There may be a capped port and if so then they may build it to cover both non-feed back & feed back.
Do the dist. and use your carb and see how it works for you.
I was given a box of carbs pulled apart and 1 is a feed back I should look it over to see if it adjust the same as my non-feed back carb.
If so and you find the MPG is poor we can try and lean it out.
This Ebay carb was way lean by my air fuel ratio gauge so I had to make it richer. I have a little more testing but I think it is pretty good where it is.

FIY on the air filter PCV filter if a motor has a lot of wear it can have a lot of blow by that the PCV can not handle and the blow by will push into the air filter assy filling it with oil making a mess

As a test you can pull the hose off the filter or valve cover and with the motor running and up to temp use a sheet of paper and see if it gets sucked to the hose or cover. If you the blow by is normal the paper should stick to them. If it get blown away and you see oil vapor coming out you have to much blow by and more testing might be needed but most of the time it needs a rebuild.
Dave ----

 

I also just discovered the spark plug thread chaser. Best $7 I spent at NAPA. Could not figure out why the plugs were such a you know what to get out or put back in until running that chaser though. This last time took the breaker bar to get them out, almost all the way.

 

Can you have good compression on all cylinders and still get air flow out of air filter line by blowby?

 

Your compression will continually fall through the years of use, and the blow-by air will continue to increase. "Good compression" means different things to different people. But I would go ahead and get a new PCV valve for your application. It should rattle when you shake it, and it should suck on your finger with the engine idling. Even so, sometimes people put the wrong valve in, so make sure it's the right one with the right flow.

When the engine is brand new and broken in, you can have the PCV valve installed, and put your hand over the line going to the air cleaner and eventually feel suction on it. Through the years of use this will go lower and lower, even though the engine still runs ok. Like was mentioned, the engine will eventually get so worn that you will have some air flow into the engine with it running. You may get some deposits and a little oil smoke up in there when you turn it off, that is normal.

 

Well, after a couple weeks removing a large old oak and a huge pine from my pond, I am back on the Ford project with one detour, I have to fix my wifes 2002 Chevy Suburban. I need to chase the threads on the downstream oxygen sensor boss and it seems to be the exact same size at a Ford large thread spark plug. Can someone confirm that the thread diameter and pitch for the spark plugs in a 1985 300 cu in 6, is 18 X 1.5? Thanks. I have a Ford thread chaser for the big plugs, but I have no metric thread gauges to be sure.. .

 

Yes, all oxygen sensors are 18 x1.5 mm thread.

 

Thanks. I removed the sensor, but only half the threads came out, hoping the chaser will cut new ones, or at least enough the new one will screw in fully.

 

For cleaning up the threads, I highly recommend an expanding back tap such as a Powerbuilt 691381:

https://www.powerbuilt.com/products/...ir-tool-691381

The outer diameter collapses to fit past the damaged threads. Once expanded to fit, it engages the undamaged threads for alignment.

 

I found a 18X1.5 taper tap, but this might be worth the 40 bucks to cut it from inside out. Thanks for that link, that is a new one for me.

Hey, I just ordered it and used a Powerbuilt Tools discount code and saved 15%, so saved a couple bucks and will 'get r dun' right.

Thanks again for that info.

Charlie

 

The backtap is a very slick tool. It's not really an issue repairing threads for an O2 sensor, but the design pulls the chips out as you go. If working on a spark plug hole, you don't want to force debris into the cylinder. Adding grease to the threads helps catch debris with either style of tap, but moving the chips in the right direction is a huge plus.

 

If you have room for a shop vac crevice attachment up next to the work you can suck some chips free.

 

That's a pretty slick tool, surprised I've never seen something like that. But I do have a normal tap for that. Had to clean the O2 threads once years ago.

 

Hoping it will clean the threads. The sensor started out OK, but then stuck, thought maybe a little crap on the inside edge was stopping it and would break off. When I got it out, there should have been about 6 threads on it, there were 3, and you could see where what was a thread was folded flat onto the sensor, and inside, you see 3 threads, then what looks like it was never tapped. Hoping it will clean up with the chaser and not need a helicoil.

