Fuel Economy Issues? Currently 6 mpg! Running WAY to Rich & no

My '73 Bronco is currently getting 6 mpg & the auto. tranny is not shifting correctly. It seems to be running way too rich. This morning I could smell pure gas when standing beside it running as well as when raising the hood but no leaks! This weekend we just replaced the dizzy, points (After replacing the points in the dizzy over the weekend, it would finally run), plugs & wires, carb (rebuilt original Motorcraft from Guaranteed Carburetors), coil, timing chain & gears, water pump, radiator & hoses, thermostat, 13 gallon gas tank & line (Only 1 tank (rear)). I have no idea what mpg it had previously as I recently purchased it, & new tranny fluid & gasket.  We thought we had it ******** 6 degrees from TDC but this morning after cranking it up it sputtered in idle and went dead when putting in reverse but would crank back up and run but had a loping sound to it. So, this afternoon we ******** the time a little more and adjusted the idle and now it goes into reverse without sputtering or stalling but still makes the "clunk" noise when initially putting into reverse, & runs as smooth as a sewing machine except for the auto tranny shifts from 1st to 2nd within 3 seconds (around 5 mph) of putting in drive and shifts to 3rd withing 3-5 seconds thereafter (around 10 mph). However, has plenty of power  and when punching it on the open road it has a lot of power (like a passing gear but you can't hear or feel it shift it just speeds up ( got up to 90 mph today).and runs as smooth as a sewing machine except when backing out of garage (when initially putting into reverse it makes a "clunk" and slight quick **** as going into reverse. I don't know if retarding it to be more precise will fix the mpg issue or not (again, it was late in the eve before we adjusted it)? Also, I don't understand why it shifts from 1st to 2nd and then to 3rd all within 10 seconds or so without punching the gas. The passing gear bar going from the tranny to the throttle linkage was not connected when I purchased it. It has slight scrape marks that would perfectly match-up to it being connected on the lowest part of the throttle linkage but the end of the spring that goes in that hole is not long enough to also hold it in place.So, what I did was place it on the pin coming out the top left side of the throttle before placing the arm there that has the ball on the end that clips it to the end. I don't think that is the correct place for the passing gear bar & therefore, don't know if that is contributing to the shifting issue or not (?). Lastly, again I have installed a reman. Motorcraft carb. I have the two vacuum lines from the dizzy connected to the ports they went to one the previous carb. but there is a threaded port on the  rear passenger side of the carb that sucks air and I don't see what, if any, hose, etc... goes there. I have attached pictures: 1. is of the rear of the carb. (is a circular factory part just behind the carb with two hoses connected to it(1 is cut off about 2" from part & the 2nd one runs about 2' but is plugged on the other end), 2.is of the threaded *** that sucks air constantly while running but do not see what, if anything, should be connected to it, 3. is of the throttle linkage and shows the passing gear bar connected to the top, & three shows the passing gear bar as it rides above the engine to the throttle linkage. Any assistance would be greatly appreciated as I am out of ideas& my element with these things. Thanks, Dean

Sorry.., I don't know where all the EB members/owners are these days...??

The folks who run with automatic trannies, V8's & such. 

Maybe they got their help here & just don't show up to help others..? A true wonderment... :huh:

Anyhooo.., I'll do what I can fr. memory.

That threaded tube sticking out of the choke housing is, I think, what you're talking about.

That is the warm air feed that shuts off the (stock) choke.

You have an electric choke as I see it. You should put a rubber plug over that hole.

If it's "sucking" air.., that would ruin your mixture settings.  (i.e. a vacuum leak)

That brass tube sticking out just above there should have a rubber plug as well.

It's letting dirty air into the carb throat.

That round pod at the rear is a vacuum canister of sorts.  There should be no leaking/cracked

hoses. (those hoses are there acting as plugs) It's fed by a hose coming out the back of the carb.

Point being none of these hoses should leak.

One vacuum line runs to the trannie modulator on the pass. side of trannie.

