ok i'm back and need some serious guidance with goals

I just cant seem to figure this motor out. I have been doing a lot of lurking with the search button and reading a lot of old info but Im not sure how applicable it is with all the ethanol in the gas pumps now and all the other factors that have popped up I the last 5 years.

I have a 81 Fairmont with the 200inline6 and whatever automatic ford bolted to it. rearend is a 7.5 with 2:73 gears. and im running mustang 15inch "tenhole" rims with fairly tall tires but ive done the math and my speedo is only about 1-2 mph off with the gps on my smart phone.

my main complaint is that the gas milage plain sux. ive been reading how a lot of you are getting close to 20 mpg, and I cant get more than 12mpg.

im starting to wonder if the problem is my carb itself as I cant seem to find ANY info on it whatsoever. my best guess is its a "autoline" brand replacement the former owner bought at autozone and slapped on there but its spits and sputters and just isn't a smooth and im used to brawny 750double pumpers...

the car is stock except for a nice ACCEL ignition coil with matching wires, and I had the cat deleted out of the exhaust pipe and a 2chamber flowmaster added. timing is set at 10*degrees and plugs are autolite 46's gapped at 52

pics of carb and the motor.

FairmontAddict":2slsypt7 said:

I just cant seem to figure this motor out. I have been doing a lot of lurking with the search button and reading a lot of old info but Im not sure how applicable it is with all the ethanol in the gas pumps now and all the other factors that have popped up I the last 5 years.

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it all still applies, ethanol will reduce fuel economy a bit compared to straight gasoline though as it burns colder than straight gasoline does, reducing the thermal load available. with E10 this can be mitigated somewhat through tuning.

I have a 81 Fairmont with the 200inline6 and whatever automatic ford bolted to it. rearend is a 7.5 with 2:73 gears. and im running mustang 15inch "tenhole" rims with fairly tall tires but ive done the math and my speedo is only about 1-2 mph off with the gps on my smart phone.

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you trans is probably either a C3, C4, or possibly a C5. there are ways to tell, the C3 has 13 bolts that hold the pan in place, the C4 has 11 bolts, and the C5 has a deeper bell housing, that though still two piece does not have the step the C4 bell housing has where the bell meets the case. the C5 flows more smoothly and looks like it could be one piece.

my main complaint is that the gas milage plain sux. ive been reading how a lot of you are getting close to 20 mpg, and I cant get more than 12mpg.

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i ma getting 15 with mine right now.

im starting to wonder if the problem is my carb itself as I cant seem to find ANY info on it whatsoever. my best guess is its a "autoline" brand replacement the former owner bought at autozone and slapped on there but its spits and sputters and just isn't a smooth and im used to brawny 750double pumpers...

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start by rebuilding the carb yourself and making sure the float level is set right, often times the float is set too high on rebuilt carbs, mostly because the people doing the rebuilding dont really check the float level, they just put things together and send it down the line.

the next thing you want to do after you rebuild the carb is get the adjustments right on it. including the accelerator pump adjustment.

the car is stock except for a nice ACCEL ignition coil with matching wires, and I had the cat deleted out of the exhaust pipe and a 2chamber flowmaster added. timing is set at 10*degrees and plugs are autolite 46's gapped at 52

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push your initial timing more, advance it until you get pinging under part throttle loads, and then back off until it stops. you might also make sure that your distributor is operating properly as well. for instance pull the cap and twist the rotor in the direction of its rotation, clockwise as i recall, and then release it. you should be able to turn it easily, and it should snap back reasonably quickly and fully. if not then there is an issue with the mechanical advance that needs to be attended to. while the cap is off, check the vacuum advance for proper operation. take the vacuum line to the advance can and suck on it, and watch the advance mechanism. if it moves freely, then put your tongue on the lines opening, and see if the advance arms moves or not. if it moves then it isnt holding vacuum and it also needs attention.

