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Discussion Starter #1
1983 Dodge Ram D150 318 2bbl auto
Mileage guestimation
50,000 on the motor/trany Carb might be original, if so then I don't know on that.
Driving weather = Texas (Where you can deice in the morning and get a tan in the afternoon)

I'm having some trouble with cold starting and running in general in the cold that I need some help with.

Usually when it's cold outside she'll start up fine on the initial start but it takes about 30 min of idling before she will run smooth and wont try to die on me. I've noticed also in the cold when I put her in gear then back into park it wont go back into the full idle speed (some times). Just sounds like she's barely getting enough gas to stay running.

Today for example was the worst day. I started her and let her warm up for about 10 minutes but when I left I got about a mile and she died when I was coming to a stop and would not restart. I had to walk back in the freezing cold and wait for someone to give me a tow, Even after sitting for 2 hours it would not restart. I haven't messed with it since but i bet in the morning she'll fire right up. If I let her idle for about half an hour she will drive fine I just was in a hurry to get somewhere. Lesson learned I guess. heh

What I'm trying to find out is is this normal for a carbureted vehicle in cold weather?

I've never had anything with a carburetor before so im a little in the dark in that area.

When it's warm outside she runs like a top.

I've read in a few posts about some sort of cut off valve that is in the breather that allows the carb to heat up from the exhaust heat so i'm going to have a look at that tomorrow.

Wondering if anyone had some other ideas as what to check out in the morning.

Thanks to all.
 

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I'd suspect your biggest problem is that the intake manifold crossover is plugged with carbon. The damper valve on the exhaust manifold is probably also stuck in the open position. That's a typical small block problem. You have to remove the intake and literally grind and chip the carbon from inside the manifold, and you have to free the damper so it pivots when the truck warms up. These problems are exacerbated by carbs with electric-assisted choke opening.

You can check for the problem by starting the truck, then feel the surface of the intake just in front of the carb. If it's operating properly, you will begin to feel warmth within a few seconds.

Prepare yourself for a nasty, unpleasant job if you have to remove the carbon.
 

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Umm, what do you call cold? Up here in say central alberta my truck fires up so far the coldest at -30c. But occasionaly it idles at near 300rpm then dies... Im not 100% what my problem is thoe.

Cleaning the carbon from the intake is a good idea, you need to take the intake off, chizel and chip the carbon off from the inside of the intake.

Do you have a tac? Do you know what speed yours is idling at?

Also if it is cold enough (once again if your from texas it cant get very cold...) Putting your truck in neutral with the ebrake on will help the tranny warm up.

Also you could have gunk in your carb blocking your fuel. Another problem I had at one time. Check your fuel filter and mabey get a bigger one.

What is your idle speed set at? Try bringing it up a little.
 

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Discussion Starter #4
Thanks for the replys guys.

Umm, what do you call cold?
I should of stipulated that. Usually I have problems with her when the temps below 35-40 or so... Fahrenheit that is.

Do you have a tac? Do you know what speed yours is idling at?
Wish I had a tac so I really have no idea what the idle is.

You can check for the problem by starting the truck, then feel the surface of the intake just in front of the carb. If it's operating properly, you will begin to feel warmth within a few seconds.
I'll have to check this out tomorrow as the truck is all warmed up now.

I must of flooder her good yesterday. She died on me around 2 p.m. Last night I went out there at around 8 p.m. and she still wouldn't start. She'd crank but that's about it. As I suspected in my original post though this morning she fired right up and ran fine all day once I let he idle for about a half an hour.

If it comes down to having to remove the intake I think I'll just wait on it for now. I've been tossing around the idea of either buying a new carb or having a friend of mine rebuild my current one anyway. So, when I tackle that I'll be sure to clean out the intake manifold or just get a new one if it's to bad.
 

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Aka Force Fed Mopar
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Sounds like choke problems, crossover could be clogged also. Make sure the choke off is working properly.
 

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Discussion Starter #6
Sounds like choke problems, crossover could be clogged also. Make sure the choke off is working properly.
I'm guessing the choke is all electric as there is no choke knob in the cab like I've seen on older trucks.

I'm going to buy a book on the truck this Friday, then I'll be able to find myself around the carb more and figure out how to check the choke. Owning previous vehicles that are Fi with gizmos up the wazoo everything's been easy to replace on the truck so far so I haven't really needed a book until now.
 

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Aka Force Fed Mopar
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I meant to say choke pull-off, sorry for the typo.

