1984 Chieftain runs for 30 seconds then dies.

[JackieBoy]

I got a 1984 Chieftain 22 footer from my grandparents when they passed away. This vehicle is spotless with 0 chewed wires from mice and has been under covered storage its entire life. I have done a lot to try to get it up and running however I am in way over my head feels like.

The problem here is that the engine (Chevy 454 8,cyliner) will start up and run for about 30 seconds then dies. before I even turned the key for the first time I made sure to replace the in line fuel filter, the mechanical fuel pump at the front passenger side that is attached to the engine, and I dropped the fuel tank and replaced all the lines to the sending unit and didn't replace the sending unit as it was in good condition. Then I put fresh gas in and tried to get here going. (also flushed the radiator and replaced the old fluid with the new)

started up after the fuel got to the engine but will slow down rpm rapidly after 30 sec and dies.

the distributor cap look's fine and the spark plugs look great. Well maintained vehicle with only 53,000 miles on it. I am at a loss as to why it wont keep running. New batteries and all so its all juiced up. If someone knows of any part that I need to check out please hold my hand and show me the way.

[Morich]

Some ideas but I will need a refresher on what is under the hood on that age group!
I think that will have a carb? Not fuel injected?
Points under the lid on the distributer?
A great big filter housing on top of the carb?
If that part is right, you may be in luck ! Those were the days when the mortal man could still fix things on an engine!

You've done some good things but there may be some simple things to check further.
It takes fuel, air, and fire to run an engine, so some checks on making sure each is there may be a first check?
If it starts and runs and the fuel filter is good, you may have that covered.
How about air? Have you taken the cover off the filter and made sure it is okay? There are times when an RV is stored and things like birds, chipmunks or ground squirrels move in and build a nest in the filter housing! that can mess up the air supply!
One way to assure an engine can get all the air it needs is to take the filter off the carb and test run it! It should run normal without the filter, etc. as that only keeps us from sucking in bugs or road junk!

While in there, look for some form of choke system. Maybe a set of connections that move a flap open/closed to adjust how much air goes down the carb throat until it warms? You may be getting fuel and air but the mixture has to be somewhat correct as well. If too much or too little fuel, the engine can gradually get further and further from the "right" mix and gradually die!

I have never been a Chevy guy and much of what I knew is no longer made, so finding a repair manual like a Chilton's would be ideal.
Maybe check the local library for a hard copy or consider buying one from a local parts shop? They would have a vast amount of really good info that is far more reliable than my advise!
There is the question of the plugs firing and that is way past what I remember well enough to count!

Possibly contact with a local truck/car club would find some good folks who know it well? I always tried to let my brother do the thinking!

It sounds like a good one but it may take some fussing to get it right!

EDIT?
A point to check before going too far on the chassis repair. Be aware that RV may be built on a chassis which can be a year older.
An 84 may be on a 83 chassis so for parts, repair of the chassis, look for a label next to the driver's side where it will list a bunch of good info like build dates and model, etc.
Got the owner's manual?
https://www.winnebago.com/Files/File...ago-Itasca.pdf

[bigb]

Check for a big vacuum leak (pull and cap the hose to the brake booster in case the diaphragm is broke). Also if that has a Rochester Quadrajet there is a small filter that is spring loaded right where the fuel line attaches to the carb inside that threaded cylindrical part. The spring allows fuel to push past it if clogged but at idle there may not be enough pressure. Be careful with the carb threads as they are easily stripped.

[Ray,IN]

Originally Posted by bigb

Check for a big vacuum leak (pull and cap the hose to the brake booster in case the diaphragm is broke). Also if that has a Rochester Quadrajet there is a small filter that is spring loaded right where the fuel line attaches to the carb inside that threaded cylindrical part. The spring allows fuel to push past it if clogged but at idle there may not be enough pressure. Be careful with the carb threads as they are easily stripped.

