1974 CJ5 AMC 304 - cold start stalling - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 89 Old 04-25-2014, 11:26 AM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
1974 CJ5 AMC 304 - cold start stalling

Hi, I'm back! You guys helped me figure out I'd burned out my ignition coil when my Jeep wouldn't start two weeks ago.

In the time since then I've driven it nearly every day. It runs really well...when it's warmed up.

Here's what it's doing. Some of it may be just normal old carb engine stuff. But I think I might need to adjust something with the choke or carb, but not sure. Because I only started getting to know old engines in the past two weeks.

It's got an electronic starter, just FYI. So, no manual choke. It's also got an auxillary fuel pump for off-roading, which I don't do. And a recently rebuilt Holley carb (2 barrel) but I don't know what kind.

Also, I live in Atlanta where it rarely gets very cold and it can be somewhat humid during the warm months. And where it rains a lot in the Spring.

So, when I start it up in the morning, or after it's been sitting for 8-9 hours while I'm at work, the initial idle is unstable and it stalls a lot. The starting procedure, according to the guy I bought it from (who's a Nissan mechanic), is I just need to pump the gas pedal once and it should start right up.

So, I pump the pedal once. It starts up. Then it idles all thready and dies. I go through this a few times before getting it going. When I try to feather the gas pedal it seems to make it worse, like I'm drowning it. I am not sure if I am just doing that wrong...or if I need to release the clutch more than I'm doing...or what.

After I do get it going it runs a little sluggish for a couple minutes. It might be in my head but I feel like if I let the RPMS in 1st gear get a little high for the first couple of dead stops it clears up the sluggishness faster. After that, it runs fine and no stalling problems.

If it's humid outside, like if it's rainy or if it's just plain old southern humid, then it's worse and it takes a lot longer for it to stop stalling and stop being sluggish.

I feel like this has got to be something I can fix with some adjustment to the carb, or something. Or perhaps this is all just old Jeep stuff and I just need to learn to work it better.

Can anyone help me?

Thanks,

Jen

sabbyATL is offline  
Sponsored Links
Advertisement
 
post #2 of 89 Old 04-25-2014, 12:27 PM
19jeep85
Registered User
1985 CJ7 
 
Join Date: Feb 2010
Posts: 297
One pump may be fine on a fuel injected Nissan, but on an old carburated engine it is too few. Pump it two or three times, then halfway to the floor to set the choke and try to start it. Once it starts, leave the pedal alone for a few minutes until the idle increases then you can tap it to release the choke.

The heart of the wise inclines to the right, but the heart of the fool to the left .
19jeep85 is offline  
post #3 of 89 Old 04-25-2014, 12:48 PM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by 19jeep85 View Post
One pump may be fine on a fuel injected Nissan, but on an old carburated engine it is too few. Pump it two or three times, then halfway to the floor to set the choke and try to start it. Once it starts, leave the pedal alone for a few minutes until the idle increases then you can tap it to release the choke.
Thanks!

So, for clarification - after pumping it a couple times and pushing halfway, do I hold until after I start, then release and leave it alone and let it idle, then another half push?
sabbyATL is offline  
 
post #4 of 89 Old 04-25-2014, 12:52 PM
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant
Posts: 18,083
Your fast idle setting might be too low. Most carb engines should idle around 1750 rpm when on fast idle. Then as it warms up to half open choke plate, you can tap the pedal and it should go to 1200 rpm on the next step of the fast idle cam then a bit later when it is wide open it goes to idle. You can watch it open with the air filter off.

You should post some photos of the side of your carb so we can point you to the fast idle cam and adjusting screw. It is a lever with steps on it that moves when the choke closes and the gas pedal is to the floor. The second step will usually have an arrow on it to show you where to put the set screw when you adjust it.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(10 new albums added Sept 16/10)
Mike Romain is offline  
post #5 of 89 Old 04-25-2014, 01:00 PM
19jeep85
Registered User
1985 CJ7 
 
Join Date: Feb 2010
Posts: 297
Nope, pump it; pump it real good!:-) Then half way to the floor (which should set your choke) and release the pedal, then turn the key over and start it. Don't touch the pedal again until you hear the idle increase.

If it has sat for a while, you may also want to turn over the engine by turning the key without giving any gas until you see a rise in oil pressure, then pump it good, go half to the floor and do as above.

If you have to do this a couple of times, and it doesn't want to start, you may end up flooding the carb (you may even smell gas) at which point you floor it and hold the pedal down while you start it which will clear your carb.

The heart of the wise inclines to the right, but the heart of the fool to the left .
19jeep85 is offline  
post #6 of 89 Old 04-25-2014, 01:14 PM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by 19jeep85 View Post
Nope, pump it; pump it real good!:-) Then half way to the floor (which should set your choke) and release the pedal, then turn the key over and start it. Don't touch the pedal again until you hear the idle increase.

If it has sat for a while, you may also want to turn over the engine by turning the key without giving any gas until you see a rise in oil pressure, then pump it good, go half to the floor and do as above.

If you have to do this a couple of times, and it doesn't want to start, you may end up flooding the carb (you may even smell gas) at which point you floor it and hold the pedal down while you start it which will clear your carb.
OK, I'll give this a shot. I drive it nearly every day. But I'll keep the other in mind for when it does sit, since I do travel for work...usually no more than 2 weeks at a time.
sabbyATL is offline  
post #7 of 89 Old 04-25-2014, 01:15 PM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by Mike Romain View Post
Your fast idle setting might be too low. Most carb engines should idle around 1750 rpm when on fast idle. Then as it warms up to half open choke plate, you can tap the pedal and it should go to 1200 rpm on the next step of the fast idle cam then a bit later when it is wide open it goes to idle. You can watch it open with the air filter off.

