Question on warm start struggle.

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Apr 30, 2010
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Limpopo RSA & Touchet USA
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www.huntingadventures.net
When it's freezing cold I pull the choke, pump the gas twice and turn the key, it cranks a couple times and fires right up.

When it's hot after running it, I just leave the choke in, turn the key and it fires right up.

When its been hot from running and sits of 30-60 min, that thing struggles to start. It's as if the engine is not sure if it wants the choke pulled or not? Is this normal, or am I missing something? It would seem easier to start when warm, but its not!
 
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Mar 4, 2011
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Dallas, Texas
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That is a dirty EGR most likely. When I have that problem it is because the EGR wont seal. I am basing this on my Corvette knowledge.

pR


When it's freezing cold I pull the choke, pump the gas twice and turn the key, it cranks a couple times and fires right up.

When it's hot after running it, I just leave the choke in, turn the key and it fires right up.

When its been hot from running and sits of 30-60 min, that thing struggles to start. It's as if the engine is not sure if it wants the choke pulled or not? Is this normal, or am I missing something? It would seem easier to start when warm, but its not!
 
Joined
Aug 26, 2009
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11,648
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down in a hole.
I have this trouble w/ my 86 2F driven 55 series. I have no carb fan, I am certain it is vapor lockish.....fuel in the bowl boils away while setting there hot w/ no air flo..... I think the carb fan would help immensely. Yet to try it to see. the engine compartment is a very warm place after a nice drive, and the exhaust is awfully close to the intake/carb.....HTH
 
Joined
Dec 29, 2005
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1,484
Location
Craig, CO
I'v struggles with this for years. I think the carb fan is a huge help. On my 60 series, it is very tight and hot under the hood. But it has never had a problem cranking over and startign no matter the conditions because the carb fan always works.

My 73 40 series is a different story. Typically I can get it started after sitting a bit, like 30-50 minutes as the original poster described, but then it will stall and die about half a block down the street. I think it is the float bowl boiling off and possibly vaporization of the fuel lines. Putting my return line back on helped, as did hooking the tank vent back up on the gas tank. I have not driven it much lately, but I always wanted to get some of that line insulating sleeves from summit and cover the fuel lines at least. I may experiment with a 2F carb spacer/heat shield some too, to see if that will divert some of the rising heat from the manifold away from the bowl.
 
Joined
Oct 5, 2009
Messages
344
Ethanol in the fuel? Ethanol also has a lower boiling point than regular gas, which can often result in vapor lock in the heat of summer, and even when engines overheat.
 
Joined
Feb 11, 2004
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1,190
Location
Tampa
This topic comes up every summer - install/reinstall your carb fan - it was put there by Toyota for a reason. I live in Florida and had the same problem prior to reinstalling the carb fan. That said, I didn't use the factory "fan computer" - instead I bolted up an adjustable thermostat from the parts store for less than $30 and it starts every time in 90+ degree summer heat.
 
Joined
Jan 25, 2011
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9
Location
Denver CO
I have been slowly looking into a 12 V delay Relay control for the fan. If I find the correct way to do it I will post the cat # and brand for the relay. It is getting warmer in Colorado and i am finding the same problem with my 78 FJ40.
 
Joined
Feb 11, 2004
Messages
1,190
Location
Tampa
I have been slowly looking into a 12 V delay Relay control for the fan. If I find the correct way to do it I will post the cat # and brand for the relay. It is getting warmer in Colorado and i am finding the same problem with my 78 FJ40.

I don't have the part number but I connected a normally closed relay to the ignition switch - i.e. when the ignition is on - the cooling fan has no power but when the ignition is off (AND) the thermostat reads high enough, the cooling fan runs until the temp drops - works well.
 
Joined
Jul 24, 2005
Messages
346
Location
Southern Ontario, Canada
Insulation

Over here we hit 50 deg C a lot of the year and it's even hotter on the pavement. Vapor lock can be drastically reduced by insulating the fuel line to the carb.
I used a foam for a/c piping and then a foil tape over that.
Heat from the engine / manifolds where the fuel line passes over vapoizes fuel and floods the carb.
Guaranteed to work on the first run.
 
Joined
Nov 14, 2008
Messages
266
Location
Alton, IL (near St Louis, MO)
Over here we hit 50 deg C a lot of the year and it's even hotter on the pavement. Vapor lock can be drastically reduced by insulating the fuel line to the carb.
I used a foam for a/c piping and then a foil tape over that.
Heat from the engine / manifolds where the fuel line passes over vapoizes fuel and floods the carb.
Guaranteed to work on the first run.

This seems to be the quickest/easiest/cheapest solution. Will give it a shot. Thanks desertpat
 
Joined
Jul 24, 2005
Messages
346
Location
Southern Ontario, Canada
heat rises

Heat rises .... so focus on insulation of the bare fuel line at the upper side from the fuel pump and above the hot engine and manifold, and all the way to the carb, including the nut connection.
A heat shield would help as well but most of the problem will go away with good insulation.
We don't have factory carb fans here - it wasn't an option.
Good luck and let us know.
 

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