The modulator (as I mentioned earlier) helps the trannie function. There should be no air leaks

or fluid in the modulator.

The pics are a bit dark & a bit to close-up to get a handle on what's going on there.

Also, they came in sideways...

As I see it..,  that spring is not needed. What's snapped onto the carb throttle linkage

appears to be correct in that it's the adjustable throttle linkage arm...., not the kick-down rod.

Looks like the kick down rods is hooked to the lower firewall throttle linkage.

Maybe that's where it belongs.

(the kick-down rod does just that.., activates passing gear)

As I recall.., the dizzy vacuum line goes to the small tube just below & to the right of the choke.

BullyBob,

    Thanks. I will submit better pics this afternoon. The vacuum line from the front of the dizzy goes onto a *** on the left side of the carb and the hose from the right side of the dizzy goes to a *** on the right side of the carb. The round pod behind the carb. has two vacuum lines coming out of it. The lower one is several feet long but has been plugged at the end and the upper one was cut off & is several inches long but is not plugged. Neither the threaded tube or the brass *** have been plugged. The passing gear bar is connected to the upper *** and is held on by the rod that has the round end connector on it that seats firmly on the ball on the end of the ***. So, let me make sure I got this correct. The two vacuum lines coming off the round pod need to both be plugged (So, since the lower one of mine is plugged I just need to plug the top one). I need to plug both the threaded tube & the brass *** on the rear of the carb. The passing gear bar should be on the *** at the top of the throttle linkage and then the rod connects to the end of the *** which will hold both of them in place (which is the way mine is currently)? If this is correct, should doing these things help it to not shift from 1st to 2nd & then to 3rd all within +/- 10 seconds after putting into drive (which is one of the two issues I'm dealing with) or will this help get better gas mileage (currently at +/- 6 mpg) or both? Thanks again for your assistance, Dean 

I'm doing this fr. memory.., that's why I wish some members with this same eng./carb would jump-in..!!!

Say "passenger" or "driver" side.., not left or right..., saves confusion.

I can't help much more W/O a V/8 rig here with an auto trannie to look at.

There should be a vacuum line runn'n to the trannie modulator.

There should be NO vacuum leaks or else the carb. settings/tune won't be right.

Vacuum leaks cause a "lean" running condition. Not good for the eng.

I have attached better pictures here.

Thanks again, Dean

One more.

Much better pics..!

You see that 'lil cube shaped thingie with a bolt thru it with several vacuum lines plugged into it..?

That's a vacuum manifold to provide vacuum to several items.

The tubes that go up & turn down may be (one) that goes to the trannie. The modulator has to have vacuum.

Now that I see the round one on  lower back of carb., that's likely a vacuum  diaphragm to operate

other items. 

I now see the kick down rod.., attached to the same snap-on ball for the throttle.

I don't think it goes there as it would have the oposite affect.

I think it goes on the small hole the spring is attached to BUT, don't quote me.

Thanks,

I just got in from a meeting & will run out & check the 3 items you mentioned. However, do both of the vacuum lines coming out of the round pod? As I stated (& also can be seen in several of the last pics I uploaded) the lower of the two is capped off with a bolt in the end of it but the top one that's shorter (around 2" long) is not capped off. So, do I need to cap it as well (pictures 5 & 6) without having to purchase a kit? I do not have the diagram on my hood or rad. plate that you sent but I took a picture of yours so, I have it now. Thanks, Dean

OK, in the third picture, the round thing id the vacuum operated EGR valve.  If your air pump and associated equipment is removed it has no effect on your engine.

In picture 5 the silver tube is for a hot air heated choke spring, but since you have an electric choke attached it is redundant and should be capped.

I would cap the tube in picture 6, since it only represents a air/vacuum leak and will effect the carb operation.lve on the

I agree with BB on the coil looking thing, probably goes to the tranny to the shift valve.  You need a vacuum line from the vacuum tree to the valve on the tranny to get it to shift properly.

