peanut2001, Did the tune-up help your truck any? What parts have you replaced?

 

Ok I have repalced plugs, wires, cap, rotor, fuel, filter.
I also ran the VIN number and the "Y" tells me that it is a 360 not a 390 like i was told.
That is ok W/me I just am happy to know. I also have put a timing light to it and set it at 10* BTC at around 1000rpms.
I also checked the two fuel mixture screws and they were both 7 and 8 turns out. Im sure this wasnt right so i set them at 1 and a half turns out and things didnt seem to change much.
Actually I believe things may be worse now. it now will be idling along fine and just when i think that sounds good , the bottom would fall out of it and it would just die, and i would have to hold it to the floor and crank it till it started and clear its throat hard and it would idle again for awhile then just fall out again. It acts like its flooding or something.
I took it down the road and the performance diddnt seem to be there on acceleration and it was dieng at stops. The idle seems to really be dropping out in gear more than i expected and it dies. Ive ordered a new remanufactured carb and plan to repalace all vacume lines. any thoughts or other suggestions please givvum i purchaced this truck sunday and havn't been able to enjoy it

 

When setting the air fuel mixture screw on your carb. Start with each mixture screw at 1 1/2 turn out (counter clockwise rotatione) as Uncle Mil1ion mentioned, then with the engine running, turn out each mixture screw out 1/4 turn, making sure each mixture screw is turned out evenly (such as 2 1/2 turns,or 3 1/4 turn). If you lose count on the mixture screws, start over again. Most likely, you will need to raise or lower the engine idle on carburator idle screw during this process.


Your title is correct, September (9/74) is the date the MVD willl consider as a years changed on any vehicle, meaning it will be considered a 1975 year.

 

thanks, In screwing in and out the screws on my old carb nothing seemed to change as for as idle or anything. And I noticed while gassing it up i could see fuel spraying from the top of the carb a little bit. i really think it was over fueling. also im a bit confused abut the workings of and possibly the problems of that electric choke i believe it is, may be causing, because i really dont know if there is anything to set on it or not or if it is really needed to set the carb up. it wasn,t plugged in and the copper tube from it is broke loose from the manifold or at least i think that is where it goes. could you let me know anything about it or if it may be part of the problem or shoiuld i just leave it unhooked to set up my new carb.
Do you think im making a good move to buy a new carb or am i jumping the gun. I hope it does the trick cause if not im outa ideas.

 

Fuel spraying from the top of carb is a carb problem, and is related to the needle and seat getting a contaminate or the floats in the carb getting saturated with gas or out of adjustment. This will require loosen and removing the top metal cover of the carb, to expose the needle and float assembly. Most times the gasket at the base of metal cover will break and will not be reusable. Then it will require a carb kit to repair.

 

I have already ordered the carb it will be in tomorrow. It is a original rebuild from advanced auto and i get the feeling it will only be the carb. and no choke and i will have to jump all my parts from old choke assembly to the new carb.
And now its worrying me that the choke not functioning properly may be part of my problem heck i dont know. mabey i should just not hook the old choke back up to it and see how it runs without it. and then hook it up see how it runs with it and if its not right then order new choke assembly.
The carb i am replacing is a factory rebuild also and it has an electric choke but the wire was not hooked up and it still had the metal tube hanging there. mabey the previous owner just let it hang. what do you think about just hooking the carb up and not the choke assembly or will that create more problems?

 

That carb is toast and the PO was trying everything illogical to make it better I suppose.

You asked for a starting point fot eh idle mixture screws.
I gave you the starting point, Usually they end up between 2 1/2 & 3 turns out.

Get yourself a vacuum test gauge for making this adjustment. They work great !

You will need to change the idle speed occasionally to set the mixture correctly.

Make sure you do all these adjustments after you have set the mechanical things like:
Timing
Choke position
Verified that the Vacuum Advance is free & working
The accelerator rod is set at the proper indent on the carb.
All Vacuum Hoses ON
New Fuel filter installed.
New air filter with Air cleaner asembly ON
Engine at Normal operating temp with Choke OFF (top butterfly fully open)


Remember :

It is best to hook everything up the way Ford intended.

