Not new to the 300 motor as I had a 76 and got rid of it after buying a home but after 12 years the home is done and I bought a 87 econoline that has the dreaded feedback carb. Did not know this untill I happened to stumble onto these forms.

After all ive read still not sorry for what ive done as I surley could not live with this. see photos of motor before and after..

I could not beleave the differance between the 76 and 86 300. So much extra junk in my way it made me sick. And all do to emissions and feedback carb. So I rape the motor of most and find out through these forms its a bad idea..wont run right etc etc.

Well I must have gotten lucky or something as it starts first time every time [ not started for 3 weeks in sub zero temps turn the key and rolls over no problem] and runs strong..just like my 76. So im happy about that. But something I just dont understand..--

Ive read the carb goes into limp mode without computer and will set timing at 10 btdc. And may run a little rich.
Also read that 10 btdc is standard for this motor so im a little confused ?? I keep reading its a problem as it will run a little rich . If this is standard timing setting whats the problem.. better a little rich that lean right ? I mean if these are the manufacturers recomondations I dont see a problem...If it means I cant fine tune it for a couple more poneys or a mile more per gallon well its really not a concern of mine. Its a ******* wagon not a hauler.

Dont know my MPG yet..if its that bad will consider a duraspark II .
Question being is 10btdc really such a bad thing ??
　
Thanks guys

Rearenginebefore_zpsc32cff67.jpg Photo by wannavan | Photobucket

　
　

 

10° is the base timing. While you're driving, the mechanical and computer advance can increase the timing to as much as 40° advance. Then the engine is lean, it takes longer for the spark to burn through the fuel, so the timing advance is more. This leads to better gas mileage at cruise, etc.

If you're in LIMP mode, your computer won't advance the timing, which also leads to loss of power. The mechanical advance still works (since it's based on how fast the distributor spins), so it will still go to around 25 - 30 max, but that's still not at all ideal.

Too much fuel is a safety thing and, while it's not as damaging as lean, it can cause other problems in the long run, such as damaging the cat, fouling spark plugs, etc. It also causes a loss of power. More gas does not mean more power. The perfect amount of gas is what gives the best power.

So no, it's not a good thing to drive the vehicle around in LIMP mode and just leave it there.

 

Thanks for the informative post . Have a better idea on how it works. Am glad to hear the mechanical advance will still work and help matters Ideal or not.
　
The mechanical advance still works (since it's based on how fast the distributor spins), so it will still go to around 25 - 30 max

Is there any way to determine at what RPM the mechanical advance would be ineffective ? So it would not need to advance more than 25 or 30 ?
Assuming RPM would determine how fast the distributor would spin .

Wondering if cruising at 60mph with a 4 speed overdrive and a 3.50 axle would require the timing to advance more than 25 or 30 .
Hope this question makes sence. Thanks.
　
　

 

Computer controlled (and earlier models, vacuum controlled) was to give much needed timing when there wasn't high RPMs.
For example, on my Bronco, I'm at 26 mechanical advance at 2100 RPMs, where I'm cruising at 65mph. But, because my engine's at high vacuum (around 12hg) which means my engine's not working very hard and is at a lean cruise, my vacuum advance pulls another 14 timing. So, instead of 26, I'm at 40. That makes a huge difference in gas mileage. Even more so with overdrive since you won't have a lot of RPMs at all. When I had overdrive, I was at 1700 at 75, which if it was just mechanical advance, I'd be at around 15 - 16 timing. Not much at all.
Your computer does the same thing as the vacuum advance and adjusts it so that the timing increases when the engine isn't working hard. It helps a lot.

Don't forget though that timing is one thing, but running rich all the time is another, which can foul a lot of other things up.

 

AbandonedBronco is right 100%. Vacuum advance allows the timing to change based on the load of the motor. The harder the motor is working, the more the throttle has to be opened up (which causes ported vacuum to the distributor on DSII models to rise). The more the throttle is opened, the more fuel is pulled into the motor. More fuel means that the timing has to be advanced so that all (or nearly all) of the fuel is burned and the motor can produce more power to work easier. When ported vacuum rises, it pulls on the diaphragm in a vacuum advance canister and causes the timing to advance.

On a computer controlled engine, the computer senses the increase in throttle and increases the fuel flow to compensate for the throttle. At the same time, it senses the vacuum drop and then advances the timing using a chart that is stored in its memory to safely advance the timing for best power without damage to the motor. Too much timing can cause detonation (pinging) and modern EFI motors have knock sensors that will allow the computer to detect pinging and retard the timing so the motor isn't damaged.

Your motor really needs either all of the feedback equipment restored like it was from the factory, or a Duraspark II swap has to be done so you can have a properly functioning carburetor, and a fully working distributor. This way, your motor runs and produces the best power, the lowest emissions, the best gas mileage, and runs the best that it can.

No amount of mechanical advance, in my opinion, can make up for the load-based adjustments in timing that vacuum advances or computer controlled timing advances can provide. Remember that mechanical advance increases based on engine RPM and not load, and can only increase up to a certain point.

A simple way to look at it is that mechanical advance is static, but vacuum advance is dynamic.

