Engine dies when warmed up

[wreckless17]

78 chieftain needs help the sheriff wants to tow it if I don't move it but it won't go it will start when cold but once it warms up it dies had carb rebuilt again same thing it dies still changed plugs cap rotor ballast resistor ignition control module checked all the wires one was burnt and had rip in it replaced it still same issue I'm running low on time any ideas

[LJ-TJ]

Just a thought but I had a similar situation and it was the coil. As the coil got hot it would brake down and the engine would quite. Just a thought. Oh! and the crazy thing is it was a brand new coil. Don't think that wasn't a trouble shooting nightmare. D:oH!

[wreckless17]

Had same thought as well bought one of those accel coils and a bwd  one no luck thank you I'm starting to get worried and don't have enough money left for tow truck

[GONMAD]

Join Good Sam's for the premium package for I think $178.00 for towing ANYTHING ANYWHERE up to 100 miles a day. Some people I met moved from Ohio to Florida one day at a time till they made it.No problems from GS. I recently did this move for a Bounder 40 miles away. The towing was almost $700.00 regular, but joining GS it stayed at the registration fee. Just a suggestion guy's. Hope you don't lose your rig.                GONMAD

[wreckless17]

But my issue is I only need to go 2 blocks but I'm on this steep incline and I have aaa with rv towing but I used all my tows I've pulled this thing with my truck but never on this big hill

[Lefty]

A gasoline engine (any gasoline engine) is rather simple in what it needs to run.. So let's break this down a bit for you.
It has to have air and fuel that is fairly atomized and at a ratio around 15 parts air to 1 part fuel (15:1). It needs air and fuel in around 15 parts air to 1 part fuel, that is fairly well atomized and mixed. It needs a spark, at around 8 deg BTDC (before Top Dead Center) of the compression stroke. It needs enough compression to compress the air & fuel at least 7 to 1. (regular gasoline bare minimum to start and run.) And finally, it needs a way to get rid of the burnt gases so it can do it all over again.

Since your rig will start up and run when cold.. We can eliminate compression You obviously have enough compression to start, and engines typically don't lose compression after they warm up. So I doubt it's a compression issue.
Likewise, we can eliminate the timing as an issue. If your timing was off enough for it to quit when warm, I highly doubt it would start when cold.
It's getting enough fuel to start.. have you tried to spray starting fluid into the carb AFTER it has quit when warm? If it will then start back up and run on the starting fluid, you may have a weak or bad fuel pump, or other fuel supply issue. Possibly a clogged fuel line or filter, clogged fuel strainer in the tank, or clogged jets or idle circuit in the carb.
It's firing when cold, but have you verified it is still firing when the engine has quit when warm? A bad coil winding, bad coil resistor, or bad ignition system component (ballast resistor, electronic control module, or even a bad switch in the steering column or wiring.can all fail after they get warm but work when cold.
A clogged exhaust can be from a collapsed muffler. This can, in extreme cases, restrict the exhaust flow enough to cause the engine to stop running after it has ran a few moments. You should be able to feel a strong flow from the tailpipe with it idling. If it feels weak, try disconnecting the exhaust at the engine manifolds temporarily to see if the problem goes away.

Worst case.. You said it will crank when cold... and you only need to go 2 blocks. you should be able to start it and throw it in Drive and take off..It shouldn't be even slightly warm after only 2 blocks. Even if you only get part way, have to let it cool off, and get the rest of the way.. You should be able to move it only 2 blocks.

[Rickf1985]

It sounds like it is running until the choke goes off and then it leans out. Like Lefty said, Start it and make a run for it right away. You will not hurt anything. One thought, when you stomp on the gas does it pick up right away or die out? If it dies out then the accelerator pump is probably not working. I know you say it was rebuilt but was it done correctly and were all of the jets cleaned correctly? If the accelerator pump is bad then it will be a challenge but if you slowly add more and more gas pedal to it then it will move eventually. Just don't hit the pedal fast or it will stall.

[76minnie]

This might be a stupid question, but did you have this issue before you parked on the steep hill? Maybe fuel pump is weak?

[Rickf1985]

I have been assuming you have enough gas in it. Being on a hill the gas could be running away from the pick up. Anything above a quarter tank should be good.

[wreckless17]

lefty any time u step on the gas it also dies it will run for a second when warm then cut out i had the guy from the shop that rebuilt the carb again come and check it out and he said its runnin way to lean so he took the carb off and back to the shop to fix it again. i was thinking vacuum leak but he couldnt find one when it was running while cold so right now im waiting for him to return with carb i just hope he returns before the sheriff cuz last nite they said i have one more day til they are gonna tow it

[wreckless17]

no i wasnt trying to park there thats where it died

[Lefty]

If it's running way lean, it could be as supply issue (not enough pressure or volume from pump), or it could be a vacuum leak (spray starting fluid around the base of the carb and on the vacuum lines, and around the intake manifold gasket flanges (especially the front & rear corners).. if it revs up, there is your leak.
It could be a bad or improperly adjusted accelerator pump, or a clogged circuit in the carb itself too.
Timing advance may not be working, they are bad about seizing up from disuse..try removing the cap & rotor and manually twisting the timing advance plate by hand.. if you cant throw the weights out, it's frozen up.
Good luck.