once you get the current fuel and ignition system optimised, then we can dig deeper. the stock compression ratio for the 3.3l for our years(i have an 82) is around 9:1. we need to bump that up about 1/2 point to improve fuel economy and still run 87 octane fuel. taking the head down to your local machine shop and have them mill the head about .015" should do the trick. while the head is off you can clean up the valves as they probably have a lot of junk built up on them that restricts airflow. after that a carb swap is in order. the weber 32/36 progressive carb is a good one to use. if you have the head off for increasing the compression, have them also mill the log to allow a direct mount for best results. you can use the two barrel to one barrel adapter, but remember it raises the carb about an inch or so, so watch the hood clearance.

the carb adapters can be found here;

http://classicinlines.com/proddetail.as ... -DGV-SWP-K

this one is a swap kit, you choose the carb you want, there are two to choose from, and you get the adapter. it bolts on to your log head with no mods. air cleaners sold separately.

http://classicinlines.com/proddetail.as ... -DGV-CON-K

this one requires modding the log head for a direct mount, the adapter is included though, and again you select the carb you want. again air cleaners sold separately.

I will try adding a couple degree's of timing and run 12*degrees.


also someone has deleted the smog pump and was curious what I could do with all the junk under the hood like EGR or anything else I could get rid of to make it run more efficiently.... there is a lot of unneeded looking tubing and lines that are either pinched off or blocked off by the previous owner.

Make sure the choke is opening completely.
Oh and in that first pic, your engine is installed upside down...

FairmontAddict":3iet3qp4 said:

also someone has deleted the smog pump and was curious what I could do with all the junk under the hood like EGR or anything else I could get rid of to make it run more efficiently.... there is a lot of unneeded looking tubing and lines that are either pinched off or blocked off by the previous owner.

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Well that's a lot of your problem with having such poor fuel mileage disabling the emissions gear causes lots of trouble on the later model engines. If you want to use most of the parts you have now, you will need to make the EGR system operational and be sure to clean its passages and install a fresh gasket. An EGR is only operational at higher speed so it wont hurt your performance. Also install a factory air cleaner assembly and hook up its hot air stove pipe and it related vacuum lines. That should net you a good increase with the work you have already done.

Otherwise if you want to strip off all that emission gear you will also need to change out the carb, recurve the distributor, open up the engine to advance the cam, and also would help to add a little more compression. Good luck

Just as an insight, before I swapped to a 2bbl carb, I would also get around 10-12, and that is with rebuilding it properly and adjusting it properly, not sure what the problem ever was, at this point I can't calculate my mileage with 2bbl since my speedometer doesn't work! But honestly, I think my problem was the carb, it looked like someone had messed with it a little too much and could never get it to run reliably. Just my .2 cents

-Nick

Howdy Back Fairmont addict/Middle Schooler;

Some of this will be a repeat from the foureyedpride site, but here goes. The late 70s early 80s 200/3.3 engines suffered from corporate crutching to achieve better EPA and MPG numbers. There are, basically, four main factors that contribute for their lack of performance and economy. They are; 1. the Holley #1946 carb (Which is what your's appears to be, although reconditioned and rebuilt by Autozone). It is not very tunable. It is very complex, linked to many vacuum, thermal and electrical switches all designed to operate cleanly. When new and functioning as designed it ran fairly smoothly. But as systems aged and/or failed it became a nightmare to assess and diagnose. 2. The standard OEM compression rating for a 200 engine in '81 was 8:1. Not good for mpg or performance. 3. Cam timing was advance to favor low speed operation to go along with the high rear gear, the auto trans, and (Supposedly to improve mileage. In reality, the engine spend allot of time lugging. 4. restricted exhaust.

The good news is that these cars have the best in ignition and air cleaner systems available. The Dura spark II ignition is super. Just make sure it is working correctly. rbohm described some old school (But good school) techniques to asses the vacuum advance system. but not that there are several in between switches. between the distributor and the carb. Some of these switches can be eliminated, allowing you to go directly from the carb to the vacuum canister. The Vacuum canister needs to be able to be activated by engine vacuum suction (Suck to advance ignition) and to be able to hold vacuum. As vacuum diaphrams age, they become weak or brittle, or worse, leak. Neither are good. Using rbohm's techniques will allow you to assess the vacuum advance function.

