Stalling When Cold

[goodnigh]

The 351C 4V quench starts fine in cold weather but after maybe 5 min

driving, the engine will stall at idle. After 5 min the electric choke has

come off so I don't think it is a choke problem. I was smelling gas

after shutting down the engine so I leaned out the choke and that

fixed the smell but the car still stalled. The intake is stock iron and

the Holley 770 has an aluminum spacer. The air cleaner is a bonnet

with K&N filter for cosmetic reasons. I am thinking I need to put the

stock air cleaner with heated snorkel back on, at least for the winter.

This is northern California but when need to scrape ice off your

windshield in the morning, it's cold.

mike

 

[MotoArts]

Does it continue to stall when hot, as in 10-20 minutes run time?

Does it want to stall only at:

- idle,

- in park or neutral,

- when just putting in gear, or

- when you're beginning to accelerate, too?

 

[goodnigh]

Does it continue to stall when hot, as in 10-20 minutes run time?

Does it want to stall only at:

- idle,

- in park or neutral,

- when just putting in gear, or

- when you're beginning to accelerate, too?

It only stalls when it has not had enough time to properly warm up.

My 8-10 minute drive to work after the choke is off is apparently

not long enough. It runs fine if I give it a little gas and I could adjust

the idle screw but then it would idle too fast once it has warmed up.

If we keep adjusting the carb, when the weather does warm up it

won't run right. Besides the electric choke there is probably a

reason Ford used a heated snorkel. I don't remember this being a

problem when I had a 670 cfm on it but now I have a 770 and the

new engine has a cam and is quench.

The engine runs great after warm up it's just that 5-10 minutes when

the temp is near freezing.

mike

mike

 

[Wolverine]

What is your engine temperature after 5 minutes?

Here in California, cold to us is 45 degrees. What is cold to you?

 

[MotoArts]

If you're talking bad idle only in the "transition" minute between 120-180* water temp, personally I'd leave it alone and 2 foot it to keep it running.

Or, the rough adjustment way would to simply dial a little tension back on the choke. Just a weeee bit, and see if that helps.

How about upping the primary main jet one size (small chance it may work only if the stumble is above idle)?

Is the manifold heat crossover functional?

Yes, you'll have to readjust come summertime. One of the reasons that modern fuel injection spoils us all.

I never had major troubles with carbed stuff in the cold, and that's in Pittsburgh cold... I always removed the flexy heat tube to the snorkel on all of my stuff, although it may have helped a bit.

Give 'er an extra 60 seconds warm up before departing...

 

[Wolverine]

Another thought, does your vacuum advance on the distributor utilize the thermostatic control? This is the 3 outlet plug on the intake manifold, passenger side front.

If so, perhaps this is not functioning and giving you the proper advance once the engine is warmed up?

 

[goodnigh]

What is your engine temperature after 5 minutes?

Here in California, cold to us is 45 degrees. What is cold to you?

Never measured the engine temp but it gets warm enough for

the defroster to melt ice on the windshield in 5 minutes.

Where I live in California 25 would be considered cold.

mike

If you're talking bad idle only in the "transition" minute between 120-180* water temp, personally I'd leave it alone and 2 foot it to keep it running.

Or, the rough adjustment way would to simply dial a little tension back on the choke. Just a weeee bit, and see if that helps.

How about upping the primary main jet one size (small chance it may work only if the stumble is above idle)?

Is the manifold heat crossover functional?

Yes, you'll have to readjust come summertime. One of the reasons that modern fuel injection spoils us all.

I never had major troubles with carbed stuff in the cold, and that's in Pittsburgh cold... I always removed the flexy heat tube to the snorkel on all of my stuff, although it may have helped a bit.

Give 'er an extra 60 seconds warm up before departing...

It is only a problem when the temp is in the 30's. At 50 or above it

is not a problem. I will probably put the heated working snorkel

system back on for now. The picture below shows a bonnet with K&N

filter so I am sucking too much cold air. The quench head with 770

Holley and "mild" cam is not happy in cold weather at least for the

first few minutes.

mike

 

[c9zx]

Mike, Have you tried adjusting the fast idle speed screw associated with the choke? Chuck

http://www.holley.com/data/Products/Technical/199R10487-1rev4.pdf

page 9, figure 10. Just a thought.

 

[hyena429]

My mustangs 4v ....cold blooded....I didnt dare put it into drive till it got past 140 or 150ish on the temp gage even if i was in a hurry...Or it would stall or buck like a pig..lol...I owned and drove it for 18 years now...And she was always cold blooded even with the dif carb i put on it later "thinking some issues was my carb anyways" Nope still didn't like to move till she was warmed up most of the way.

 

[goodnigh]

Mike, Have you tried adjusting the fast idle speed screw associated with the choke? Chuck

http://www.holley.com/data/Products/Technical/199R10487-1rev4.pdf

page 9, figure 10. Just a thought.

The way the carb is now set up it idles about 1600 on startup.

Step on the gas to set the choke then start.

Are you suggesting I should set the fast idle to maybe 2000?

mike

 

[goodnigh]

The problem appears to have fixed itself.

Drive to work and the tach still reads 1000

so the choke is working now. Did not change

anything. The only difference being when I

had problems the temp was around 35. Now

the temp is around 30. Maybe the colder air is

causing the choke to open more slowly. It is

going to warm up in the next few days, maybe

upper 30's so we will see. Very perplexing.

mike