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  1. #1

    Default 3.3 Fuel Economy Woes

    I recently reacquired an '80 hatchback I owned two years ago and have made it my daily drive for a while. I know at one point when I had it the first time, I got as much as 25 mpg on one tank which I think is very respectable. Not sure what has happened to it since I had it last, but I filled it up tonight and I was very disappointed. Only got about 12 mpg. Granted, the weather is a little colder right now, but I would hope it would get mid to upper teens anyway. It has a new timing chain and gears and I think it's possible that the distributor isn't adjusted correctly or could possibly be off a tooth or two. I need to check that and also make sure the vacuum advance is working properly. The carburetor will need attention as well. I know it has been replaced although I'm not sure when. May need cleaning, adjustment and a new fuel filter probably wouldn't be a bad idea either. It's not idling right. At a stop, it's hovering around 500 RPM and is a little lumpy. Also noticed a little pulsing or surging around 50-55 MPH. The wires are in good shape, plugs were just replaced, cap, rotor and PCV valve are okay, air filter and breather filter are new, has fresh oil and fresh coolant.

    I'm trying to think of other things I can check that could be causing this problem. Not sure if there's any vacuum leaks, but it looks like most, if not all, of the vacuum hoses are original, so they may be on their way out. Then there's all those little check valves. Could they be an issue? Need to check the tire pressure as well. That could even make a difference. If anyone can think of anything else I should look into that could be causing the poor gas mileage, I'd appreciate your suggestions. Thanks.

    Scott

  2. #2
    FEP Super Member erratic50's Avatar
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    It your timing is out of whack there is nothing much else to discuss until it is in check.

    Timing chains are usually about right out of box. Yes you can degree the cam in, but most people don’t bother as long as it’s close.

    Timing marks for the ignition timing on old motors are not to be trusted. You have options....

    you can remove the #1 plug and put a solid object like a bolt in the spark plug hole that is threaded in far enough to prevent a rotation. Bar the motor over by hand one way until you find the limit and mark it. Go the other way until you find that limit. Mark it. Split the difference between the two marks and mark it. That’s a really good guess at what is really TDC.

    Set your timing with a light off the “good guess” mark while the advance is disconnected and the hose is plugged temporarily.

    Or...... disconnect and plug advance. Loosen the dizzy hold down. Turn the timing to advance until the motor speeds up. Now turn it til it slightly until it slows back down. Play with it until you get to where it is just about to speed up but hasn’t yet. Lock it down and connect the advance.

    With the car warm shut it off and check for dieseling. Restart the car - if it kicks back against the starter and starts hard remove some advance.

    See how it is.

    if you didn’t set the gap on the plugs, go through it, and do.

  3. #3

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    Could it be you remember things better than they were? Ever since I had my first car, a 3.3 '79 Mustang, I've said the 3.3 is the worst of both worlds. Crap fuel economy, crap performance. Zero advantage.
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI, T-5
    '17 Ford Focus ST
    '14 Ford Fusion SE Manual

  4. #4

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    Funny (no, not your situation. You've got all the right suspicions, follow thru with them), the 200 cubic inch (3.3L) straight six in my '66 Fairlane sedan was one of the best on fuel, especially around town, vehicles I have ever owned. I'd put 10 bucks in the gas tank, drive all around and back and forth to work, and would marvel at the fact that when it was time to put another 10 bucks in the tank, I couldn't recall how long prior it was that I'd put the last 10 bucks in the tank... of course, it wasn't saddled with ANY of the "emissions" garbage that newer ones are. The only thing I didn't like, and never got around to changing before having to sell the car, was the vacuum-only ignition advance "Load-O-Matic" distributor, coupled with the "spark valve" on the carburetor. Adding and dialing in a Duraspark distributor would have made it excellent on gas out on the highway too... not that it was bad on the highway, but it was phenomenally fuel efficient with what's usually the worst case... stop and go, around town...
    Good luck with it.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  5. #5