 

Success! Started this project in November last year, ordering an generic HEI distributor, extra module for it, and new plug wires. Since I don't have a covered area, the weather was the main reason for the time it took. I rebuilt the Carter YF1_ feedback carb, removing the feedback solenoid and covering the opening with a metal plate and gasket. Removed a couple other things, the idle solenoid, the TPS, my rebuilt kit did not have the proper gasket for the carb to mounting base, so made a new one, and did not punch the hole in it that seemed to be associated with black, ie, exhaust, even though exhaust was removed from the carb circuit, did not want the extra hole to affect vacuum if it might. I removed and blocked off the EGR valve port with a 3/8" aluminum scrap bar, reusing the gasket and new high temp gasket compound. Removed the line from the gas vapor canister, plugged the air lines frrm the air pump, removed the air pump. There is a 5 port vacuum manifold on the EGR valve/carb base section, and it feeds the the PCV valve that I kept, the brake booster, and I added a line to the new distributor for advance., plus the vacuum line to the air filter, it does not leak, but then again, it does not operate the baffle. I found all of those vacuum line solenoid valves bad, they did read continuity for a good solenoid, but none of them would pull in, and all the vacuum paths were open. When I got done, there were only 3 wires in that bundle going to the pollution controls that were left, and one of them went to the AC compressor, but the AC has not worked for decades, maybe I will get it going one day.

With motor manually timed to 0 degrees and #1 on TDC, that is after finding the correct timing mark which was just a hair wide, and marking it with white paint, fired it up with a shot of starting fluid. Ran for a bit then quit. Needed to open the fuel line to the carb, and crank it to let the mech fuel pump get primed and flowing, after that, started up fine. Maybe I should replace that pump, it has been on the truck since new, 410,000 miles ago. This is a truck that has not been run since October last year. When I put the vacuum line on the distributor, it went to a perfect 10 deg. BTDC. It was running a bit high on idle, but then realized that one of the ports on that vacuum line manifold was open, and it was one of the bigger ones. Put my finger on it, and settled right down.

The EEC is still in the truck, and powered up. Of course it is not doing anything but I noticed that the engine temp sensor went to it, so thankfully the temp gauge is still working as are all the instruments. I rolled up all those un-needed wires and secured them under the hood, and got some new plastic loom material to run the remaining wires where they needed to go.

Here is the real kicker. The TFI on the old distributor shown in my 48 year old Haynes Service manual, shows the wiring and color codes, it actually shows a couple different pin outs and colors, none of which were like mine. It clearly shows +12 on the whit/blu wire in the #1 spot. That was all wrong, none of that TFI info seemed correct. I found +12 from the ignition switch, what is needed for the new distributor, on the 4th wire in, a Yellow wire. Confirmed that it did not go to the EEC or any other part, by reading the volts on that wire, and putting a 6 ohm resistor to ground, and it held 12 volts, a bit less due to wire loss, but no resistor wire or other component in line with it, and double checked with battery disconnected and reading direct from the yellow wire, through the ignition switch, to the battery.

Remains to be seen what gas mileage I will get, may have to get an non-feedback carb in the long run, but right now it is running smooth and throttle response is very good. I don't know if Biden and the Democrats will still allow gasoline, but as long as it is available, this truck will continue to run. Then, maybe get an adapter plate for a jet engine starter motor to transmission, put a bunch of 12 volt batteries in the bed, a giant rheostat for a throttle, and convert it to electric.

 

Good to know you got it running again.

On the dist. and using manifold vacuum as you saw bumped the timing from 0* to 10* BTDC
Thing is you are at full vacuum advance when on manifold vacuum.
So vacuum advance is not controlled by motor load like when on ported vacuum from the carb.

This is not a bad thing and people have pros and cons about both and the only way to know what the motor likes is to try both.
As for starting at 0* timing then manifold vacuum I would try bumping it up to maybe 2* to 4* as long as you dont get pinging.
Dave ----