Lets talk 3fe Desmog. (1 Viewer)

[ward93]

This is for some deeper discussion for me as I under stand how to do it. and have the desmog guide for the 3fe.
1. what I know, the 3fe is designed to run desmoged, I will get better power, smother running, and possibly better over all mileage but this is debatable and not really important.
2. I have a good idea how to do it and what parts are needed. per the desmog guide floating around the forum. if anyone wants it ill be happy to send it to you.

what I need to know/ want to discuss
1 is there really a reason to remove the smog pump if its not connected to anything.
2 how long does it really take for the ecu to learn, and how quickly will it forget when battery is disconnected.
3 why are most so scared of it
4 is there any real reason not to other than if you live in an area that tests emissions
5 is it possible or worth it to track down a non us ecu, or are there any better after market ecus that could be used and maybe use a mas air flow meter vs the afm which is impossible to find new and when you can its outrageously expensive.

 

[ward93]

oh also I also intend to remove the cats before doing anything.

 

[brownbear]

I put two BB gun pellets in the vacuum lines off the top of the manifold and the egr was then non operational. It was a huge improvement to the running of the truck.

If you don't have air care or inspections done, I would remove all the air pump and such too. I changed the belt to a shorter one were the air pump wasn't being run, and with the BB's that was my de-smog, and the MPG increased and it was almost immediately changed. I do not re-call an ECU learning period.

 

[cruisermatt]

Removed all the smog system from my 3FE when it had 280K miles, and it ran the same before and after. on the next two motors (one with 5K mile and the other currently at about 6K) neither have any smog components either. Stock USA ECU is fine, only possible issue is if you have a California ECU it might want to see a reading from the EGR temperate sender? I don't actually know though.

Nice benefit of removing the smog pump is that you can put a second alternator there.

 

[red66toy]

Keep the cats, or get a new one (route the exhaust to just one new one instead of two little ones), its good for everyone. As for the rest of the parts, if they are in good condition keep them on hand in case you sell it and someone needs to convert back. Or sell them to some poor California cruiserhead who has to comply with the regs. I plan on desmoging my 3FE, space for a second battery is a plus, and the elimination of the dreaded smog pump seize.

 

[ward93]

So on the bb fix do u have a pic of which exact lines? I would try that to see

 

[ward93]

That sounds sketchy but since I'm gonna desmog I'll try it though

 

[Kleatus]

I pulled everything off mine the other week because the air rail had melted the wire harness and was causing a lot of hate and discontent. While I had the upper intake off some things went away.None of it worked right before so no change in running, power, mileage, etc. As others have noted, you pick up a lot of space without that stuff in the way. Yes a CA ECU will throw code 71 when the EGR isn't working. Mine did before and it still does. I haven't fixed that yet - but you should be able to replace the sensor with a resistor of the correct value to keep your CEL off.

Removed all the smog system from my 3FE when it had 280K miles, and it ran the same before and after. on the next two motors (one with 5K mile and the other currently at about 6K) neither have any smog components either. Stock USA ECU is fine, only possible issue is if you have a California ECU it might want to see a reading from the EGR temperate sender? I don't actually know though.

Nice benefit of removing the smog pump is that you can put a second alternator there.

 

[Output Shaft]

That sounds sketchy but since I'm gonna desmog I'll try it though

Some of the emissions components on the 3F-E are actuated by engine vacuum. The vacuum is the force that pulls a diaphragm that makes something move.

The vacuum travels through the thin black vacuum hoses to wherever. When a ball bearing (3/16" for oem vacuum hose, 5/32" for silicone vac hose) is jammed in a hose, the vacuum is blocked which disables it's attached component. Blocking certain vacuum hoses is how some emissions components are disabled.

(BTW, an air gun bb is too small)

 

[sbelinge]

I took everything off my CA '89 62 except the air rail (that will come off this summer). As many have mentioned there was no change in performance or another metric as far as I could tell. I got the code 71 for a while but I fixed that and it no longer comes up. The extra space with the air pump gone is nice plus if you're not using it it seems kind of pointless to keep it installed. I did keep all the parts "just in case" that may be pointless too. The reason I desmoged was because my air pump started to go bad and I figured what the hell, I'll just gut it.

 

[SteveH]

4 is there any real reason not to other than if you live in an area that tests emissions

If this passes, many states/localities may restart testing (even if ozone is more of an evap. thing than a tailpipe thing): After Years Of Bipartisan Opposition, EPA May Reconsider Strict Federal Ozone Standard

 

[ward93]

I live in Memphis and they are too broke so I'm not too worried but will keep all of my parts, though mine are so s***ty I'd probably just spend the money on all new if I had to do that and may buy in advance in case they stop making the parts. But more than likely I'd just get it registered as anteque

 

[jigglebear]

I pulled everything off mine the other week because the air rail had melted the wire harness and was causing a lot of hate and discontent. While I had the upper intake off some things went away.None of it worked right before so no change in running, power, mileage, etc. As others have noted, you pick up a lot of space without that stuff in the way. Yes a CA ECU will throw code 71 when the EGR isn't working. Mine did before and it still does. I haven't fixed that yet - but you should be able to replace the sensor with a resistor of the correct value to keep your CEL off.

strip back the insulation from the two wires going to your egr temp sensor. twist the wires together and heat shrink over the exposed wire. this will get rid of your 71 egr fault and the check engine will go away. I just completed my desmog and my 80 runs much smoother. idle better and sounds more healthy at idle. no report on mileage yet but I have heard up to almost 3 mpg gain. whether that is true or not im not sure.

 

[62LostInMn]

Did you guys who desmogged make any changes to your timing? Or is it purely component removal?

 

[ward93]

I'm wondering this as well

 

[cruisermatt]

Stock timing.

 

[62LostInMn]

If I wanted to do a desmogged "test drive" could I just pull and plug the vacuum lines at the EGR and disconnect/plug the air pump line to the air rail?

 

[cruisermatt]

If I wanted to do a desmogged "test drive" could I just pull and plug the vacuum lines at the EGR and disconnect/plug the air pump line to the air rail?

That's what's known as de-smoging buddy.

 

[brownbear]

So on the bb fix do u have a pic of which exact lines? I would try that to see

I know there is a thread here on it. But I am going to explain it the best I can..

On the top of the motor is two rubber hoses coming out of the manifold. They suck, meaning vacuum. If you put a BB into each one, it stays there as it's too big to go into the metal spout that the rubber hoses connect to. These hoses slide off the metal and you put the BB into the hose. The hose is like 1/8 inch inside. Really little.

These two hoses feed the EGR with actuating vacuum. Without the vacuum the EGR stays closed and the engine runs so much better.

Why feed your engine old exhaust?

Now the air pump is a piece of s*** but it can stay on there, you just get the shorter belt that the De-smog threads call up. The air pump doesn't make the engine pollute less in any way. All it does is add Air to the exhaust so the tail pipe reading is lower. Dilution is not the solution for pollution.

 

[62LostInMn]

OK - you got me Captain Obvious...
I suppose the only "maybe" is if the EGR is stuck partially open... We'll give it a try and see what happens.