Hello, I'm a new member here and I recently purchased an 86 F150 with a 300 i6, and I'm hoping to fix it up myself as much as I can. I've spent some time digging around on this forum, and it will be very helpful!

To my question, the PO installed a new carb, and the EGR has been deleted, no smog pump, and the little vacuum hoses that connect to everything are either broken, cut, or plugged. I've seen several threads about deleting the emissions all together, and I would love to do this so I can clean up the engine bay. All of those hoses and disconnected wires are just in the way. Can I just pull them all out? What about the solenoid that they connect to that is bolted to the back of the engine? Are there any other parts that can come out? I've included some pics for reference.

Ain't she a beaut?!

EGR is gone

Solenoid

MAP sensor? There is a hose from this that is cut.



The truck runs great as it is now, but I obviously don't want to screw anything up. I'm fairly handy, and I do most of the general maintenance on all of my vehicles, but this is my first time with an older vehicle like this and I want to learn on it.

Any help is greatly appreciated!

 

Give us a pic of the overall engine compartment close up are great but they do not show the whole picture..

Your truck had a feedback system with a TFI EEC-controlled ignition system. So we need to see what is left of it and if you have a feedback carb still or not.

 

As Matt said need one of the carb farther back showing it and 1 of the dist. to see if it has a vacuum line to it or not, thinking not.
One or 2 of the over all is nice of the engine bay too.
Dave ----

ps welcome to FTE

 

Here are some overall pics showing the carb and distributor.

Thanks for the help!

 

I've spent the afternoon installing new conduit to clean up the rats nest of wires and hoses. Looks a lot cleaner, which is what I'm going for. Just trying to clean up the mess left by the PO. Replaced the PCV valve and hose (cracked and falling apart) and the truck is running noticeably smoother. The only vacuum line on the diagram under the hood that is actually connected to anything is the red one that goes to the T connector that connects the intake manifold to the MAP sensor. All of the other ones are either cut or plugged. I'd love to just pull them all out if possible.

 

I see a TFI ignition module on your distributor, which means your ignition system is likely crippled by a non-feedback carburetor.

 

As mentioned you have a TFI distributor. Someone has replaced the feedback back carb with a knock off YFA not ideal but will suffice for the time being.
Since the EEC system is mostly missing the TFI system will have defaulted to a safe timing curve. Translation less power and burning more fuel.

You have a lot of other issues going on that need to be adressed. The most critical is a complete lack of PCV system that leaving the crankcase open to the atmosphere allowing it to be exposed all kinds of debris.

You need to address that PCV system (or lack thereof) first before doing anything else.

The Front hole should have the fresh air feed for the PCV system. (See first pic below circled in red). Since this is long gone and sourcing long-obsolete OEM is a PIA the alternative is to just install one of these guys.
https://www.summitracing.com/parts/mil-85681

That has the feed side of the PCV taken care of.

Now you need a PCV valve This is the guy you need https://www.summitracing.com/parts/m...-150/year/1985
This will go in the back hole in the valve cover (See First pic below circled in blue)

That will need connecting to a vacuum port you will need some vaccum to do that here is that https://www.summitracing.com/parts/dac-80369

You have an open Port at the base of the carb (for the pcv no doubt) Plumb the line to this port (Second pic below circled in red. )

Until fix the PCV system there is NO point doing anything else as you will not be able to get the engine to run right or even know if anything you are doing is working properly.

I would advise against driving the truck until you get this stuff fixed.... as you are running the risk of engine damage.

 

Matt,
He has the rubber grommets for the PVC at the rear of valve cover and the fresh air one at the front.
He can get the PVC from any local parts store.
The hose has to be SMOG rated going from the PCV to the vacuum supply as it will have oil vapor going through it and will get mushie if normal hose it used.

Now in the help area of the store he can find a 90* ELL to fit the front grommet to fit a hose on that will go to the air filter assy.
In the air filter assy. there should be a small filter assy help to the side with a clip the hose hooks to.
The factory used an adaptor between the filter and the hose that you cant get.
In my case the hose fits on the filter nib and has been ok or hit a junk yard for one.
I have a different shape filter on my 81 F100 but it all works the same way.


Once you have the PVC taken care of we can work on replacing that TFI dist. for one that will give you adjustable timing, more power and better MPG.
Then we can remove that mess of wires & un-used vacuum lines.

Little at a time it will get there.
​​​​​​​Dave ----

 

Or he can just order it all from the links I provided in the post for under $30... Or match the same parts at the parts store...
And thanks for stating the obvious about the PCV hose, Check the linked item and read the description.....
And to go from the valve cover to air cleaner for the PCV feed will require 2 fittings plus a hose plus filter/holder plus the retention clip. The far easier, cheaper, and better solution is to just drop in a push in PCV breather cap as linked and be done with it.