You can run a wire from the choke to the Stator terminal of the alternator.
This allows power to the choke only when the engine is running.

 

thank you you have been a big help. Something you said in your last post rung a bell.
The top butterfly was never running fully open during my working on it yesterday and the engine was at full temp. Actually i would sayat idle it was running3/4 closed.
Also im not sure what to do w/ the vacume guage. I will pick one up today. where do i hook it and what am i looking for and does the idle mixture screws change the vacume? I also need any tips on how to set choke position and how to make sure vacume advance is working proper. Im sounding pretty ignorant now but im feeling that way also.
Thanks again

 

First off there are parts stores that have a "Lend-a-tool" program.
This allows people to have free use of specialty tools.

1) Checking the Vacuum advance !

Requires a Vacuum Tool.

Inside the distributor you will see the vacuum advance arm attach to the silver advance plate.You can attach the vacuum tool to the port and create vacuum to pull on the arm.Watch the arm as you do this.

If it doesn't move !

You need to get into the distributor and remove the spring clip that holds the vacuum advance arm to the advance plate.

Try applying vacuum again.

If it now pulls measure how much vacuum it took to move it.

Write that down and post it here in this thread.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

2) Choke adjustment.

I will look up the choke adjustment and post it here for you.

The term indexing the choke wil become self-evident when turning the choke housing to the correct mark.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3) Vacuum gauge.

The use of this is to determine the smoothest running of the engine.
Watching the gauge needle while turning the mixture screws will help you determine
the proper setting of the mizture screws.

 

ok the new carb is on and things are looking up. I installed the carb as it came outa the box battled a bit to get it running but it finally did and i set the main idle screw till it would idle by its self. then checked the timing. I removed and plugged the vacume line from the distributer. this dropped the idle a bit but still kept it running. then i set the idle too 750 and set the timing to about 8 BTC then repaced the vacume line and the RPMs came up to about 1100 so i backed it back down to about 950-1000 and left it there. When i put it in gear it goes from about 1000 to 600-700 this seemed about right.
So i took her down the road and it seemed real good just a very slight hesatant on a fairly quick aceleration but ok. I havent messed with the fuel mixture screws at all kinda afraid too. i may let a more qualified person fool with them i dunno.
I did try a small burn out brake torque to check power and no way it was even going to think abouit it. It diddnt die or anything but just wouldnt bring the rpms up. i dunno if it should or not but it diddnt. mabey some fine tuning and it will be fine.
Let me know your thoughts, youve been a big help this far

 

Try adjusting the fuel mixture screws your self first, if it don't stay right, then you can pay someone to do it. If this doesn't work, then try the vacuum method uncle Mil1ion mentioned.

 

ok i will try it tomorrow and let you know how it goes. Did the timing method and final setting sound about right to you that i did?

 

What do you think about the engine power i described should it be more than this or not? Should it turn the tires or not be able to bring the rpms up enough. It really doesnt matter im not looking for a hot rod i just want it to have all the power and run the best it can. but i thought it should be able to turn the tires. Will the mixture screws make much differince in this department?

 

Set the idle at 750 in Drive.

Here's an article you can read.

http://home.earthlink.net/~bubbaf250...b/carb02b.html

Another way is the "On The road" way of adjusting the screws..

This way is to turn them "rough idle to rough idle" then split the diffeence.

This means:
From the 1 1/2 turns out setting >>>>>Turn one screw at a time clockwise until the engine starts to run rough....then turn that screw counter-clockwise (Counting the turns you make) until the engine starts to run rough.

EXAMPLE only:
If the screw was turned counter-clockwise exactly 3 turns ...divide that in half.... and turn the screw back clockwise 1 1/2 turns.


Now do the same for the other screw.

 

The vacuum advance on the distributor is getting direct vacuum and should be checked. Does the truck engine have the setup for emissions or has it been re routed or eliminated at sometime (someone did away with the emmissions on vacuum)?