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    As for the carburetor and ignition... a hovering/wavering and lumpy idle is a sign of the idle mixture being too rich, and/or the initial timing could use being increased, and therefore also with an increased initial timing setting, allowing an even leaner smooth slow idle mixture. Surging at highway speeds is a sign that the carburetor's transition or main circuit is a bit lean, and/or there's too much vacuum advance being brought in. Usually most all normal driving up to regular highway speeds is handled solely by the carburetor's idle transition/transfer circuit, but I mention the main circuit in this case due to the meager power that the 200's/3.3L's have, and so it could be running on the main circuit more so than the transition at highway speeds. Regardless, the ignition's settings and function should be examined, and the carburetor should at least be opened up to see if there are any blockages within idle circuit fuel feeds and all air bleeds, and then put back together, verifying correct float level and all other adjustments... particularly too in a case of poor fuel mileage, that all of the choke settings are correct to spec.
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  6. #6
    FEP Super Member gr79's Avatar
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    Parts replaced- carb and timing gear. Unknown circumstances for repair work. Why them?
    Are usual suspects to correct a problem, which they may not have.
    Not something done if car is running good.
    May simply need finer adjustments, or the problem lies hidden elsewhere.

    Found a cracked rubber vac elbow the other day, at the char canist, that was not obvious by any means.
    Old vac lines get hard and brittle. Plastic and connectors can crack, look good, hardened hose keeping them in place.

    Recheck carb, vac lines, timing, anything related to recent repairs.
    Vac gauge is handy for diagnosis.
    Carb adj, loose mounting, incorrect carb. That can happen.
    Debris in carb passages. incorrect connections to carb.
    Stuck choke, closed manifold heat air riser door after warm up.
    Cracked, split, loose, miss-routed vac hose(s).
    Check ignition timing and give engine what it wants. Factory spec can usually be improved on.
    Check all fuel lines rear to front for leaks. Fuel cap too.

  7. #7
    FEP Super Member xctasy's Avatar
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    We drive these cars a lot harder in modern traffic to keep up with Honda Oddyseys and Hyundais that do 16.5 second quarter miles and 40 to the gallon five up.

    ZephyrEFI is right...this 3.3/ C4 engine combo had none of the performance/economy balance the 5.0 of any year did.

    Nine times out of ten, its the leaking four bolt diametrically switch bolts that hold the 1946C Holley on the log intake.

    You have to check it with butane or propane from an unlit source. If idle increases, its a leak when squirted at the carb to log head mating faces.


    You adjust it back with very carefull hand tools and no excessive lubrication to the bolts.



    Curb idle is noramlly never right if someone has adjusted the rod operated kickdown. That must be done right, as per the workshop manual.

    Choke pull off is energized at about 20 " vacuum. It is described on the VECI label as being tested by vac application at points A.

    The 1980 A/C kicker might be in place, (not sure for 1980 B code 3.3's, the 1981's sure had it) and might not be adjusted down when the A/C is not on. Orange knob on the rocker.

    The Hot Idle Control valve is very easy to adjust, but might not be adjusted right.

    The engine has 9 degrees of timing measured as per FoMoCos test procedure.

    If its cold, and you are using a diet of oxygenated gas which is old, it won't give good gas figures.

    The valves that operate the hot air stove need to be working properly, the EGR valve needs to be clean, the 1980 didn't get two path AIR, but air pump on the 1980 was a little more basic to the 1981-1983 B and X code 3.3's. Check the anti backfire valve and the priortiy AIR valve if it has one.

    The primary light off catayst must not be impregnated with gum from leaded gas, or from the normal buld up that happens over the years.

    Its hard to check...you drop the down pipe which requires removing the EGR heating line, a very hard job without the right service tool, as the C3 or C4 trans has a starter motor heat shield and the catalyst a heat sheild as well. It should be checked.

