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So I recently inherited my grandads 84 f150. It stalls out at idle unless you keep some pressure on the gas. I've replaced all the ignition parts but the problems still there and it blows black smoke. I think it's the carb but I remember my grandad told me the blower motor caught fire and they had the electrics and wires redone by hand. I take a lot of pride in his truck and I just want it to run right
While there's some quick checks you can make and likely culprits, what you really want to do here is be smart about it. Invest in the '84 Truck shop manual. These are about $30 on CD, a little more in paper book reprint. They contain everything you need to know about specs and Tune-Up. Think of it as a Doctor's physical for a new patient. You want to know exactly what it is that you have to work with, whether there are some "underlying" conditions.
Start with a compression test. Make sure the engine isn't lunched. See that oil pressure is good with a manual gage. If the basic stuff checks out then you can start inspecting the spark plugs, clean out the carburetor, and perform a full Tune-Up. No reason to get ahead of yerself and spend money throwing parts around and spending a lot of time on it if there are major defects, after all this time, who knows what problems lurk?
While there's some quick checks you can make and likely culprits, what you really want to do here is be smart about it. Invest in the '84 Truck shop manual. These are about $30 on CD, a little more in paper book reprint. They contain everything you need to know about specs and Tune-Up. Think of it as a Doctor's physical for a new patient. You want to know exactly what it is that you have to work with, whether it's worth it.
Start with a compression test. Make sure the engine isn't lunched. See that oil pressure is good with a manual gage. If the basic stuff checks out then you can start inspecting the spark plugs, clean out the carburetor, and perform a full Tune-Up. No reason to get ahead of yerself and spend money throwing parts around and spending a lot of time on it if there are major defects, after all this time, who knows?
I'll look in to a compression test.
so far I've replaced the distributor cap, rotor button, ignition coil, spark plugs,fuel filter, fuel pump, and the air filter
I got to ask why does everyone replace the coil as part of the "tune up"?
There should not be a need to ever replace a coil unless it tests bad for no spark.
That was not meant for you as other do it also.
Welcome to FTE
Has the truck been setting for a long time?
I am guessing it has and also guessing the gas in the tank(s) is bad and this could make it not idle.
Also if any gas was left in the carb before it sat the carb could get gummed up inside and be the cause of it not to idle.
Now being a 84 this could have what Ford called a feed back system.
A computer made adjustments to the carb & dist. for timing.
If you pull the air filter are there wires going to the carb?
Is there a vacuum line going to the dist. or a gray little box with a lot of wire going to it?
If you can post a picture of the carb & dist. so we can tell what you have we can then point you in a direction for a fix.
BTW he was lucky he did not loose the whole truck in that fire.
It is "kind of" normal for that to happen but can be prevented.
The fix for that is to find a used HVAC box for AC as your truck has AC and replace it.
I know any 80 - 86 HVAC AC box should work and maybe the 87 - 92 will work but I am 100% sure.
Dave ----
I got to ask was does everyone replace the coil as part of the "tune up"?
There should not be a need to ever replace a coil unless it tests bad for no spark.
That was not meant for you as other do it also.
Welcome to FTE
Has the truck been setting for a long time?
I am guessing it has and also guessing the gas in the tank(s) is bad and this could make it not idle.
Also if any gas was left in the carb before it sat the carb could get gummed up inside and be the cause of it not to idle.
Now being a 84 this could have what Ford called a feed back system.
A computer made adjustments to the carb & dist. for timing.
If you pull the air filter are there wires going to the carb?
Is there a vacuum line going to the dist. or a gray little box with a lot of wire going to it?
If you can post a picture of the carb & dist. so we can tell what you have we can then point you in a direction for a fix.
BTW he was lucky he did not loose the whole truck in that fire.
It is "kind of" normal for that to happen but can be prevented.
The fix for that is to find a used HVAC box for AC as your truck has AC and replace it.
I know any 80 - 86 HVAC AC box should work and maybe the 87 - 92 will work but I am 100% sure.
Dave ----
ps got to love all the red re-wire LOL
yeah the rewire was done by hand by some of my grandads old war buddies. As far as the vacuum lines go I believe most are capped or have a twig shoved in them.there are no wires running from the air filter to the carb. The last time my grandad drove it was about 2 years ago and I dont remember it having this problem then, but I will take pics when I get off work. As far as the ac goes eh, it has those magnificent triangle windows that freeze you just fine
I also should add when you press the accelerator just a hair it's just fine, and there are no hiccups or shudders when driving down the road. It's just when you let off the gas or load the engine up a hill without putting your foot down.
yeah the rewire was done by hand by some of my grandads old war buddies. As far as the vacuum lines go I believe most are capped or have a twig shoved in them.there are no wires running from the air filter to the carb. The last time my grandad drove it was about 2 years ago and I dont remember it having this problem then, but I will take pics when I get off work. As far as the ac goes eh, it has those magnificent triangle windows that freeze you just fine
Twigs used as vacuum plugs love it as long as they are all plugged that is good. Just a FYI there is a vacuum tree under and to the back of the intake manifold and there is a cap or 2 on it. 1 is really down, back and under hard to see / find and this cap always cracks so check back there really good.