I've seen that check-ball so gummed up from evaporated gas it couldn't move, so had to remove and clean things with carb cleaner.

[JackieBoy]

I have found a bunch of hoses that need to be replaced so hopefully that fixes the vacuum leak you are referring to. As far as the diaphragm to the break booster I’m not exactly sure what you are referring to. It does say Rochester Quadrajet I’ll see if there is a blockage in the line

[bigb]

Originally Posted by JackieBoy

I have found a bunch of hoses that need to be replaced so hopefully that fixes the vacuum leak you are referring to. As far as the diaphragm to the break booster I’m not exactly sure what you are referring to. It does say Rochester Quadrajet I’ll see if there is a blockage in the line

There is a large vacuum hose going from the intake to the brake booster. There is a diaphragm inside the brake booster, if has a hole in it this will be a large vacuum leak.

[JackieBoy]

Thank you for all that information. The carburetor looks good no junk in there. I’ve been trying to use carb cleaner and free up any linkages so hopefully it all works out. Off to Napa for some new vacuum hoses

[JackieBoy]

So I’ve been replacing all the lines that are marked that are damaged hopefully that will help. Also what looks like a fuel line (marked in yellow paint) is loose to the touch. Can slide up and down easily where as the other line to the left of it is snug. I’ll take a video of it running after I replace some more hoses. Hopefully I can post a video here I’m not to sure though.

[bigb]

That line marked with yellow paint is a hot air tube for the automatic choke. One line draws air into the recess where it picks up heat then it is drawn into the choke housing to expand the coil spring and open the choke as the engine heats up. It is all connected to and part of the engine vacuum system.

[Morich]

Okay, if no book on hand, some things come back in memory! Long time no see?
There are some points that may help. One in the top picture is what I think will be like the idle adjustment! Find another screw like this that moves with the gas pedal moving?
If the engine is running a bit too slow when idle, it may slowly die. Find the correct adjustment screw, when somebody pushes the gas pedal, this screw adjustment will move as the engine speeds up to ID the correct adjustment.
Until you get better training (!) I might not want to change the other adjustments just yet!
But the idle speed is not one that you are likely to get too far off without knowing it. If you study it a bit, you may see that turning the screw in will hold the throttle open just a bit when you let off the gas! Sometimes the idle just gets too slow and small turn can make it idle a bit better?


But for the stalling? When the engine is running and as it warms, that metal plate should open up as the engine warms. It is connected to a spring inside the round "knob" looking thing in the top picture. Warm air goes in, the spring moves and should open the plate to let more air in with the gas!
What you may want to look for is this sticking?? Move it with a finger or something and feel the spring want to move it back if it is cold. This was a big "NEW" idea at one time. Before that we had to manually pull a knob to choke the engine to get it to start when cold! Just starting the engine took some talent to get the right fuel and air mix to burn!

But this may be involved with why it runs for a bit and then dies. If the coke is on like I see it now and the engine start, the choke stuck closed or not opening soon enough can make the fuel mix too high and too much fuel with too little air won't burn!
With that in mind, if it comes up, make sure the plates are moving as the engine warms, and it may help the engine run if you give it more air.
That takes loosening the screws holding the ring on the round choke body, turning it slightly and then tighten the ring to hold the setting!

Way different than current engines. The biggie is that we could get enough training to be able to look, find and fix a problem, even though it came up much more often.
Now we have to take a lot of stuff in as we can't see and they tie it to a machine to tell them what parts to throw out!

We don't have to do it nearly as often but it costs a tub more when we do! When the machine fails to get it right, they may not have any idea what to do and we have to trade cars to get out of it!