  8. #8

  9. #9

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    I'm not talking about ancient history. I was driving a 1966 Fairlane in the late '90's, and sold the car in 2001. Traffic I drove 'er in at the time, in Windsor Ontario Canada, minutes away from Detroit, was as stupid and abundant as it is anywhere today. Yes, she was no powerhouse, but with about a 9.5:1 compression ratio and every of it's simple engine components in plain sight and no "black box" or controlling "sensor" restraints to mess up good function, she was peppy for 200 cubic inches in a decent sized car, and seriously only sipped it's small ration of fuel to operate among the masses. Another improvement I would have made if I could have kept it, would be to upgrade the manual four wheel drum brakes. Speaking of traffic, I had a pretty unnerving experience out on the freeway with it, where changing lanes became immediately necessary, because it didn't matter how hard you jumped onto the brake pedal with both feet, she wasn't going to slow down or stop fast enough to avoid colliding into the panic braking Toyota in front of me... lol
    Mike
    1986 Mustang convertible ---> BUILD THREAD
    Past Fox-chassis "four eyes":
    1983 Mercury Cougar LS
    1986 Ford Thunderbird ELAN
    1980 Capri RS Turbo

    Work in progress website ---> http://carb-rebuilds-plus.boards.net/

  10. #10

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    Thanks, guys. I appreciate the information. I have a feeling the bulk of tomorrow will be spent checking out as much of this as I can. Taking it to a friend's house for help. He's good with cars and had an '82 Capri RS back in the day. Regarding gr79's comments, the carb had been replaced before I ever got the car. I hope it's still in good condition and just needs cleaning and adjustment. The crank seal was shot and oil had been going all over the place, so I had to fix that. When the timing cover was off, we discovered that the timing chain had slack in it, so we figured we might as well replace it while it was apart.

  11. #11
    FEP Super Member xctasy's Avatar
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    See below

  12. #12
    FEP Super Member xctasy's Avatar
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    The single chain will have slack in it after 1000 miles. Its a 200, Ford econo engine for almost 20 years unchanged. Its supposed to be retarded. The chain is better than the nylon gear to chain drive on the SBF and BBF V8's.

    The A series Mini 970/998/1098/1275 Cooper S derived duplex chain was converted to fit the 200 back in 1965 by the Australians. You can buy a chain like it from Vintage inlines. It won't stretch much like the stock Ford single row one does. All the later Aussie Fords used it from about 1970 onwards. Good upgrade for sometime in the future maybee.

    My 1981 Stang was fine as a crusier and on the highway. It only ever suffered on long 8% or greater up ward grades where all the cars that didn't do 20 second 1/4 miles overtook it. Loaoded, with kids etin' cotin candy in the back laughing at the funny Toyota Supra looking car with Ford badges doing 55 mph max as they sped away doing 65 in there mommas 2.2 liter Camry Station Wagon.....

  13. #13
    FEP Super Member gr79's Avatar
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    Sounds like a good plan. Four eyes on a four eye.
    Check carb is tightly fastened to manifold. They can shake loose a bit over time.
    Check vac hoses where they bend, end, and touch/rub, looseness at connections.
    Need good lighting and close inspection to spot cracks, splits.

  14. #14

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    Here's an update on the car. Timing was set to factory spec, carburetor was adjusted (fast idle and fuel mixture), carburetor was sprayed with cleaner, fuel filter was replaced, a couple questionable vacuum hoses were replaced, PCV valve was replaced (found to be cracked) and EGR valve was replaced (port that it attaches to was cleaned as well). I'm going to try to clean the carbon buildup from the original EGR valve and keep it as a spare. The biggest thing though is that I found that the hoses that go to the ported vacuum switch on the front of the engine by the thermostat housing were disconnected. Were apparently left off by a shop that recently worked on it. I've also found that it's very important to make sure the car is up to operating temperature before trying to take off. It's very cold-natured and has the tendency to stall if not warmed up enough. At the moment, the car runs great and idles beautifully. Got to work with no issues this morning. It may be necessary to rebuild the carburetor at some point and ultimately, I should probably replace all of the vacuum hoses. Since it's running well now, I'm not going to touch anything. I'm now debating about buying some kind of small car to drive to work instead of relying on the '80 as my daily. I know there's other work that the car will need (exhaust, suspension, A/C) and I'll just be able to put it aside and work on it when time and funds permit. Will still drive it some to keep everything in working order.

  15. #15

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    Another possibility to check on is to see if the cat is plugged. I had an '81 zephyr with the 3.3 that always did alright(not great) on gas, motoring around with its typical drone. One night it went quiet, lost power, and fuel economy took a dump. Checked the exhaust and it was barely a breath coming from the tailpipe. Had a high-flow cat and flowmaster put on it and voila! Mind you this was many years ago but i still miss that car. Fell asleep at the wheel and drove it off the freeway.