You should post some photos of the side of your carb so we can point you to the fast idle cam and adjusting screw. It is a lever with steps on it that moves when the choke closes and the gas pedal is to the floor. The second step will usually have an arrow on it to show you where to put the set screw when you adjust it.

Hi Mike!

So, I'm going to give 19jeep85's suggestion a try first, since it's possible I am being a little to precious with starting it. If that doesn't work I'll come back with a photo of my carb.

Thanks!

Jen
sabbyATL is offline  
post #8 of 89 Old 04-25-2014, 02:14 PM
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant
Posts: 18,083
Quote:
Originally Posted by sabbyATL View Post

Hi Mike!

So, I'm going to give 19jeep85's suggestion a try first, since it's possible I am being a little to precious with starting it. If that doesn't work I'll come back with a photo of my carb.

Thanks!

Jen
Mine takes 2 pumps at least, if it is cold out more pumps then foot off the gas and vroom, even at -30.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(10 new albums added Sept 16/10)
Mike Romain is offline  
post #9 of 89 Old 04-25-2014, 02:26 PM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by Mike Romain View Post
Mine takes 2 pumps at least, if it is cold out more pumps then foot off the gas and vroom, even at -30.
I'll going to try all this out tomorrow morning and let y'all know, either way.

Thanks!
sabbyATL is offline  
post #10 of 89 Old 04-25-2014, 02:29 PM
19jeep85
Registered User
1985 CJ7 
 
Join Date: Feb 2010
Posts: 297
It does sound like the choke isn't being set correctly, and with the ethanol fuel these days, the fuel leans out the burn and the choke is meant to richen the mixture; so no choke + too little fuel in the bowl + ethanol sounds like your starting problem.

I don't know if you can get non ethanol fuel in Atlanta, but try to find fuel with the least amount you can and maybe even get an additive meant to stabilize the ethanol.

The heart of the wise inclines to the right, but the heart of the fool to the left .
19jeep85 is offline  
post #11 of 89 Old 04-27-2014, 09:38 AM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by 19jeep85 View Post
It does sound like the choke isn't being set correctly, and with the ethanol fuel these days, the fuel leans out the burn and the choke is meant to richen the mixture; so no choke + too little fuel in the bowl + ethanol sounds like your starting problem.

I don't know if you can get non ethanol fuel in Atlanta, but try to find fuel with the least amount you can and maybe even get an additive meant to stabilize the ethanol.


So I tried this starting method both yesterday and today and it's a no go.


I pump the pedal 4 times, half press, start, and then it idles itself lower and lower until it turns itself off.

I basically start it again and then feather the pedal until it idles without rpming down.
sabbyATL is offline  
post #12 of 89 Old 04-27-2014, 10:31 AM
19jeep85
Registered User
1985 CJ7 
 
Join Date: Feb 2010
Posts: 297
Quote:
Originally Posted by sabbyATL
So I tried this starting method both yesterday and today and it's a no go. I pump the pedal 4 times, half press, start, and then it idles itself lower and lower until it turns itself off. I basically start it again and then feather the pedal until it idles without rpming down.
Pull your air filter off and verify if the choke is actually set, do as you have but don't turn the key. The two flaps in the throat of the carb should be laying flat, if they aren't flat your choke isn't setting.

The heart of the wise inclines to the right, but the heart of the fool to the left .
19jeep85 is offline  
post #13 of 89 Old 04-27-2014, 10:44 AM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by 19jeep85 View Post
Pull your air filter off and verify if the choke is actually set, do as you have but don't turn the key. The two flaps in the throat of the carb should be laying flat, if they aren't flat your choke isn't setting.

I can do this with a warm engine, right?
sabbyATL is offline  
post #14 of 89 Old 04-27-2014, 11:00 AM Thread Starter
sabbyATL
Registered User
1974 CJ5 
 
Join Date: Apr 2014
Location: Atlanta
Posts: 941
Quote:
Originally Posted by 19jeep85 View Post
Pull your air filter off and verify if the choke is actually set, do as you have but don't turn the key. The two flaps in the throat of the carb should be laying flat, if they aren't flat your choke isn't setting.

Did it just now after getting home with it. Flaps stay open with a half press.
sabbyATL is offline  
post #15 of 89 Old 04-27-2014, 11:41 AM
babytank31
Registered User
1978 CJ5 
 
Join Date: Nov 2008
Location: nc
Posts: 185
When you say auxiliary fuel pump do you mean an electric fuel pump? If so, before you try to start the motor turn the key to the ignition position and give it a few seconds. You may have something causing your fuel bowls to lower the fuel level in them. You may or may not have site windows on your carb to check the fuel bowl level. You have to remember that a jeep is not like our modern automobiles. Each has its own personality per say, making them each unique it it's own way. Like the other guys said, check your choke, floats and fast idle settings to make sure you are set up correctly. You may have to let it run on high idle for a few minutes before you take off. Jeep will tell you how it wants to run and be driven. You just have to set back and take in what it is saying to you. Best of luck with it.
babytank31 is offline  
Reply

Tags
304 , cold start , stalling

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome