cleaner lid off, and watch down into the carb while your assistant tries to start it. If you see gaoline bubbling up out of every hole in the top of the carb and flooding into the intake, then that's what it is.

Very common. Usually derives from the block heating up the fuel pump, in my experience.

Try adding a 2nd fuel pump gasket. If that helps, get one of these. https://www.cantonracingproducts.com...vy-fuel-pumps/

And, if any of your fuel lines are routed closer to any exhaust parts than they were when stock, look into moving or shielding them.
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Old Jul 11, 2022 | 10:26 PM
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From: FLORIDA
Car: 85 Z28 Sport
Engine: 383
Axle/Gears: 3.73
Re: Hard start

depending on the carb, get a quick fuel insulator and a 1/2 in carb adaptor that is made of either aluminum or composite, sold at holly or the other places for 114 bucks plus tax. if you have a steel line to the carb, make it rubber from the fuel pump, if that helps maybe an air gap intake will help too


Last edited by 85Z28SPORT; Jul 11, 2022 at 10:30 PM. Reason: adding words
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