Hot Start smoke!
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Hot Start smoke!
My '77 starts great when cold all the way down to 15 degrees or even up in the 50's or 60's when no choke is needed ! The car also starts fine when it has been sitting for an hour or two. The problem is that when the car has been sitting only 15 minutes or so it sometimes starts like it is all "loaded up" and smokes and then idles rough at about 600 RPM like a plug is fouled. After a minute or a quick acceleration all is well ! The smoke has a blue component to it like oil and is especially easy to see at night. The car has 101,000 miles, stock engine and Quadrajet. My "hot start" procedure is to hold the pedal about 1" down and it starts right up that way, better then any other method I've tried.
When cold I pump the pedal once or twice. This engine never smokes at all any other time. What does the forum say ?
When cold I pump the pedal once or twice. This engine never smokes at all any other time. What does the forum say ?
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
I am using the Summit 20-50w hot rod oil. I also thought about the valve seals but why would it be fine after sitting more then an hour or overnite or even for weeks ?? It never smokes then !!!
Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
MelWff, the smoke is black but has a slightly blueish component to it !
Mike, I will check the choke first as it is probably the most easy and cheapest suggestion so far. How can I check the carb dribbling issue, there is staining around the base of the carb.
Bashcroft, I do believe the carb may be leaking because if the car sits for more then 24 or 36 hours you have to crank it for a few seconds to start unless you pour about 1oz. of fuel in the carb then it starts instantly ! I also understand from some of my previous posts that this is a common quadrajet problem that several forum members are living with! But they did not mention a hot start problem just a harder start if the car sits for more then a day or two!
So this is not a classic sympton of leaky valve seals??
Mike, I will check the choke first as it is probably the most easy and cheapest suggestion so far. How can I check the carb dribbling issue, there is staining around the base of the carb.
Bashcroft, I do believe the carb may be leaking because if the car sits for more then 24 or 36 hours you have to crank it for a few seconds to start unless you pour about 1oz. of fuel in the carb then it starts instantly ! I also understand from some of my previous posts that this is a common quadrajet problem that several forum members are living with! But they did not mention a hot start problem just a harder start if the car sits for more then a day or two!
So this is not a classic sympton of leaky valve seals??
Last edited by BPHORSEGUY; Mar 25, 2012 at 05:33 PM.
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Thread Starter
Melting Slicks
Joined: Jul 2010
Posts: 2,762
Likes: 820
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Okay, First, thanks for all of the excellent advice so far! Now does this sound logical, if I shut the car down hot for say 10 or 15 seconds and try a restart if the problem is the carb leaking, or the seals leaking then the car should start fine because they haven't had enough time to leak.
If the problem is the choke then the problem should repeat. Let me know if there is a problem w/ my logic. Mike, I will check if the venturi is wet, this sounds like a very simple check!
If the problem is the choke then the problem should repeat. Let me know if there is a problem w/ my logic. Mike, I will check if the venturi is wet, this sounds like a very simple check!