EDIT: I just had a brain phart, but didn't the OP say his van was an 87? Wouldn't an 87 be EFI and not a feedback YFA? Is it because his is a van or because it's from Canada or something?

 

My mistake guys its a 86 van. 300 I6

OK guys was doing my best to avoid a duraspark 2 conversion.. as I saw it .. plugged cats is not a problem as I dont have any and fouled plugs is just a matter of cleaning or replacing every few years. As far as power goes well I must have lucked out as it runs like a charm and has more power that ill ever need. I cruise at 60mph in all my vehicles to save fuel and am not hauling anything. If I floor it at 60 it accelerates strong and have no pinging or deisiling at shutdown. Not a habit of mine mind you just do this for testing.

As for restoring feedback equipment well thats out of the question [see photos in 1st post] just cannot live with all that junk in my way and trying to trouble shoot if something does go wrong..can you imagine. Trying to find parts would be another horror story. I really envey you guys in the states with your scrapyards . Here in Canada we dont have that option [another reason was trying to avoid a duraspark conversion] our yards are tiny compared to yours ..older vehicles are crushed right away..theres no market for there parts here.

I will finish the interior this summer and run it as is to find out my MPG and consider a duraspark conversion next summer.
Will only put about 5 or 6 hundred miles on it this summer I hope that wont hurt anything. One destination is Vanfest in Aylmer Ontario and will try to pickup the wireing harness I need as I understand this will be the hardest part to find.

Am still confused as to why I have to change the carb as with everything dissconnected does it not just work as a regular carb?
Have read one poster here mention he did the conversion with the feedback carb intact and had no problems? Is this possible? I hope so because finding a carb would be another headache for sure. I will search for that post.

Well in the back of my mind I knew this needed to be done but just didnt want to do it..but after reading these posts I have a better understanding [somewhat] and feel I have no choice. This is a rust free van from Nevada that looks like it came off the assembly line yesterday . Very rare to find in Canada and plan on keeping it well into retirement so I better take car of that motor eh.
　
Once again Thanks for the informative posts guys

Vanleft_zps4526c0e0.jpg Photo by wannavan | Photobucket
　
　

 

That's a good looking van!

If it runs fine and doesn't ping with plenty of power, drive it the way it is for now. You won't hurt anything. But, bear in mind that you'll never get all the power out of your motor nor the best gas mileage. The 300 is an incredibly tolerant motor.

The feedback variant of the YFA allows the computer to control the fuel mixture just like an EFI vehicle. There should be an oxygen sensor in your exhaust. Without the computer controlling the fuel mixture, who knows if it's lean or rich? You'll know if it's lean if you get backfires out of the exhaust, and if it's too rich you'll spew black smoke. If it does neither, assume it's close and don't worry for now.

If you go to the 80-86 F-series forum just above here, you'll look under the sticky at the top and find DSII swap information:

Ford Truck Enthusiasts Forums - View Single Post - The '80-'86 Sticky - Tech Tips & Tricks

It's entirely possible and financially feasible to make your own wiring harness for the DSII ignition, and the swap itself is straight forward and plug and play. Like you said, with junkyards and such down here, a DSII swap can usually be had for less than or right around $100.

You could make a wire harness with the correct ballast resistor, buy a new coil, distributor, and ignition module, and plug it all in using the information provided. And, you can still run the stock feedback carb until you can find a non-feedback model or some other 1bbl like a Holley or an Autolite, or an early YF.

Either way, let us know if you have any more questions. We're here to help.

 

The reason most go with a pre-feedback carb is because the feedback carb is calibrated for the emissions equipment present in the system. Also, you can't tune and adjust the settings on the carburetor (such as the idle mixture) because there are computer controlled solenoids where screws used to be. That sort of thing.
It'll still work, it's just not ideal.

 

FYI: You can get the distributor, with cap adapter, cap, and rotor, the DSII module w/blue grommet, and all 3 connectors needed for the DSII conversion form Rock Auto. You choose which brand name you want. All new for $125-150 delivered. Best Wishes...jack

 

No ping..no black smoke..no backfire it starts and runs like a rocket. First time every time. It sat in driveway after 3 weeks of sub zero temps jump in an started first crank.. ran in high idle for 1 minute..kicked it down and idled like a charm. Put it in drive and went for a spin..no problem what so ever. Starts and runs the same in the summer. Thats the part that confuses me . From what Ive read after all iv done it should run like crap..but its not. I did have a diseling problem at one point but after ripping out a few more componants it was gone so have no idea how I solved that.
　
ballast resistor
From memory I though I didnt need a resistor ? Not sure

Jack

Well that sound too good to be true can you direct me to the wireing harness I need as I cant find it and had no idea I could purchase one. As for the other components I will try my local NAPA as ordering from the states is very expencive with duty taxes shipping ect ect. Im in Canada by the way.

If anyone has suggestions on what they would purchase from NAPA for this project please let me know. Would like parts made in the USA if possible not not sure how to tell the differance. This is just to important to rely on chinese made componants and am more than willing to spend extra money to do it right the first time.

Thanks again guys.

