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 retarded 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 retarded 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 jerk 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 created a file of pictures in the gallery: 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 tit 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

Might have a High gear ratio, which would make the transmission shift like that, and make the mileage bad, and the engine is running at it's limit all the time.

If the idle is too high, it will make the drivetrain clunk when it goes into gear

Vacuum leaks will make an engine idle high, and smell like a gas leak, find the vacuum leaks.



It would be easier to help you if you broke up your posts into sentences and paragraphs

A lot of people won't read a big mass of print, too hard to decipher what you are trying to ask

Charlie,
I apologize for the thread post not being broken into paragraphs. I had them indented but when I submitted it put it all together. I am going to add again by adding lines of dead space between paragraphs. Hopefully, that'll work.

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 entire 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, & adjusted the idle & thought we had the timing set to 6 degrees BTDC.

We thought we had the timing set to 6 degrees BTDC 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 moveded the dizzy about a 1/4" to adjust the timing 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).

I don't know if us adjusting the timing 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 clip into the hole and also hold the passing gear bar 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 created an album of the pictures in my garage: 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 tit 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 Her's a link to better photo's: http://www.supermotors.net/registry/27354[/URL]

If you have a port sucking air, there is a vacuum leak that needs at minimum capped. From what I can tell, the EGR is not hooked up at all. The open port will cause a massive fuel mileage issue to start with.

Charlie & Fellro,
I just went out to inspect the lines to the tranny & added a few more pics to the link added to last post 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 screw. The inner/lower line connects to the box on the top & connects to the rear of the two tits located on the passenger side of the tranny (it was barely connected from the rubber rotting off around the tit 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 tits on the tranny just be open as it is?

Fellro said:

If you have a port sucking air, there is a vacuum leak that needs at minimum capped. From what I can tell, the EGR is not hooked up at all. The open port will cause a massive fuel mileage issue to start with.

Click to expand...

Fellro,
I capped off the other lines on the EGR too.

Like I said in my earlier post, you may well have a low gear ratio, which would make the truck shift quick like that.

I have 4.88 gearing in my one truck, it is in 5th gear by the time it hits 35 mph

I am posting from my tablet at the moment, when I get to my laptop, I will look at your pictures, and see what you have going on

Thanks for spacing out the thread question, it makes it a whole bunch easier to maneuver

Charlie,
Thanks. However, in your initial thread you stated mine might be geared high but in your 2nd post you stated that you originally stated that mine might be geared low. All I know is that it is all factory as the only thing that's been altered is a 2-1/2" lift in the rear. Is there somewhere I can locate the gear ratio? Thanks again & I hope you get a chance to review the pics soon as we are planning to get together to do whatever we can to fix the problems at 2:00 p.m. (CST) today.

i responded to your other post about the transmission shifting issues. i say vac leak

Bigbeardbiii said:

Charlie,
Thanks. However, in your initial thread you stated mine might be geared high but in your 2nd post you stated that you originally stated that mine might be geared low. All I know is that it is all factory as the only thing that's been altered is a 2-1/2" lift in the rear. Is there somewhere I can locate the gear ratio? Thanks again & I hope you get a chance to review the pics soon as we are planning to get together to do whatever we can to fix the problems at 2:00 p.m. (CST) today.

Click to expand...

High was meant to be low, as a high number ratio.

You have an awful lot of open vacuum lines in those pictures. each line has a purpose. You will need to either block them off, or hook them to where they belong. Take the air cleaner off, and shoot a picture straight down of the motor


I also see the PVS hose and valve look old and needing replaced. that is a good start ( passenger valve cover in the back)

Do you have a power brake booster on this truck?

Charlie,



I have created a new photo folder http://www.supermotors.net/registry/27354/84927 As you can see in the pics I sent a link to, I have one hose going to the tranny from the metal rectangular vacuum manifold bolted to the engine but the other hose is capped off with a screw in it and the 2nd tit on the tranny is just there (naked) with no hose connected & no cap.

