Stalling When Cold. (How long to warm up?)
Thread Starter
Instructor
Joined: Jun 2011
Posts: 107
Likes: 7
From: Toronto Ontario
Stalling When Cold. (How long to warm up?)
Hi-
My car is a 1971 454 4 Speed. Square port heads and LS6 Intake. Comp Cam 11-242-3 XE268H. 160Deg Thermostat
Carb: Holley Ultra Street Avenger 770CFM Vac Secondary, Electric choke.
When I have a cold start in the morning the choke comes on, the car has the fast idle. I start driving and after a couple minutes the choke comes off. (Choke cap fully left)
At this point the RPMs drop and the car stalls whenever I try and idle. This means I must feather the throttle at red lights. If I get moving the car heats up in around 7 minutes of driving and the temperature gauge goes to around 125F or so.
At this point the car will idle at around 800-850 no problem and drive really well.
I have played with the choke and extended the time as long as possible. Still the car won't heat up before the choke/fast idle comes off.
I thought maybe it could be the thermostat either stuck open (it is only a few years old), or is 160Deg too low?
Either I need the car to run better while still cold, or find a way to get the car heat up faster.
Any ideas?
My car is a 1971 454 4 Speed. Square port heads and LS6 Intake. Comp Cam 11-242-3 XE268H. 160Deg Thermostat
Carb: Holley Ultra Street Avenger 770CFM Vac Secondary, Electric choke.
When I have a cold start in the morning the choke comes on, the car has the fast idle. I start driving and after a couple minutes the choke comes off. (Choke cap fully left)
At this point the RPMs drop and the car stalls whenever I try and idle. This means I must feather the throttle at red lights. If I get moving the car heats up in around 7 minutes of driving and the temperature gauge goes to around 125F or so.
At this point the car will idle at around 800-850 no problem and drive really well.
I have played with the choke and extended the time as long as possible. Still the car won't heat up before the choke/fast idle comes off.
I thought maybe it could be the thermostat either stuck open (it is only a few years old), or is 160Deg too low?
Either I need the car to run better while still cold, or find a way to get the car heat up faster.
Any ideas?
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It does sound like the car is slow to warm up. Perhaps a new quality 180 thermostat is in order.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
Your "warm up issue" is well below 100 degrees. A thermostat has nothing to do with it. You already said it runs fine at 125*.
We assume you have played with the idle speed set screw. We assume the timing is spot-on.
Its a modified big block and it just may never idle until it warms.
We assume you have played with the idle speed set screw. We assume the timing is spot-on.
Its a modified big block and it just may never idle until it warms.
Thread Starter
Instructor
Joined: Jun 2011
Posts: 107
Likes: 7
From: Toronto Ontario
Your "warm up issue" is well below 100 degrees. A thermostat has nothing to do with it. You already said it runs fine at 125*.
We assume you have played with the idle speed set screw. We assume the timing is spot-on.
Its a modified big block and it just may never idle until it warms.
We assume you have played with the idle speed set screw. We assume the timing is spot-on.
Its a modified big block and it just may never idle until it warms.
It must be reading low meaning I think the thermostat could be an issue since it would delay the heating up to full operating temperature.
Idle speed I play with and it idles fine once warmed up. The idle mixture I will double check with a vac gauge.
Timing was set on the dyno.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I bet that if you put a 195 stat in, there would be no difference in warm up time. Then you wish it would run cooler.
Its not the stat ! Carb issues.
You also have just enough cam duration that the distributor Vac Adv is not being employed. In other words; low vacuum / little advance.
Its not the stat ! Carb issues.
You also have just enough cam duration that the distributor Vac Adv is not being employed. In other words; low vacuum / little advance.
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Thread Starter
Instructor
Joined: Jun 2011
Posts: 107
Likes: 7
From: Toronto Ontario
Thank you everyone for replies.
I checked the idle mixture screws and they were set correctly.
I raised the hot idle to 950RPM and the car ran fine when it was cold today.
That solved my issue - I guess my hot idle was a bit too low before.
I checked the idle mixture screws and they were set correctly.
I raised the hot idle to 950RPM and the car ran fine when it was cold today.
That solved my issue - I guess my hot idle was a bit too low before.
Le Mans Master
Joined: Mar 2004
Posts: 7,502
Likes: 1,509
From: Little Rock AR
Holley sells an electrodyne heat sensor that can vary the speed of the choke. You can try locating it in various locations to help the electric choke react to different engine start conditions. Worth a look.