Cold=Runs Like Crap, Warm=Runs Good - Help! - JeepForum.com

 
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post #1 of 10 Old 11-21-2008, 07:43 AM Thread Starter
CheapSunglasses
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Cold=Runs Like Crap, Warm=Runs Good - Help!

I rebuilt my crapola Carter and reinstalled on my 4.2 when the weather was in the 60' and she ran fine.

Now that the weather dips into the 30's at night and barely into the 40's during the day, she runs HORRIBLE until warmed up.

Symtoms are: At startup she sputters so bad I have to feather the gas for 30 seconds until she clears out and runs fairly steady....I start to drive and come to the end of my street and she races to about 1500 RPMs....I then drive for a half a mile or so and she starts to studder and miss, so I downshift to get the RPMs up and she kinda clears out....I drive a little wile longer and come ot a stop sign, she races to about 1100 RPMs and then slowly drops until she stalls....I start her back up and drive to my destination and she races at about 1500 RPMs until I pull into the parking spot and then I shut her off to a slight run on and finally off....This is most embarassing because I drop my daughter off at school every morning and all the hot little soccer moms in their Lexus' and Benz's point and snicker at me

She finally starts running okay when I pull back into my driveway

I have NO CLUE what the issues might be and am not in the position now to nutter or change to a different carb or FI....I would just like some possible tips on how th get my mojo back


"The Bannana Channell, Programming With Appeal"....Stay Tuned For a Bunch More!

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post #2 of 10 Old 11-21-2008, 08:09 AM
kmj153
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My jeep does the same thing (1990 with carter carb). I just let it get warmed up and then I drive it.

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post #3 of 10 Old 11-21-2008, 08:15 AM
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It has to be an automatic choke issue. Is the bi-metal coil that operates the chole properly engaged?

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post #4 of 10 Old 11-21-2008, 12:00 PM Thread Starter
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Quote:
Originally Posted by Brown Dog View Post
It has to be an automatic choke issue. Is the bi-metal coil that operates the chole properly engaged?
How do I tell?....It moves freely by hand, but I'm not sure if it is acting properly during warm-up.

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post #5 of 10 Old 11-21-2008, 12:07 PM
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I second the choke diagnosis, but it could be a thermostat problem If the thermostat is stuck open, the engine will take forever to warm up. This happened on my 1986 Toyota 22R engine. Ran like crap for more than 20 minutes and never warmed up in the winter.

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post #6 of 10 Old 11-21-2008, 12:16 PM
jbolty
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Check the manifold heater too.

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post #7 of 10 Old 11-21-2008, 06:44 PM Thread Starter
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Quote:
Originally Posted by ritjobbie View Post
I second the choke diagnosis, but it could be a thermostat problem If the thermostat is stuck open, the engine will take forever to warm up. This happened on my 1986 Toyota 22R engine. Ran like crap for more than 20 minutes and never warmed up in the winter.
I bought a new thermostat a couple of weeks ago and have'nt had a chance to install it....I'm gonna do it this weekend.

I'm also gonna check the manifold heater and choke as suggested (thanks)....Any other ideas?


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post #8 of 10 Old 11-22-2008, 07:36 PM
jay-h
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this is not normal It should work well cold.

With the engine dead cold in the morning, remove the air cleaner look to see that the choke valve is (lightly) closed. when the engine warms up it should be fully open.

Be sure the hot air duct hose is in place from the exhause manifold up to the air cleaner. Make sure the flapper valve on the air intake snorkel moves when the engine starts cold to draw air through the hot air duct.

There are two important sensors, one on the air cleaner houseing, one by the intake manifold (see the sprynet link in the faq to find thes). Be sure they are both working as they should.
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post #9 of 10 Old 11-22-2008, 07:48 PM Thread Starter
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Quote:
Originally Posted by jay-h View Post
this is not normal It should work well cold.

With the engine dead cold in the morning, remove the air cleaner look to see that the choke valve is (lightly) closed. when the engine warms up it should be fully open.

Be sure the hot air duct hose is in place from the exhause manifold up to the air cleaner. Make sure the flapper valve on the air intake snorkel moves when the engine starts cold to draw air through the hot air duct.

There are two important sensors, one on the air cleaner houseing, one by the intake manifold (see the sprynet link in the faq to find thes). Be sure they are both working as they should.
That could be another issue....I don't have the tube from the manifold to the air cleaner. Thanks!

"The Bannana Channell, Programming With Appeal"....Stay Tuned For a Bunch More!
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post #10 of 10 Old 11-24-2008, 10:56 PM
lclark2074
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can anyone tell me ware the elect for the choke is fed forum? my choke is not getting no power to heat up element it is a 4.2L with a carb
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