Also, the other pics in that same folder I recently uploaded show the other lines that are suppose to go to the gas tank but are cut off just past the bracket that holds them several inches from the gas tank. The gas tank also has two tits with nothing connected to them (a piece of duct tape is covering them).

So, my questions are since I obviously have an electric choke but have hoses that aren't hooked up (1 on tranny, two on gas tank, and one cut that goes into the driver's side rear inner fender well) which of these do I need to reconnect and which one's don't serve any purpose anymore (& why do they not serve a purpose anymore)?

After reading your last post, I went out, removed the breather, & took pictures you requested. They are in a sub folder in the same link. In doing so, I noticed another valve that has a hose going to the firewall (I suspect it goes into the heater) but then has two smaller hoses that connect to two tits on the valve. One is capped off with a screw (runs along passenger side and laying between the valve cover & the carb), the other one runs along the driver's side valve cover and carb and is NOT capped.

I don't understand which of these vacuum hoses should be connected, which should be capped because they don't serve a purpose & if they don't serve a purpose, why? Any assistance on this would be greatly appreciated as I'm ready to hook-up what needs to be and get my mpg & tranny working properly. This is my first experience with an engine or vehicle that's pre-1986. I do NOT have a power brake booster, I have drum brakes with new master & wheel cylinders & lines. Thanks, Dean

Vacuum is key to performance, in this vintage of truck. Get a hold of a vacuum gauge and see what your system is pulling. It should pull 20 lbs at idle. Less means a poor mix, a leak, or bad valves.
All vacuum lines should be capped or connected somewhere, as Charlie stated so well. If they aren't, it only leads to either vacuum leaks or rotting of the lines and internal decay of where they connect to. Every line has a home. Someone apparently tried to pull lines to diagnose a problem or make a temporary workaround to bypass replacing components.
The "clunk" may be sloppy u-joints or pinion bearing, or as mentioned, too high an idle.
Lastly, your thermal heat riser hose from the manifold to the air horn on your breather needs to be there.

Here is one diagram that may help

Here is another

mrfixit said:

Here is another

Click to expand...

The last two posts that were suppose to include the diagrams did not show up. Can you try to re-send them? Thanks, Dean

mrfixit said:

Vacuum is key to performance, in this vintage of truck. Get a hold of a vacuum gauge and see what your system is pulling. It should pull 20 lbs at idle. Less means a poor mix, a leak, or bad valves.

I'll try to get a vacuum gauge tomorrow but don't know where to connect it to check what it's pulling

All vacuum lines should be capped or connected somewhere, as Charlie stated so well. If they aren't, it only leads to either vacuum leaks or rotting of the lines and internal decay of where they connect to. Every line has a home.

I understand that they should either go somewhere or be plugged. However, what I don't know is which should be connected & which don't need to be & therefore, need to be plugged. In other words, in order to get to the best I can, I need to make sure I have ALL lines are connected that NEED to be?

The "clunk" may be sloppy u-joints or pinion bearing, or as mentioned, too high an idle.

I will check the drive shaft tomorrow for slop in the u-joints.

Lastly, your thermal heat riser hose from the manifold to the air horn on your breather needs to be there.

Click to expand...

Can you be a little more specific (ex., air horn on your breather (?)
Tom,
Thanks for your assistance.
Dean

Bigbeardbiii said:

Can you be a little more specific (ex., air horn on your breather (?)
Tom,
Thanks for your assistance.
Dean

Click to expand...

Im pretty sure hes talkin about the tube that comes off the breather,if
you still have the old style breather that is.

There should be a tube that comes off the exaust to it...

I myself am learning on these vaccum diaphrams as Im fixing
to replace my vally pan gaskets,Im getting alot of oil seepage,an
maybe losing vaccum as well...

I see the diagrams just fine... they're in my gallery... maybe I need to go check my privacy settings. Hold on, guys!

Lets try the other way of posting.

As for "capped off", I mean that "even the lines and nipples that you do not yet know the purpose of" should be closed in some way, until you're able to figure them out ( hopefully by the diagrams ). I think I can help better once I can sit down to my computer, instead of trying to do this on my tablet.