  16. #16
    FEP Super Member xctasy's Avatar
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  17. #17
    FEP Super Member xctasy's Avatar
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    CATCO catalogue selections for 3.3's for Foxes from 1980-1983 that aren't 3.8 V6's and 1979-1980 Granadas with the 250 has this reference:-

    Fox body primary light off catalyst E1 BE 211 replacement is Catco #66991




    Yep, not well understood cars, very easy to find, fix and refurnish, but they were light for sure, and the Big R can get 'em.

    X cars were simple up to about 1978, then the Foxes were another step into the unknown. There is a lot of Chrysler and AMC parts similarities, with extra electronics and straight out weirdness.

    Despite all this stuff.....,


    they aren't feedback carbed engines, so they are really easy to fiddle with.


    The vast majority of later B and X codes were blue high mount engines with E1 blocks. Ford decided that they would still use high mount blocks, and cast E1 blocks with high mount recesses in the flange accordingly. So its not true to say everything 1981 onwards is generally low mount Big Bell. As the Falcon Six Hnadbook guys say, its hard to be general with Ford. Sadly, people continue to expect low mount sixes with any 1981 to 1983 Fox body, but thats wrong.

    The miss information started here.



    The low mount was quite rare in the grand scheme of things. If its powder grey like this, it'll be a Bee Bee.




    My 1981 was a D8 BE 6015 GE block, while the later highmounts were C4, manual tranasmission, and E1 BE 6015 GE

    On the cat thingy, lots of 1980 to 1982 3.3 sixes, if they've been varnished up without the occassional blow out, they can look like this inside the cat.




    Do as I say, not as I do...You need the right kind of cranked spanner to take the exhaust appart. I had to use an axe...





    Any time you take stuff appart, get some kind of workspace planned, some plastic or metal surface to place the carb and engine parts down on, and take photos, video, and/or label the stuff.





    Its all color coded, but the color coding varies, and 1983 X codes are similar, but not the same as 1980, 81 or 82 B codes. The 1978 to 1979 T codes are different in nearly all respects. Names vary too, so parts decription becomes important.

    X shell Granadas and Monarchs are generally 250 L or C codes, they are a labyrinth of emissions lines, but as long as its not been messed with, it works great.



    There is no negatives with the later stuff, it just looks strange and its a specfic package, which may cause compatability problems if you swap between the different years or engine Vin Codes

  18. #18
    FEP Super Member xctasy's Avatar
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    A quick note.

    The 4-1-4" out let exhaust is found on three engines from 1980 to 1983.

    200/3.3 B code 1980 to 1982 Fox platform

    (care of powerband on Fordsix.com)




    200/3.3 X code 1983 Fox platfrom


    and the one year only 250/4.1 C code 1980 Monarch/Granada

    Without the cat attached, it will fit any engine bay.

    You find the exhast on ebay all the time

    Casting no EOBE 9430 KE


    Replacement cat is around.

    Fox body primary light off catalyst E1 BE 211 replacement is Catco #66991

    Part numbers are under the American Granada, Monarch and Versailles
    Parts Interchange (1975 – 1980)

    See http://jhkaster.bizland.com/Granada/...ange_Final.pdf

    Page 57 on,

    5212 Catalytic Converter, front, Item 125 stamped E0 DZ 5E212 A or Item 125 stamped E0 DZ 5E212 E

    5250 Catalytic Converter back Iyem 129 and 132.

    Page 178 on, 9430 Exhaust Manifold–Right or In line

    Item 337 is E0 BZ 9430 F
    or 339 is E0 BZ 9430 G





    See http://vb.foureyedpride.com/showthre...ont-I6-project



    The big foot ball converter B and X code exhaust found on the 3.3 Foxes from the 1981 model year had a large single outlet






    The stock 4.25 " exhaust football converter B and X code 3.3


  19. #19

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    Hey Scott, for what it's worth my 79 zephyr 3.3L has recently been getting 16mpg city, 27mpg hwy on 97 premium gas in warm weather. I just plugged a vacuum leak so I'm hoping the city number goes up a bit next tank. Did you get new numbers since you did the work?

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