Hose ID Help

[SFBullnose]

I had sometime to dig into the truck today. Got two new coolant sensors in, and did some cord management.

I found this hose, with some kind of valve in it coming off the air cleaner.

Any help on what it is ? I couldn't track it down in the haynes manual.

Thanks!

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27683&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27684&stc=1

[SubGothius]

I think that hose supplies air to the secondary-air induction valve on the exhaust, which reduces emissions by introducing oxygen to the exhaust stream to help consume unburned hydrocarbons.

[xboxrox]

On my 1986 truck that hose connects to a Reed valve & there is a pleated air filter attached to the outside of the air cleaner case under a small metal cover held on with screws...
Crankcase Breather Element http://https://www.rockauto.com/en/catalog/mitsubishi,1986,mighty+max,2.6l+l4,1206593,exhaust +&+emission,crankcase+breather+element,4932 (https://www.rockauto.com/en/catalog/mitsubishi,1986,mighty+max,2.6l+l4,1206593,exhaust +&+emission,crankcase+breather+element,4932)
Piece # 1
27685

[SFBullnose]

On my 1986 truck that hose connects to a Reed valve & there is a pleated air filter attached to the outside of the air cleaner case under a small metal cover held on with screws...
Crankcase Breather Element http://https://www.rockauto.com/en/catalog/mitsubishi,1986,mighty+max,2.6l+l4,1206593,exhaust +&+emission,crankcase+breather+element,4932 (https://www.rockauto.com/en/catalog/mitsubishi,1986,mighty+max,2.6l+l4,1206593,exhaust +&+emission,crankcase+breather+element,4932)
Piece # 1
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27685&stc=1


Thanks for the help you guys! Yes, so I'm seeing the reed valve, maybe that's the piece broken in the hose. Will need to work or cut that out maybe and replace the hose.

Good call on the crankcase breather filter! I didn't even think to look for that.

I'll need to maybe see if I can track down or retro fit that valve. The barb is definitely a bit chewed up on the air cleaner.

[SFBullnose]

Pulled the hose off today and worked out the connector. It looks like it's a Dorman 5/8th to 3/4 heater hose connecter. The conical piece is a mystery to me. Is that the one way valve ? Any harm just hooking it back up with the hose connecter ?

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27687&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27688&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27689&stc=1 http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27690&stc=1

Thanks,

[FMS88]

Looks like something a PO improvised. Definitely not stock. The hose should just slip onto the large port on the back of the air cleaner. Is the other end of that hose connected to the reed valve? (The valve looks a bit like a top hat.)

[SFBullnose]

Looks like something a PO improvised. Definitely not stock. The hose should just slip onto the large port on the back of the air cleaner. Is the other end of that hose connected to the reed valve? (The valve looks a bit like a top hat.)

Thanks for heads up. Yes, it does run to the reed valve. So, I'll just put it back on the nipple on the back of cleaner. I wonder why the hose adapter was used?

Appreciate it!

http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=27692&stc=1

[SubGothius]

I wonder why the hose adapter was used?

Your guess is prolly as good as anyone's. The only sound reason might be if the one-way reed valve failed somehow, allowing exhaust gases to pass the valve and enter the intake via the hose. To check this with the engine running (might also need to be fully warmed up?) there should only be a pulsing vacuum sucking air into the valve via that big hose, no "blow back" pushing any gases out of the valve.

That aside, we can only speculate what the PO might have been thinking. Maybe they heard something about "smog pumps" robbing HP, but that only applies to actual belt-driven pumps injecting air into the exhaust under pressure, rather than passive air induction setups like these, and those pumps only rob like 1/2 HP or so anyway. Or maybe they mistook that secondary-air induction setup for EGR and thought they might improve performance, mileage, or reliability by disabling it.

BTW speaking of EGR, its purpose is not to "reburn residual hydrocarbons in the exhaust" as many think. Rather, EGR reduces combustion temperatures by diluting the intake charge with already-combusted inert gases from the exhaust that don't significantly affect the fuel:oxygen ratio, thereby reducing NOx emissions that are formed at higher combustion temps.

[SFBullnose]

Your guess is prolly as good as anyone's. The only sound reason might be if the one-way reed valve failed somehow, allowing exhaust gases to pass the valve and enter the intake via the hose. To check this with the engine running (might also need to be fully warmed up?) there should only be a pulsing vacuum sucking air into the valve via that big hose, no "blow back" pushing any gases out of the valve.

That aside, we can only speculate what the PO might have been thinking. Maybe they heard something about "smog pumps" robbing HP, but that only applies to actual belt-driven pumps injecting air into the exhaust under pressure, rather than passive air induction setups like these, and those pumps only rob like 1/2 HP or so anyway. Or maybe they mistook that secondary-air induction setup for EGR and thought they might improve performance, mileage, or reliability by disabling it.

BTW speaking of EGR, its purpose is not to "reburn residual hydrocarbons in the exhaust" as many think. Rather, EGR reduces combustion temperatures by diluting the intake charge with already-combusted inert gases from the exhaust that don't significantly affect the fuel:oxygen ratio, thereby reducing NOx emissions that are formed at higher combustion temps.

Thanks SubGothius!
This is helpful information. It's good to try and understand the high level view of the system. I have a feeling it may have been something the PO did to disable the system. The car had been running with an antique plate, which doesn't need an emissions inspection here.

[FMS88]

The reed valve only opens shortly after start up and during deceleration. An easy test with a warm engine is to remove one end of the large hose. Rev the engine to ~3000 rpm and release the throttle quickly. You should hear a loud pulsing noise from the reed valve until the rpms drop to near idle speed.

If no noise or you hear it at idle, the valve is bad. It's subjected to combustion by-products so it degrades internally. Those I've disassembled are either clogged or very corroded inside.