[JackieBoy]

Originally Posted by Morich

Okay, if no book on hand, some things come back in memory! Long time no see?
There are some points that may help. One in the top picture is what I think will be like the idle adjustment! Find another screw like this that moves with the gas pedal moving?
If the engine is running a bit too slow when idle, it may slowly die. Find the correct adjustment screw, when somebody pushes the gas pedal, this screw adjustment will move as the engine speeds up to ID the correct adjustment.
Until you get better training (!) I might not want to change the other adjustments just yet!
But the idle speed is not one that you are likely to get too far off without knowing it. If you study it a bit, you may see that turning the screw in will hold the throttle open just a bit when you let off the gas! Sometimes the idle just gets too slow and small turn can make it idle a bit better?
Attachment 189872

But for the stalling? When the engine is running and as it warms, that metal plate should open up as the engine warms. It is connected to a spring inside the round "knob" looking thing in the top picture. Warm air goes in, the spring moves and should open the plate to let more air in with the gas!
What you may want to look for is this sticking?? Move it with a finger or something and feel the spring want to move it back if it is cold. This was a big "NEW" idea at one time. Before that we had to manually pull a knob to choke the engine to get it to start when cold! Just starting the engine took some talent to get the right fuel and air mix to burn!

But this may be involved with why it runs for a bit and then dies. If the coke is on like I see it now and the engine start, the choke stuck closed or not opening soon enough can make the fuel mix too high and too much fuel with too little air won't burn!
With that in mind, if it comes up, make sure the plates are moving as the engine warms, and it may help the engine run if you give it more air.
That takes loosening the screws holding the ring on the round choke body, turning it slightly and then tighten the ring to hold the setting!

Way different than current engines. The biggie is that we could get enough training to be able to look, find and fix a problem, even though it came up much more often.
Now we have to take a lot of stuff in as we can't see and they tie it to a machine to tell them what parts to throw out!

We don't have to do it nearly as often but it costs a tub more when we do! When the machine fails to get it right, they may not have any idea what to do and we have to trade cars to get out of it!

Yeah long time no see been in and out of repairing and moving a lot of furniture around lately. The metal flaps do open when the engine is running and you can see directly in there. It does have a low idle seams like I can increase that. I have tuned chainsaws before so I feel good about doing this. No repair manual around locally I did see the manual from Winnebago I’ll print that one out. I am in the process of trying to unscrew the main fuel line to the part that says (filter) to see if it is gummed up with old fuel. Like the last post was talking about. It’s really stuck and I’m getting close to rounding off the nut to the fuel line so I’m not trying to be to aggressive with it anymore.

[JackieBoy]

Filter, formally known as Excalibur.

[bigb]

Originally Posted by JackieBoy

Filter, formally known as Excalibur.

You'll want to remove the fuel line first. Spray the threads on the filter housing with solvent and maybe tap tap tap in both directions, be patient and soak repeatedly. I don't remember if the carb has flat spots there but if it does put a wrench on the flat spots and another on the filter in such a way that by squeezing them together with your hand it will loosen. Be careful if only using one wrench as you could break the casting on the carb.

[Morich]

Did not mean I had not seen you in a while.
What I meant was how long it had been since I had taken a good look at a carb! That means my memory is to be checked before trusting!

[JackieBoy]

I am using both wrenches. It looks like there is plumbers tape in the threading of the fuel line. I’ll try the solvent soak method it seams pretty stuck at the moment.

[bigb]

A set of line wrenches is indispensable for fuel lines

[JackieBoy]

At Napa now shall pick some of these up. Chewing up that nut pretty good seams like it’s aluminum. That plumbers tape in the threads are not helping.

[bigb]

That's a flare fit and there is no need to use thread tape on it, in fact thread tape could hinder proper tightening.

[JackieBoy]

I agree no need for the tape someone else put that there. Still trying to get it loose. I have been putting blaster penetration liquid that “breaks free rusted or frozen parts” and been going after it with a slight tapping to work the liquid in there for a few hours. Still stuck will keep at it. There is a video on YouTube of a guy taking this apart fairly easily but then again his engine is suspended in the air not attached to anything. Besides the stand it rests on.

[bigb]

Some people swear by a 50:50 mix of acetone and transmission fluid, never tried it personally though.