Should there be fuel sitting in the intake? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GreenBay1921 · 01-10-2015, 05:09 PM

Should there be any amount of fuel sitting in the intake manifold, or is it flooded? ...I could see the fuel while looking down the carb, so I pulled the carb & there's a fair amount of fuel sitting in the intake.

Redline novdog · 01-10-2015, 07:14 PM

the intake floor should be wet.As far as pooling fuel no. You didn't state carb/intake motor/year. give us some info!

GreenBay1921 · 01-10-2015, 07:30 PM

Quote:

Originally Posted by Redline novdog

the intake floor should be wet.As far as pooling fuel no. You didn't state carb/intake motor/year. give us some info!

Sorry about that... I think its a 67 (that's what the insurance cards in the dash say

) It's a inline 6 (250). It has a 1 barrel carb. I think the carb is a 69 model based on searching the internet. Stock intake...

Redline novdog · 01-10-2015, 07:47 PM

Thank you for clarification. I am out ,never worked on a 1or 2 barrelcarb,but if they are like the 4bbl the the well plugs need to be coated. The float bowl will leak fuel while sitting.i do not kno if this is true for the 1/2 barrel carbs

geezer#99 · 01-10-2015, 09:00 PM

Was the motor completely warmed up when you saw the fuel or just started?

GreenBay1921 · 01-10-2015, 09:23 PM

Quote:

Originally Posted by geezer#99

Was the motor completely warmed up when you saw the fuel or just started?

It was not completely warmed up. I'm trying to get the engine worked out. I have been able to get it running, & at times it sounds great. I've even been able to drive it for a short distance. I had been partially hot wiring it until today. I drilled out the ignition switch so I can use it (still no keys yet). I was going to take it for another run & backed it out of the garage, but then it cut off on me. I was able to get it to crank, but it wouldn't run smoothly. Now I can't even get it to crank. It's getting gas to the carb & its get fire. I'm cleaning up some of the old wiring hack spots. The truck has been sitting for 20+ years. I've put new wires, plugs, cap, rotor, points, condenser on it. Still trying to solve the problem.

geezer#99 · 01-10-2015, 09:54 PM

Could just be a cold intake.
The fuel will puddle in the plenum if it's cold. The vaporized fuel from the carb goes back to a liquid.
You need heat in the intake to keep the fuel vaporized.
Is the heat riser working?

GreenBay1921 · 01-10-2015, 10:06 PM

Quote:

Originally Posted by geezer#99

Could just be a cold intake.
The fuel will puddle in the plenum if it's cold. The vaporized fuel from the carb goes back to a liquid.
You need heat in the intake to keep the fuel vaporized.
Is the heat riser working?

Sadly, I don't know what a heat riser is...

geezer#99 · 01-10-2015, 10:17 PM

It's an exhaust deflector plate below the intake plenum. The plate stays partly closed deflecting hot exhaust on the bottom of the plenum. You'll see your intake is bolted to the exhaust manifold right below the carb. The plate is thermostatically controlled with a counterweight.
Like in this link. It's just an example. Yours may be slightly different.
http://advrider.com/forums/showthrea...=653845&page=7
The heat riser is sometimes jammed open due to rust or someone jamming it open. You should be able to move it if you turn the counterweight.

GreenBay1921 · 01-10-2015, 10:24 PM

[IMG]

[/IMG]

This is what I have.

GreenBay1921 · 01-10-2015, 10:26 PM

Could that heat riser be in a shut position & prevent the truck from cranking?

GreenBay1921 · 01-10-2015, 10:34 PM

[IMG]

[/IMG]

I can't get mine to budge...

geezer#99 · 01-10-2015, 10:35 PM

No, it doesn't close off completely.
I see you don't have your choke hooked up!
Does it crank over and not fire?

GreenBay1921 · 01-10-2015, 11:04 PM

Quote:

Originally Posted by geezer#99

No, it doesn't close off completely.
I see you don't have your choke hooked up!
Does it crank over and not fire?

I have a new cable on the way. This one is broken...It has been running as of this morning. Right now it just turns over, with an occasional sputter. I'm redoing some of the wires that look bad. Maybe one of them will shine some light on it. ...Should I try to free up the riser lever?

geezer#99 · 01-10-2015, 11:09 PM

If it turns over and sputters try choking it by hand.
And you might need to advance the timing a bit to.
Rotate the distributor about 1/2 inch to help it fire up. Rotate it ccw.
I see your weather is a bit cool too!
That makes it harder to get them to start cold.
See if the riser will move but go easy on it.