 

Thanks for all of the replies. I do have a PCV valve, I had just taken it off to replace it and the hose. You can see it in the last pic peeking up behind the air cleaner. I'll get a breather valve for the front today.

I don't know very much about the TFI dist., feedback vs. non-feedback carb, etc. I'll do some research in order to understand how all of this works together. Any resources to point me in the right direction? This is a project, so I expect to have to change some of this stuff out. Would a new feedback carb be in order?

 

No need to do the research we can explain it right here.

The feedback carb system utilizes Ford's EEC (Electronic Engine Control) system. The system on your truck adjusted the fuel/air mix and ignition timing in response to signals from various sensors on the engine OS sensor, MAP, TPS, coolant temp sensor, and engine RPM.
The system was a bodge from the get-go and was a cheaper solution than fitting a proper port fuel injection system. Many of the components that make up the system are long obsolete so resurrecting an early Feedback system can range from difficult to near impososble.
Furthermore the system never really worked well and could provide very inconsistent operation and was not overly reliable. In short, it was a cluster from day one.

By far the most common solution is to remove the EEC system go to a non-feed back carb (like you currently have) Back step the ignition system from the EEC controlled TFI to the earlier duraspark system.
Most of this is strait forward.

Ideally you want to remove all traces of the Feedback system to clean up the engine bay and not have a bunch of dead wiring all over.

The group here has walked many people through the process so you are not the first to back to a non-feedback carb and Duraspark ignition.

There are a few options that on how you do it and what components to use also. But sweat we have you covered either way.

 

To put it in simple terms, you need to swap the distributor out. You have two choices;

1. Go back to the Ford duraspark II system. Get a older duraspark II distributor for a 300 six, a duraspark II ignition module, and the short harness that goes between the distributor and the module. You can get the distributor reman from the parts store. You can get a new module from the parts store. The hard part is the harness between the dist and the module. Painless sells this harness, but it's not cheap and not very painless either. matthew has put out links to the plugs so you can build your own. If you have a junk yard that has some old Ford/Mercury vehicles, you can get this harness from any car or truck, any engine. You can get a used motorcraft module from any older car or truck any engine, as long as it has the blue plastic where the wires come out. If you get these parts rounded up, once you get the distributor placed correctly in the engine, there is virtually no wiring, it will plug right into the wiring harness you have already. They had other engines that used the duraspark II system, and your truck uses the same harness.

OR

2. Go to amazon or ebay and get a aftermarket HEI retro fit distributor. They make them for your engine. Drop it in and hook up one wire from the ignition, and you are ready to go. The module and the coil are all built into the distributor itself. You can do the research and pick the best one, there are different brands and some may be better than others.

I would make the distributor swap a project and get the engine running. The I would make pulling all the other wiring out another project afterward. There is a bunch that leaves.

 

I did read about the hose but wanted to point it out again why it has to be safe to use with oil vapor.
On the fresh air to the PVC it depends if you want it looking stock or aftermarket bling.

I am going to say to retune it to a working feed back system will take a little more than just putting a feed back carb back on. All the wiring from computer on out to the sensors to what the computer controls has to work 100% or it goes into limp mode, not good for power or MPG.

You only need to replace the dist. with a non-feed back one.
The easiest one to use would be the HEI for a Ford 300 you find on Ebay. Drop it in a few wires and done.
If you go for a DSII (pre feedback 82 and earlier) youneed the dist. the IGN box and the $$ harness from MSD.
If you have a junk yard that has older Fords you can get the DSII parts from there or order the parts through a local parts store.
Dave ----

 

Thanks, you guys are awesome! Swapping the distributor seems like the way to go for sure. Is this the one you are referring to? https://www.ebay.com/itm/19188053533...QAAOSwQupXWUHx

The truck is running great as it is currently, so I'm sure swapping this out will be even better. It starts immediately and runs smooth. It was a 3 hour trip home with a mix of mountains and 70 mph on the interstate with no issues.

This "clean up the engine bay" post has been great, glad you guys enlightened me on the carb/ignition issue.

 

Yes, that is one of the distributors you could use.

What's happening, your TFI distributor is empty except for a pickup and wheel inside. This sends a signal to the TFI module mounted to the outside of the dist. At the same time it sends this same signal to the computer. The computer looks at all the sensors and engine conditions, and then sends back a signal to the TFI module to advance or retard the timing. The TFI then fires the coil at the right time.

Now that a bunch of stuff has been disconnected,, the computer can't make good decisions anymore on the timing. The TFI has a failsafe to keep the engine running, the TFI will fire the coil by itself at base timing, which is wherever you have it set at. The sticker on the radiator usually calls for 10 degrees BTDC. So your engine runs, but only at 10 BTDC all the time.

These older distributors and the retro-fit distributor you looked at have mechanical weights and a vacuum advance unit to advance the timing according to engine rpm and engine load. That's why you need to change to one of these to complete the conversion and get the max power and fuel mileage from your engine.