86 F-150 Help

[Jmac1773]

Hey, folks.  I just made my introduction post so I thought I'd jump right in and ask some questions if you don't mind. I've had old cars before ('67 Mustang, '67 Firebird, '61 Studebaker 2-door wagon) but I need to learn about my old Bullnose.  Most of my questions center around the carb and engine bay so far. So here we go...

First, I'm guessing this isn't the stock carb, right?



Second, what's missing here?


And here?


Aaaand here?


Bonus question:  What is this wire loop?  It attaches to nothing under the air cleaner cover...


Also, I learned on another forum that the green wire coming out of the DSII box is for my tach - which doesn't work.  What components might I need to get it working again?


Oh... and more importantly, the fuel gauge doesn't work either.  But I'll do some more research on that and post only if my ignorance overtakes my knowledge.  


Lastly, sorry for the neck-bending.  Not sure why some of the pics turned CCW on me.

[Machspeed]

That's a 6 cyl and I can't speak to much of it. I'm pretty sure that your "second" is missing a tube that takes hot exhaust to the choke for choke function.

Others will be on this quickly. Glad to have you.    

[Gary Lewis]

I can answer the picture orientation question.  It is because this forum's software, like most, was written before cameras embedded its orientation info in the metadata within the picture's file.  And smart devices, like your phone, re-orient it before they display it to you.  But this forum doesn't.

The solution is to open the picture in an editing package, some of which are free, and save it.  That usually fixes the problem.  But, be aware that the largest file you can post on here w/o ticking the Big box is 999 KB, meaning 1 Mb won't load.  So when you edit your pics you might want to downsize them to about 500 Kb.

As for the carb, in the first pic the carb's vent to the charcoal cannister below the battery has been plugged.

Also, in the second and third pics the exhaust heat system has been removed from the choke.  Originally the line in #2 ran down to the exhaust and pulled in hot air for the choke.  There was also a clean air feed to the exhaust from the carb, which is probably the line in #3.

The line in #5 is probably the vacuum line to the vacuum advance.

#6 is a vacuum hose on the temp sensor.  Read about that here: http://www.garysgaragemahal.com/air-cleaners.html

On the tach, read about the wring here: http://www.garysgaragemahal.com/tachometers.html.  But that wire probably goes to the coil.

[ArdWrknTrk]

Looks like a stock Carter YF to me. (Even has the bowl vent -plugged with a bolt-)

Gary is hitting on all cylinders, but the loose wire is for the tach.
You can see the other leg of the green wire going off to the coil.

The green wire must be complete from coil to module because it cannot be grounded without it.
The module's transistor opens and closes the ground, which is the black wire to the distributor.

All these trucks (tach or not) have that clipped off wire going to the instrument cluster plug.
You might try to find it and splice it back together.

[1986F150Six]

Hmmm?

Please take a photo of the carburetor on the driver's side. From what I can see, the carburetor currently on your truck does not have the feedback solenoid with two electrical wires. Your truck is a 1986, so should have one.

Take a look at the distributor. Does it have a rubber vacuum hose connected to a cannister? Or, is there a grey plug with multiple wires?

Photos #2 & 3 reflect someone disconnecting parts used for the choke, as has been mentioned by John, Gary and Jim.

Here is a link to how the choke for a 1986 4.9L operates: https://www.ford-trucks.com/forums/1110073-choke-adjustment-101-a.html

Photo #2 is what remains of the insulated metal tube which is connected to the exhaust manifold and brings heated air to the choke housing.

Photo #3 is originally connected to a red silicone vacuum hose which connects on the other end to the exhaust manifold. There is a tube which passes through the exhaust manifold to gain heat for the choke. The fitting on the carburetor supplies filtered make-up air to supply the hot air to the choke housing. Inside of the choke housing is a very small port which has small vacuum leak to draw in the heated air. The original carburetor is calibrated for this leak.

I cannot remember what the vacuum hose is for in photo #4; probably emissions related.

The "loop" in photo #5... there should be a vacuum hose connected to the rear of the sensor which originates at the vacuum tree which is on the intake manifold, close to the carburetor. The front part of the sensor should have a vacuum hose which connects to the servo on the air cleaner snorkle, which controls the incoming cold air. The snorkle has a flexible rectangular hose connecting it to the radiator support opening. On the bottom of the snorkle should be a 2" diameter hose connected to a shroud around the exhaust manifold [front 3 cylinders]. This supplies hot air and allows the sensor to mix hot and cold incoming air to assist in preventing carburetor icing.

[Jmac1773]

Thanks for the replies, guys. Man, I have a lot to learn. This stuff was simpler in the late 60's cars I've owned.  I'm not sure what most of the stuff is that you guys are talking about.