GreenBay1921 · 01-10-2015, 11:31 PM

Thanks. I'll keep at it...

GreenBay1921 · 01-10-2015, 11:37 PM

I wrapped up the wiring & sprayed a shot of starting fluid in the carb & she fired right up & idled. The wires my have been the problem...

01-10-2015, 05:09 PM	#1
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Should there be fuel sitting in the intake? Should there be any amount of fuel sitting in the intake manifold, or is it flooded? ...I could see the fuel while looking down the carb, so I pulled the carb & there's a fair amount of fuel sitting in the intake. __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4

01-10-2015, 07:14 PM	#2
Redline novdog Registered User Join Date: Jan 2012 Location: Washington,Il Posts: 632	Re: Should there be fuel sitting in the intake? the intake floor should be wet.As far as pooling fuel no. You didn't state carb/intake motor/year. give us some info! __________________ It builds on my intelligence when I make a mistake, Boy am I building on it! '67 C-10,'70 Nova SS

01-10-2015, 07:47 PM	#4
Redline novdog Registered User Join Date: Jan 2012 Location: Washington,Il Posts: 632	Re: Should there be fuel sitting in the intake? Thank you for clarification. I am out ,never worked on a 1or 2 barrelcarb,but if they are like the 4bbl the the well plugs need to be coated. The float bowl will leak fuel while sitting.i do not kno if this is true for the 1/2 barrel carbs __________________ It builds on my intelligence when I make a mistake, Boy am I building on it! '67 C-10,'70 Nova SS

01-10-2015, 09:00 PM	#5
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Should there be fuel sitting in the intake? Was the motor completely warmed up when you saw the fuel or just started?

01-10-2015, 09:54 PM	#7
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Should there be fuel sitting in the intake? Could just be a cold intake. The fuel will puddle in the plenum if it's cold. The vaporized fuel from the carb goes back to a liquid. You need heat in the intake to keep the fuel vaporized. Is the heat riser working?

01-10-2015, 10:17 PM	#9
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Should there be fuel sitting in the intake? It's an exhaust deflector plate below the intake plenum. The plate stays partly closed deflecting hot exhaust on the bottom of the plenum. You'll see your intake is bolted to the exhaust manifold right below the carb. The plate is thermostatically controlled with a counterweight. Like in this link. It's just an example. Yours may be slightly different. http://advrider.com/forums/showthrea...=653845&page=7 The heat riser is sometimes jammed open due to rust or someone jamming it open. You should be able to move it if you turn the counterweight.

01-10-2015, 10:24 PM	#10
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Re: Should there be fuel sitting in the intake? [IMG][/IMG] This is what I have. __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4

01-10-2015, 10:26 PM	#11
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Re: Should there be fuel sitting in the intake? Could that heat riser be in a shut position & prevent the truck from cranking? __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4

01-10-2015, 10:34 PM	#12
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Re: Should there be fuel sitting in the intake? [IMG][/IMG] I can't get mine to budge... __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4

01-10-2015, 10:35 PM	#13
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Should there be fuel sitting in the intake? No, it doesn't close off completely. I see you don't have your choke hooked up! Does it crank over and not fire?

01-10-2015, 11:09 PM	#15
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Should there be fuel sitting in the intake? If it turns over and sputters try choking it by hand. And you might need to advance the timing a bit to. Rotate the distributor about 1/2 inch to help it fire up. Rotate it ccw. I see your weather is a bit cool too! That makes it harder to get them to start cold. See if the riser will move but go easy on it.

01-10-2015, 11:31 PM	#16
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Re: Should there be fuel sitting in the intake? Thanks. I'll keep at it... __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4

01-10-2015, 11:37 PM	#17
GreenBay1921 Registered User Join Date: Dec 2014 Location: McDonough, Ga Posts: 87	Re: Should there be fuel sitting in the intake? I wrapped up the wiring & sprayed a shot of starting fluid in the carb & she fired right up & idled. The wires my have been the problem... __________________ '68 Chevy C10 '06 Saleen Mustang #725 (Convertible) '04 Infiniti G35 '01 Infiniti QX4



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