In picture 1 I see a throttle kicker solenoid that is used to prevent the throttle from slamming shut when you decelerate to prevent a stall.

More to come after I look the pictures over a bit

The mechanical kick down does not hook to the same place as the throttle.  Like Bob said, it wouldn't work if it was hooked there.  On my carb, it required a kit to add the connection for the mechanical kick down.You need to find out where the other end of those curly pipes go. 

Do you have a diagram on the hood or radiator support that looks like the second picture?  There is an idle adjustment procedure in that picture that probably would work on your carb.  The hot idle adjustment ***** on the side where the throttle hooks up should be adjusted after all the other adjustments are made.

Picture 3 is a better view of the kick down attachment, this is on a Holly but the operation is the same.

Seabronc said:

The mechanical kick down does not hook to the same place as the throttle.  Like Bob said, it wouldn't work if it was hooked there.  On my carb, it required a kit to add the connection for the mechanical kick down.You need to find out where the other end of those curly pipes go. 

Do you have a diagram on the hood or radiator support that looks like the second picture?  There is an idle adjustment procedure in that picture that probably would work on your carb.  The hot idle adjustment ***** on the side where the throttle hooks up should be adjusted after all the other adjustments are made.

Picture 3 is a better view of the kick down attachment, this is on a Holly but the operation is the same.

Click to expand...

So, I need to cap both the silver threaded pipe & the brass tube that both come out the back of the carb. correct? Also, the Motorcraft Carb rebuilt from Guaranteed Carburetors was suppose to be identical to the one that was factory on my Bronco (I had to give them the numbers off it & they said this one is the same one) so, since my vehicle had a kickdown arm why is there not a place for it to connect on this carb.? I also added a few more pics to the link http://www.supermotors.net/registry/27354/84923   that contain the two lines from the rectangular metal box that has several lines running from it. The outer/upper line goes from the driver's side of the box down toward the tranny but is capped off on the end by a *****. The inner/lower line connects to the box on the top & connects to the rear of the two **** located on the passenger side of the tranny (it was barely connected from the rubber rotting off around the *** so, I cut the rot off & connected it tightly. Should the outer/upper line be capped off like it is & the front most of the two **** on the tranny just be open as it is? I also capped off the second line from the EGR (the 1st one was already capped off with a ***** in the end) Thanks, Dean

"So, I need to cap both the silver threaded pipe & the brass tube that both come out the back of the carb. correct?"

YES..!  Basically what we're saying is there should be no hoses, tubes, pipes, ******* exposed to atmosphere.

Especially if there's air being sucked into the intake manifold.

"the Motorcraft Carb rebuilt from Guaranteed Carburetors was suppose to be identical to the one that was factory on my Bronco (I had to give them the numbers off it & they said this one is the same one) so, since my vehicle had a kickdown arm why is there not a place for it to connect on this carb.?"

It sounds like you took the carb off...?  If so, did you have any parts left over upon assembly..?

Again, my guess is it goes where that un-needed spring is attached.

"two **** located on the passenger side of the tranny (it was barely connected from the rubber rotting off around the *** so, I cut the rot off & connected it tightly."

I mentioned this several days/posts ago.., there should be no rotted/sloppy/cracked rubber hose connections.

Especially there at the modulator.

I think you need to find an early Ford Mustang, Ford Fairlane, Ford pick-up, etc.

& have a look how the kick down hooks up. (I know it doesn't go where you have it.) (better to just leave it un-hooked)

I may be able to find one around here. (there's car shows here now-n-then)

However, the modulator needs to be functioning correctly.

P.S.  Looking at the Chilton book.., it's possible they gave you a carb. for a 3speed manual trannie.

The pic in the book shows  a kick-down adj. ***** & (looks like) an attach point on the carb linkage

for the kick-down.

(real small pic, not real clear)

The kick down hardware only comes as a kit on the Holly so I assume that is the same for your carb.  Need to see a picture of the trany where the vacuum line is attached. 

That modulator might be bad, did you see any tray fluid in the vacuum line you cut back? 