On the air cleaner, it has the ability to draw hot air off the exhaust manifold on cold starts and then cold air once operating temperature is achieved. Both good things. Just make sure the air cleaner filter is clean.

So, first assess the carb. NO leaks, vacuum or gas. ascertain that the float is not too high, that the accelerator pump is as lean as possible, that the automatic choke is opening completely and timely. Any or all of these need to be right. Next assess the distributor advance mechanisms as rbohm described and repair as needed. Once the carb and ignition issues are resolved, that is the time to look farther.

My recollection is that this car sat for a long time. That there was a leak in the gas tank. Are you driving it regular now? Anything else you can tell us about the history of the car? I see the Cat converter still in place. How was it deleted?

Sorry to be so long winded, but knowledge is the beginning of understanding. That's where to start. Given that, did I already mention the value of buying a shop manual for your vehicle? They are pricy, but worth it IMHO.

Keep us posted.

Adios, David

CZLN6":2tf1a2zy said:

Howdy Back Fairmont addict/Middle Schooler;



My recollection is that this car sat for a long time. That there was a leak in the gas tank. Are you driving it regular now? Anything else you can tell us about the history of the car? I see the Cat converter still in place. How was it deleted?

Sorry to be so long winded, but knowledge is the beginning of understanding. That's where to start. Given that, did I already mention the value of buying a shop manual for your vehicle? They are pricy, but worth it IMHO.

Keep us posted.

Adios, David

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the car seems to run fine but has a pretty decent spit/sputter almost always at 35mph. also it had until recently a check ball blocking the EGR to the carb itself which I took out just a few days ago and now it stutters pretty good when I first take off after letting the car sit for a while but goes away after some driving.
the carb itself is brand new.

I replaced the gas tank with a new one from spectre. as far as the cat I had it cut out . are you saying there is an additional cat on the factory header itself? I REALLY want to put one of classic inlines header's on the car but I have Air conditioning and it doesn't look like its going to happen.

FairmontAddict":1736w0bc said:

I replaced the gas tank with a new one from spectre. as far as the cat I had it cut out . are you saying there is an additional cat on the factory header itself? I REALLY want to put one of classic inlines header's on the car but I have Air conditioning and it doesn't look like its going to happen.

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yep, the factory exhaust manifold has a catalytic converter built in, thats the large can you see that bolts to the manifold.

as for classicinlines headers, i dont think mike(azcoupe) has any that fit the fox body anyway, but you might pm him and see what he says. understand that he is a busy man so give him time to get back to you.

FairmontAddict":27og7txl said:

my main complaint is that the gas milage plain sux. ive been reading how a lot of you are getting close to 20 mpg, and I cant get more than 12mpg.

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One important factor in gas milage is how far is your main comute. I get no better than 13 mpg when driving a 3 mile one way comute with my 170 maverick.

FairmontAddict":2llxxjwc said:

pics of carb and the motor.

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JackFish":2llxxjwc said:

Make sure the choke is opening completely.
Oh and in that first pic, your engine is installed upside down...

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I don't know so much. JF.

Using the correct Inverted Image method of view, the top one is okay, the other four are upside down.





As for headers, the one he has will fit a Fox with a little work.

If you're not using the A/C then pitch it. You'd be surprised on how much weight the A/C pump and condenser put on the front end. Lighten up the car as much as possible. A switch to 3:08 gears would help if you plan on leaving the 10 holes on it.

JackFish":mn2qstck said:

Make sure the choke is opening completely.
Oh and in that first pic, your engine is installed upside down...

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actually he did that on purpose so that xctasy could see what was going one. :mrgreen: :mrgreen:

Finally, a joke. We are so damn serious around here...

And on topic, rip all that emission crap out, plug the holes and be done with it.
You'll need to run a line from the carb to the dizzy but that's about it.
Unless you live in California that is.