It's probably a mechanical choke w/ electric assist, meaning it has a heater in it to pull it off quicker. It'll look something like this (not exactly, as this pic is for a Slant 6 choke thermostat)

 

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Discussion Starter #8
Alright I went out and had a look at it just now. After searching the net I think I figured out what and where the choke was. When I take off the breather housing top that plate sitting right in the center of the air filter is the choke plate correct?

With the engine completely cold the plate looks closed. I then started the truck and after about a minute (maybe less) the plate was open. Where it was level with the carb before it now set at a 45 degree angel. Is this the normal operation? (temp outside is 36 degrees right now)

After observing this I decided to pull the truck into the drive to get a better look at it (only a few feet away). When I pulled into the drive and put it back into park it didn't go back into the high idle it usually dose in park. It didn't die just set there idleing really low. (no tac so I can't give any numbers.)

I then turned the truck off and after setting for about 15 minutes I looked at the choke plate and it is still open. I know the idle will be crappy if i start her now so i'll wait a little longer then start it and let her warm up properly.

From what I gather the choke pull-off is the do-hicky that opens the choke? I haven't found that device yet but i'll keep looking.

You can check for the problem by starting the truck, then feel the surface of the intake just in front of the carb. If it's operating properly, you will begin to feel warmth within a few seconds.
I did indeed feel heat on the intake manifold so I'm guessing that the crossover is working properly.
 

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Aka Force Fed Mopar
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Well the intake will get warm even if the crossover is stopped up, just not as hot as if it was open.

The choke pull-off is the vacuum diaphragm on the back of the carb, has a small linkage connecting it to the choke lever. Basically it opens the choke up more when you step on the gas or rev it. If it's not working it can cause drivability problems when cold (aka when the choke is on). It sounds like your choke thermostat is working right.

When did it start this? Did it do it all of a sudden one day, or has it been gradually getting worse?

This what a choke pull off looks like:

 

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Discussion Starter #10
Alright I think I found the problem. While looking at the engine today I noticed a heat shield of some sort surrounding the passenger side exhaust manifold that has an inlet on it of about 2 inches in diameter but nothing hooked up to it. After almost giving up the search I found another inlet on the neck of the breather that is the same size. It's on the underside of the breather neck so that is why I didn't notice it before. On the top side of the neck is some circular device, perhaps a valve with a vacume line running into it. Is this the crossover that suppose to move the exhaust heat to the carb? If so then all I need to do is get the missing hose.

Truck is down right now anyway, starter finally fried. Its been on it's way out for the past six months but finally gave me the bird today.
 

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Aka Force Fed Mopar
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That's the heat riser tube. It would probably improve the cold running in low temperature. I never run one, but I'm in the South too ;)
 

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1986w250
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just to add to speed's last post, the heat riser uses heat from the exhaust manifold to warm the engine faster in cold conditions. one more thing to add, if you do find improper choke operation, you may opt to install a manual choke pull. this allows you to operate the choke as you wish and is easy to install. here in kentucky i usually only have to close the choke if it's below freezing. make sure the choke isn't closing when the engine dies out. it sounds like to me that might be what's going on if it's flooding the cylinders. you might try disconnecting the electronics from the choke you have and tie it open once the engine is warm and simply try to drive it a ways. the way it sounds what might be going on is the engine needs the added fuel when cold, but is actually over fueling as the engine warms. just some ideas, let us know what you find. P.S. is there any way possible you could shoot us some pics to further inform us of what carb is on the truck. not to hurt anyones feelings but we might be able to tell more looking at a pic than what you might be able to tell us. i used to be clueless on carbs, just worked on them alot now. good luck to you.
 

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With the engine completely cold the plate looks closed. I then started the truck and after about a minute (maybe less) the plate was open. Where it was level with the carb before it now set at a 45 degree angel. Is this the normal operation? (temp outside is 36 degrees right now)

From what you've said I believe the pull-off is opening the choke to much.
 

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Aka Force Fed Mopar
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Or, the choke isn't adjusted right. Is the rod from the thermostat bent at all?
 

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Discussion Starter #15
Alright here's an update thus far.

Got the starter on so I'm back in business as far as that goes. Went and got a heat riser tube and put it on. The new tube gets hot and the idle is much stronger while she's warming up. I still gave her about 25 minutes to warm up as I didn't really feel like walking again if it didn't work. I can tell the heat riser tube made a difference but whether it's a fix or a band-aid I don't know yet.

Been misting all week here so this weekend I'm going to take the air cleaner off and get a better look at the choke pull-off if weather permits. I'll try to get a pic of it as well so I can spare y'all from my ******* descriptions like do-hicky and thingamabob. :cool:
 
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