In your supermotorss link, what is picture 10 of?

What Tranny do you have?

Sb..,

I think #10 is the bottom of trannie showing the modulator in upper right....

That brass pipe appears to be for the evaporative emissions system.  From the look of the engine, I assume that the evaporative emissions system has been removed, so yes, cap it. As far as the EGR valve is concerned, you can remove the hoses and the connections to it don't need to be capped.  What you might want to do is remove the carb and the plate the EGR is attached to and make sure that the valve is seated closed or it will be allowing hot exhaust gasses to be inserted into the engine at the wrong time. 

My suggestion is to get a vacuum diagram for that truck and restore the vacuum system to it's original state. Not everything that has a vacuum hose or electrically operated solenoid can be removed and expect the engine to run properly.  Believe it or not, those engineers knew what they were doing when they designed it. 

Also, you may still have a carbon canister under the hood.  At least make sure it is connected to the fuel tank vent valve.  That will make sure the tank doesn't over pressurize when out in the hot sun and also prevent it from collapsing and causing fuel starvation when the oposite weather conditions occur, OR, as the fuel is sucked out of the tank by the fuel pump. NOTE: DO NOT HOOK THE BRASS PIPE ON THE CARB DIRECTLY TO THE CARBON CANISTER !!!  That connection requires some other valves that control when the vapors are injected into the carb.  If you hook it directly, it will **** gas from the tank through the vent line.

Oh yah, the clunk you get when shifting into reverse may be caused by U-joints, wear in the differential, etc. in the running gear.  Put the rear end up on Jack stands and check for slop in the drive line.

I called Guaranteed Carb & asked them to send me back my kockdown bar connection piece. They said they would OR they'd reman mine & send it back to me. I told them to just send the knockdown connection piece. Do either of you see a reason why I should get my old one remanned & put it back on (other than the knockdown connector)?... I will check the items y'all mentioned this evening. Thanks again for all your help thus far!

You see that 'lil cube shaped thingie with a bolt thru it with several vacuum lines plugged into it..?

That's a vacuum manifold to provide vacuum to several items.

The tubes that go up & turn down may be (one) that goes to the trannie. The modulator has to have vacuum.

BullyBob,

     Upon looking further I was mistaken when I stated that there are 2 lines coming from the EGR & the lower one is capped off with a *****. I just went out & looked again & this is how the EGR & the cube shaped vacuum manifold are: 1. the EGR only has one port/*** & it is the one that has a 2" rubber line that wasn't capped off (after reading what SeaBronc stated, it doesn't matter whether it is capped or not), and 2. the cube shaped vacuum manifold actually has four ports/**** (one on the driver's side, two on the lower top side of it, & one on the right side). The line going from the driver's side of the cube shaped vacuum manifold down toward the tranny is capped off on the end by a *****. The line on the top *** on the top side connects to the rear of the two **** located on the passenger side of the tranny (it was barely connected from the rubber rotting off around the *** so, I cut the rot off & connected it tightly. Should the line from the driver's side of the cube shaped vacuum manifiold be capped off like it is & the front most of the two **** on the tranny just be open as it is or should that line be connected to it), and the lower *** on the top side of the cube shaped vacuum manifold is capped off.

Seabronc said:

That modulator might be bad, did you see any tray fluid in the vacuum line you cut back? 

In your supermotorss link, what is picture 10 of?

What Tranny do you have?

Click to expand...

1. No tranny fluid in the end of the line I cut back about 1" & placed back on the *** on the tranny.

2. Pic #10 is exactly what Bob thought. One of the rubber lines that start as tubing and then curls before turning downward toward the tranny and then becomes rubber from the cube shaped piece screwed to the engine goes to the front of the two **** on the tranny while the other rubber line that started as as tubing has a bolt in it while the *** you can see in the picture has nothing connected to it or capping it off.

3. To my knowledge it is a C4 tranny. It is the one that came on it from the manufacturer in Oct. 1972.