[Rickf1985]

The timing shouldn't affect it to the point of dying like that. Low power but not cutting out. I am leaning towards a bad rebuild with a clogged main or bad accelerator pump. I would think that the Sheriff should cut you some slack as long as you are actively working to get it moved unless it has sat there for a long time and you are just now getting to it after many notices. If your guy is a professional mechanic he should be able to pin this down with no real problem, it is the same engine as any other vehicle and it is a lot easier to diagnose when you are right there looking at it than it is over the internet. We can give a hundred scenarios but we are not getting real time feedback and we also cannot hear it running and dying.

[wreckless17]

Well they rebuilt the carb again they said it was a jet clogged by some sort of adhesive they used to seal part of the resin body of the thermo quad so it starts up goes into drive I'm driving up the hill and it feels like it's gonna die out til I take my foot off the gas so it barely makes it home now I'm thinking what's wrong now  thank you for your advice Its all greatly appreciated

[Rickf1985]

You need a new rebuilder...................... and a new carb.

[tiinytina]

and a new gas cap..... maybe.... as there is a vent in it which can and does fail over time :-). 

And I'm sorry if they are admitting to what the problem "might" be... they should in the same sentence be saying... and we will gladly rebuild it again for FREE.... in a perfect world. 

[Rickf1985]

I am guessing that if they had to seal a part of the resin body then it is cracked or broken and needs to be replaced. I know JB Weld is "supposed" to stand up to gasoline but I have not had any success with that. It breaks down in a month or so. Possibly due to the alcohol in the gas. From the sound of it they used something like a gasket sealer which just fell apart.

[wreckless17]

they did rebuild it and got me a used resin body but they charged another 30 bucks for it.  it still doesn't run right like i feels like its always about to run out of gas

[Rickf1985]

That could be caused by many different things. You would have to go through a complete checklist in proper order so as to eliminate things in an order that will keep unnecessary parts replacement to a minimum. You really need to find a different mechanic, no way should he have charged you a second time on that carburetor. It was his fault he did not fix it right the first time. I have seen many people here mention many things that could be causing your problem and they are all right. But it has to be done in the right order.

[RANGERRICK]

Did you check the electrical connection for the ignition switch under the dash,it should be the flat connector with a bunch of wires?

[LJ-TJ]

Man I feel your frustration. I went through a similar situation with my 318. No I'm not going to tell you how I finally fix it. But I'm sure you can guess around $2000.00. You have many here feeling your frustration. D:oH!

[Bennett77]

You can get a carb for the 440 from AutoZone, I know because that was one of the first thing I did once I got my unit home. DO not depend on a local shop to rebuild a Thermo Quad. I am not promoting any company, I shop every supplier near me for parts. Some have them others don't, If you don't fine the part at one you may find it at another.

[Rickf1985]

I am not a fan of the big box auto parts stores. You will not get a quality rebuilt carb there. They buy there parts from the cheapest places they can get them, that is how they can sell parts cheap. If you want a quality rebuilt carb you are going to have to go to a specialty carburetor rebuild shop. You will pay a little more but you will get a basically new carburetor and you can usually get performance upgrades if you want them. Carburetors were my specialty when I had a shop, I do not do them as a business anymore because most of the cores I see are worn out. The bigger shops can afford to buy hundreds of cores and that way they get good ones. the more popular carbs like Quadrajets are still being made new by aftermarket companies.

[Oz]

If you want a like-new, quality, re-built carb.  Call these guys in Pinellas Park, FL.  I lived a mile away.  They're good old fellas who really know what they're doing and have every carb imaginable at very reasonable prices:


http://www.guaranteedcarburetors.com/


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Our Lifetime Warranty guarantees years of dependable operation and our customer service is always available either online or by toll free phone; 1-800-250-8746

Guaranteed Carburetors pays for you to return the old core anywhere in the continental United States.
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Repack your core in the box that your carburetor came in, adhere the UPS label, and give to any UPS driver or UPS drop box.

No paper work or long lines and it's FREE!

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If that doesn't pique you interest, I don't of anything better that will -

[Rick Shaw]

Had the same problem with my Winnie.   It would idle nicely but when I stepped on the gas....it would cut out.   Come to find out it was a clogged fuel filter back under the frame.  All you have to do is follow the fuel line and it will be there.   It was a common problem with old Winnies.   The gas tank develops crap and it makes its way to the filter and clogs it.   The pressure when stepping on the gas pedal brings all that crap out of the tank and into the filter.  The fix is to have the gas tank dropped and cleaned or a new gas tank installed.  A way to beat this is to keep a full tank of gas and not let it get down to where it is sucking all of that crap off the bottom of the tank.   It was a cheap and easy fix just replacing the filter....but it is something that you have to keep doing....all you do is carry an extra filter.   I have had to change mine on the side of the highway many times.