My next obvious question is:  Do I need any of this stuff reconnected?  It just passed a safety inspection as I was buying it so I'm pretty sure it's not needed for emissions since its exempt.  It runs well as far as I can tell but some of that stuff sounds like it might relate to cold weather operation.  Right?  As it's not my daily, and I'm in Texas, I probably shouldn't have to worry about it, right?

Again - forgive all my newbie questions.  I have others (like the popping sound I sometimes hear when I'm shifting from 2nd to 3rd) but I'll wait to REALLY annoy y'all with questions at a later date...

[1986F150Six]

I like your Bible verse reference under the description of your truck!

[Gary Lewis]

I do too, David.  I'd missed that.  

[Jmac1773]

1986F150Six wrote

Hmmm?

Please take a photo of the carburetor on the driver's side. From what I can see, the carburetor currently on your truck does not have the feedback solenoid with two electrical wires. Your truck is a 1986, so should have one.

Take a look at the distributor. Does it have a rubber vacuum hose connected to a cannister? Or, is there a grey plug with multiple wires

Here's a pic of the overall driver's side and a close-up of the carb.  Hope it helps.  



Here's a pic of the distributor.  I believe it's the plug variety you mentioned but want to make sure...


Again, sorry to make you crane your necks.  I'll try to take Gary's advice and edit the pics before uploading them. If I have time....

[Jmac1773]

Thanks re: the Bible verse, guys. Seems even more appropriate these days...

[ArdWrknTrk]

So, your truck has DSII and it looks like EGR delete (from my phone.... sideways)

That would make it more like a mid '70's heavy duty (over 8,500# gvw) setup.

Simplicity is a good thing as long as you don't have to smog test your truck.

[Jmac1773]

Thanks... hopefully that simplicity will keep some money in my pocket.  LOL!

[86 1/2 Brutus]

Welcome to the neighborhood.  Your carb is a Carter YFA non feedback.     Everything that has been said above is absolutely correct and we will be glad to help you with anything that may come up.   First and foremost.  These carburetors are notorious for coming loose .  Make sure it is tight to the manifold, once you ensure it is tight, wiggle the carburetor, if you feel any play at all, you will have to remove it, flip it upside down and there are 4 screws that will need to be tighten'd and use thread locker.   I did an entire emissions and egr delete on mine and is running well now for quite some time.

Welcome to the neighborhood

[ArdWrknTrk]

Frank Wyatt ran into this just yesterday (post in the WHYDTYTT) so, spot on with that advice, Geroge!

[Jmac1773]

86 1/2 Brutus wrote

Welcome to the neighborhood.  Your carb is a Carter YFA non feedback.     Everything that has been said above is absolutely correct and we will be glad to help you with anything that may come up.   First and foremost.  These carburetors are notorious for coming loose .  Make sure it is tight to the manifold, once you ensure it is tight, wiggle the carburetor, if you feel any play at all, you will have to remove it, flip it upside down and there are 4 screws that will need to be tighten'd and use thread locker.   I did an entire emissions and egr delete on mine and is running well now for quite some time.

Welcome to the neighborhood

Thanks for the advise, guys!  I knew I had found a good place when I ran across this community.  Y'all rock!

And I'll check the carb tightness today.  I think its fine as I had my air cleaner off yesterday and didn't notice a wiggly carb when I placed the air cleaner bottom back on... but I'll double check!

[Frank Wyatt]

Yeah, for the life of me I don't know why those screws don't have lock washers under their heads. The next time I have the carb off, I'll be adding lock washers as well as the lock tite.

[86 1/2 Brutus]

I check mine about once per month.  I have to keep a closer eye on it right now as i have changed so many things around, mainly the carb spacer.  Since i rebuilt it, i went with screws that were slightly longer and used loctite to put the 2 pieces back together.    The bolts that go from my carb to the manifold, had to be changed as well because the spacer is shorter then the factory spacer, so the factory studs would no longer work.  i used lock washers and bolts with some loctite.

It is a very good idea to check the carb bolts very often.  I've had Brutus leave me on the road because of this issue with no wrench in site

I do love the 300 Six, but when cranking and shutting down, it shakes violently and things work there way loose under there.  I have issues with my alternator and ac belts as well which to this day can't figure out.

[ArdWrknTrk]

George, Matthew or Dave had problems with those belts that was traced down to a loose bracket on the back side.
I forget which of them I offered this advice to, but it's here on the forum.

[86 1/2 Brutus]

Thanks Jim, i'll try to track it down.  those belts have been giving me the blues for years