 

You really can't argue with that! Maybe you don't need a carb for the time being if it's running how it is. Get your ignition in check and leave the carb alone unless you find you're getting terrible gas mileage.
　
I keep hearing something about the resistor coming up whenever the wiring harness is discussed, but as far as I know, it's built into the ignition module. I've NEVER seen a resistor in the wiring harness, or anywhere along any of the plugs, etc. Neither my stock '81, or the '84 I converted to DSII, has a resistor. I don't know why this continually comes up, unless a few years didn't have it in the ignition module.

As far as I know, it's not available for purchase. However, the wiring harness is simple enough that you can make your own with some custom plugs and wires from an electronics store.

Too many components in the US are from China as well.

If you want to order the stuff, just get a distributor, coil (aftermarket performance is fine), and ignition module for a 1980 Ford E-150 with a 300. That'll get you what you need. Generally, there are two ignition modules available. A cheap (~$30) and an expensive (~$80) one. You can probably guess where each is made...

 

I wonder if all of his emissions equipment was in perfect shape, and then, when he ripped all of the feedback equipment off and disconnected various components, the computer didn't have control over the carburetor and it's locked in right where it should be? Maybe the computer didn't have time to lock the fuel mixture in rich?

If you really want the DSII swap to be plug and play, and look factory, you'll have to find a donor vehicle to pull the wiring harness from.

 

Maybe you don't need a carb for the time being ...unless you find you're getting terrible gas mileage.

Gas mileage is really my biggest concern with gas at $1.32 per ltr now ..and will reach $1.50 in the summer once again envey you guys in the States . Not to mention just would like the motor running at full potentiel. But I shoot no **** when I tell you it runs like s rocket . No ping ..backfire..black smoke ..etc

I was pissed when I found high idle adjustment but no idle adjustment. Till I took carb off only to find the idle adjustment screw capped ..uncap it and made adjustments yes it was functional . Also a slot screw adjustment of some sort at base of carb that I asumed was a mixture adjustment.. may have played with it a bit did I get lucky ? I didnt think it would have a idle adjustment screw . Possible they took a regular carb.. adjusted as nessisary to make a feedback and blocked off other options ? [ iidle and mixture screws] If in fact it is a mixture screw. Sure would have saved a lot of money..I dont know. I will take a picture of what I think maybe mixture screw at base of carb on next sunny day.

.resistor coming up whenever the wiring harness is discussed, but as far as I know, it's built into the ignition module.

By memory I think and hope thats right

As far as I know wireing harness is not available for purchase

I searched for an hour before finding out this was misinformation ..unless poster can prove me wrong.
Will look into making my own..

I will make no moves untill i record gas milage this summer and see if it runs well after a 4hr highway drive . So I can compare before and after mpg..power..etc and post results. In pevious post I mentioned starts and runs well in summer..my mistake..I only got this van in November but it ran very well on a few warm days we had and took it for a spin on highway..perhaps things will change in the summer heat and will run like its supposed to [crap] but somehow I dought that.

the computer didn't have control over the carburetor and it's locked in right where it should be? Maybe the computer didn't have time to lock the fuel mixture in rich?

I dont know Im still scratching my head trying to figure out why this motor is running the way it is . Roads will be dry this weekend and will take her on the highway for a test run . And try to take a picture of what I think maybe a mixture screw . Im surpized it even has a Idle screw considering it was computer controlled and as I said it was capped off.
Im so confused..lol

 

This is a feedback carburetor. If it doesn't look like this (the big, metal solenoids on it) then someone's already done part of the work for you and put on a non-feed back carb. On the feedback, you have to remove the solenoid to be able to access the idle mixture setting. And even then, it's still difficult to turn since it wasn't meant to be done by hand.




If there is no idle RPM adjustment (just the high idle adjustment) it's possible the screw is just missing. It should be there. Although, I can't imagine it being able to idle at all without it. They're side by side on the back on the driver's side of the carb next to the valve cover. Not the most convenient place. The one that presses into the carb body is the idle, and the one that presses into the linkage is the high idle.



Either way, if you already have the non-feedback carb on there, you have the easy part ahead of you, which is just swapping the ignition. You'll love the results. Hopefully you can track down the wiring harness. I need to grab all the ones from my local junk yard next time I'm out there.

 

Thats funny I figured I may be asked if its a FB or not after posting possible fuel mixture screw..my mistake..took a look and there is none just the fast idle .. and idle that was capped off as I mentioned . So yes I have those options .
　
On the feedback, you have to remove the solenoid to be able to access the idle mixture setting. And even then, it's still difficult to turn since it wasn't meant to be done by hand.

I have removed that solenoid and capped it. [ if thats the cone shaped device with the wires to a connector leading to right side of photo ] Theres a mixture screw in there ? No matter will not touch it .
　
Hopefully you can track down the wiring harness. I need to grab all the ones from my local junk yard next time I'm out there.

Drive that nail deeper into my chest..I can get nothing here in Canada .
Your a senior member here if you can get me a harness [no tack] will pay $50 + shipping and origanal part price [ if they even find it in your underpants Big Bronco ] lol . You will get cert cheque before you mail .

Gotta ask..that photo of you buried to the axles..did you make it out ?