'71 Choke
Thread Starter
Instructor
Joined: Dec 2006
Posts: 132
Likes: 0
From: Virginia Beach, VA
'71 Choke
My ´71 350/270 does not increase its RPM during cold start (Q-Jet carb). It seems as if the choke panel works as it should – it slowly opens more and more during warming up. But why doesn’t the RPM increase during cold start? Sometimes, I have to restart the engine a few times before I can keep it running. If I’m lucky and keep it running it’s because I work the throttle a lot.
Something is wrong here. Anybody knows what?
Thanks.
Something is wrong here. Anybody knows what?
Thanks.
Drifting
Joined: Sep 1999
Posts: 1,970
Likes: 91
try adjusting the fast idle screw. If your car won't run when you first start it, but the choke closes, turn the screw a bit before you start. May give you an idle so you can then adjust to the fast idle speed. I believe 1500 rpm.
I had this pic for something else but it shows the adjusting screw. I can't edit the photo, so I'll explain where it is. Follow to the right of where the red line ends at the lock out lever. Directly right you can see a large slotted screw.(slot at 11 o'clock). Just right of that scew is an arm with a sort of hooked end.(3 o'clock position from the large screw). Diretly below that arm is a smaller screw. You're looking at the side of the screw head, and if you follow left from the head, you can see where the threaded end is. That threaded end actually pushes against the lever adjusting the fast idle. Hope it wasn't too confusing.
I had this pic for something else but it shows the adjusting screw. I can't edit the photo, so I'll explain where it is. Follow to the right of where the red line ends at the lock out lever. Directly right you can see a large slotted screw.(slot at 11 o'clock). Just right of that scew is an arm with a sort of hooked end.(3 o'clock position from the large screw). Diretly below that arm is a smaller screw. You're looking at the side of the screw head, and if you follow left from the head, you can see where the threaded end is. That threaded end actually pushes against the lever adjusting the fast idle. Hope it wasn't too confusing.
Thread Starter
Instructor
Joined: Dec 2006
Posts: 132
Likes: 0
From: Virginia Beach, VA
Thanks, Dennis - I could easily follow your way to the thread.
But you state 1500 RPM as the fast idle speed - I'm not sure I follow this one.
However, I will try adjusting the screw (clockwise, or what?).
Thanks again.
But you state 1500 RPM as the fast idle speed - I'm not sure I follow this one.
However, I will try adjusting the screw (clockwise, or what?).
Thanks again.
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
In 1971 the Controlled Combustion System (CCS) and the Transmission controlled Spark (TCS) are combined as the Combined Emission Control or CEC. It consists of a transmission control switch, a time delay relay, an engine temp. switch, and a valve that comvbines the TCS with the CCS. The CEC soleniod controls the vacuum advance to the distributor. All of these work along with each other to lower emissions. My guess would be in the time delay relay on the firewall. Check the connections at the coolant temp. switch and the solenoid at the carb. Just a guess but I hope this helps. WB
Book shows 1350 at fast idle
Book shows 1350 at fast idle
Drifting
Joined: Sep 1999
Posts: 1,970
Likes: 91
1500 RPM(1350 per warbonnet). You can use your tach to set this.
Warbonnet gives you good advise also. I figured you could start with the simple thing, before you get into "the world of the early emissions"