The wires don't go from the air filter to carb they would go from the carb to the trucks wiring harness. You will need to remove the air filter to see them. You should have 1 wire going to a black cap on the side of the carb. This is for the choke to help it open as the motor get warm.
If it has been 2 years since it has run the gas can be and I would say is bad and make the motor run like crap at idle.
Depending how much gas is in the tank you may want to drain it out, check the inside of the tank(s) for rust and crud. If bad replace the tank(s) & senders.
It may not be a bad ideal to replace all the rubber hoses from the tank(s) to the carb. Over time they dry out and crack and / or break down on the inside and plug the line or carb.
If there is not a lot of gas in the tank(s) see about running them dry and then put fresh gas in. Could also add a can of Sea Foam to clean the fuel system & carb.
If you want, run a hose from the fuel pump on the motor to a gas can on the fender to see if it runs better on good gas. Could also add some Sea Foam to it to help clean the carb.
Originally Posted by Zoaz123
I also should add when you press the accelerator just a hair it's just fine, and there are no hiccups or shudders when driving down the road. It's just when you let off the gas or load the engine up a hill without putting your foot down.
I know for a fact the electric choke doesn't work. But I've let the engine warm to operating temp and it still floods/chokes out.
Ah, that may 'splain a lot. Most electric chokes require power to open for normal driving. Remove the power and the choke slowly reverts to the closed position for the next cold start.
Run the engine to normal operating temperature and shut it off briefly to remove the air cleaner lid. Start the engine again and look at the choke plate. It should be fully open. If closed, the engine will run extremely rich.
I don't know why I am the only one that jumps on this all the time. With all that stuff plugged off and disconnected, that engine will never be "right". Your timing is locked at whatever the initial was set at with the timing light whenever that was. The timing is not going to be advanced properly, hurting fuel mileage and power.
Yes you can get it to run like that, but your mileage and power will be way down. The reason I always bring this up in the beginning, if you are contemplating getting a new carb and some other things, now is the time to decide what direction you are going to go in. I think you have 3 main directions you could pursue;
1. Leave it like it is, find the flooding problem and then have a very handicapped engine on your hands.
2. Repair it and all the sensors, the vacuum hoses and wires that are missing to the throttle position sensor, the MAP sensor, the engine temp sensor, etc. This would take a lot of diagrams and manuals, and a lot of studying to bone up on how this was all hooked up. When it worked, it worked well. You have to pull codes on it, just like a fuel injected engine.
3. Revert back to a simpler setup. This would involve getting a older carb (you can get these pretty cheap on ebay and Amazon now) and get a older type distributor system that will handle the timing properly. You can use the old Ford duraspark II system or use a aftermarket HEI distributor.
I don't know why I am the only one that jumps on this all the time. With all that stuff plugged off and disconnected, that engine will never be "right". Your timing is locked at whatever the initial was set at with the timing light whenever that was. The timing is not going to be advanced properly, hurting fuel mileage and power.
Yes you can get it to run like that, but your mileage and power will be way down. The reason I always bring this up in the beginning, if you are contemplating getting a new carb and some other things, now is the time to decide what direction you are going to go in. I think you have 3 main directions you could pursue;
1. Leave it like it is, find the flooding problem and then have a very handicapped engine on your hands.
2. Repair it and all the sensors, the vacuum hoses and wires that are missing to the throttle position sensor, the MAP sensor, the engine temp sensor, etc. This would take a lot of diagrams and manuals, and a lot of studying to bone up on how this was all hooked up. When it worked, it worked well. You have to pull codes on it, just like a fuel injected engine.
3. Revert back to a simpler setup. This would involve getting a older carb (you can get these pretty cheap on ebay and Amazon now) and get a older type distributor system that will handle the timing properly. You can use the old Ford duraspark II system or use a aftermarket HEI distributor.
there isnt anywhere to pull codes from as far as I've seen. I haven't even seen a computer module
Look under the dash, right over the tranny hump on the firewall. Should be a large silver box with lots of wires going to it. If it's not there, someone may have taken it out. If they went to all that trouble, they may have already converted it over. Do you have a vacuum line going to your distributor? Or does it have a rectangle looking module bolted to the side of it?
Look under the dash, right over the tranny hump on the firewall. Should be a large silver box with lots of wires going to it. If it's not there, someone may have taken it out. If they went to all that trouble, they may have already converted it over. Do you have a vacuum line going to your distributor? Or does it have a rectangle looking module bolted to the side of it?
Some people keep that, even though they use the other stuff to convert it over. See if you have a plastic module mounted directly to the side of the distributor. I know your truck originally had this stuff, we just have to figure out what state you are in now.
Some people keep that, even though they use the other stuff to convert it over. See if you have a plastic module mounted directly to the side of the distributor. I know your truck originally had this stuff, we just have to figure out what state you are in now.
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as long as they are all plugged that is good. Just a FYI there is a vacuum tree under and to the back of the intake manifold and there is a cap or 2 on it. 1 is really down, back and under hard to see / find and this cap always cracks so check back there really good.
