EFE Emission question
Thread Starter
Pro
Joined: Apr 2002
Posts: 677
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From: WInnipeg Mb
EFE Emission question
Can i remove the EFE actuator with out hurting how the car runs if i have stock manifolds on right now? What all needs to be taken off to do that? IS it worth it to take it off or wait until i put headers on then take it off
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: EFE Emission question (Justin79-L-82)
Removing the early fuel evaporation (EFE) actuator will render the heat-riser valve inoperative. And that will slow warm-up as the choke will be effected. Why bother removing it at this point? I assume that you will go to an electric choke when the headers are on? Don't throw away that actuator. They are very hard to find and expensive when found.
For the interest of other readers, this is the actuator.
For the interest of other readers, this is the actuator.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: EFE Emission question (Justin79-L-82)
With headers you will not have a flow of hot air on start-up through the intake manifold. The EFE actuator keeps the heart-riser valve shut by vacuum and backs up hot exhaust through the intake manifold cross-over induction system to aid quick warm-up. That is where the heat pipe for the choke sits. When the coolant in the engine reaches a temp of 120F, the thermal vacuum switch (TVS) located in the neck of the thermostat housing shuts down the vacuum to the EFE actuator and the heat riser opens. All of this works in conjunction with the choke and the vacuum-operated heat stoves on the air cleaner horns. Or.......just replace the divorced/heat style choke with an electric one to avoid all of this confusion seen below;) .
[Modified by paul79, 3:29 PM 5/26/2002]
[Modified by paul79, 3:29 PM 5/26/2002]
Thread Starter
Pro
Joined: Apr 2002
Posts: 677
Likes: 0
From: WInnipeg Mb
Re: EFE Emission question (paul79)
wow, i have no idea what you just said :D I'm putting on the weiand dual plane action plus and the Xe262 cam... after that i'm putting on headers and true dual exhaust.. does that mean i have to convert from divorced heat riser choke to electric choke because the efe will be removed when i make the change? How hard is that to do and where can i get these kits for it?here's my engine now
[Modified by Justin79-L-82, 9:05 PM 5/26/2002]
[Modified by Justin79-L-82, 9:13 PM 5/26/2002]
[Modified by Justin79-L-82, 9:05 PM 5/26/2002]
[Modified by Justin79-L-82, 9:13 PM 5/26/2002]
Pro
Joined: May 2002
Posts: 726
Likes: 0
From: Petaluma CA
Re: EFE Emission question (Justin79-L-82)
The picture is clear, but to see the setup, it needs to be the other side with air cleaner off...? Anyway, why take efe/heat riser off? My 81 350 with factory headers has an efe/riser bolted close together and cannot be purchased separately. $95 at ZIP. And if you do take efe off, be sure the heat riser and exhaust is wide open all the time?
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: EFE Emission question (Justin79-L-82)
Justin,
I have never used headers so will pass this topic on to those who have converted. Sorry I cannot take this further. Many members have and I am sure you will hear from them.
[Modified by paul79, 8:42 PM 5/26/2002]
I have never used headers so will pass this topic on to those who have converted. Sorry I cannot take this further. Many members have and I am sure you will hear from them.
[Modified by paul79, 8:42 PM 5/26/2002]
Racer
Joined: Apr 2002
Posts: 352
Likes: 11
From: Glendale AZ
Re: EFE Emission question (paul79)
I am hearing a "tapping" or "rattling" noise while the car is warming up. It happens after I kick out the choke and the car is idling around 700 rpm.
Ruled out some of the usual suspects, lifters etc. and now think it may be a semi stuck heat riser valve clattering away.
Have you heard of this being a solution to a mystery noise before?
David
Ruled out some of the usual suspects, lifters etc. and now think it may be a semi stuck heat riser valve clattering away.
Have you heard of this being a solution to a mystery noise before?
David
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Team Owner
Joined: Aug 2000
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From: Massillon,Ohio USA
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Re: EFE Emission question (pdgourno)
pdgourno, 1980's have several areas that can cause this rattle. One is what you mentioned being a partially open or loose heat riser valve. On my '80, the front exhaust pipe heat shields below the floor were loose and had to tighten them up with their clamps. Also, my '80's left hot air intake to air cleaner assembly shield on the exhaust manifold came loose and I had to tighten it up also-now, no rattles. :yesnod:
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: EFE Emission question (paul79)
With headers you will not have a flow of hot air on start-up through the intake manifold. The EFE actuator keeps the heart-riser valve shut by vacuum and backs up hot exhaust through the intake manifold cross-over induction system to aid quick warm-up. That is where the heat pipe for the choke sits. When the coolant in the engine reaches a temp of 120F, the thermal vacuum switch (TVS) located in the neck of the thermostat housing shuts down the vacuum to the EFE actuator and the heat riser opens. All of this works in conjunction with the choke and the vacuum-operated heat stoves on the air cleaner horns. Or.......just replace the divorced/heat style choke with an electric one to avoid all of this confusion seen below;) .
This is useful if you need to maintain Emissions legality with headers.
One of the interesting things is you can find emission legal headers however since few install the Hooker EFE adapter (I assume) then technically the car is illegal again..
I do not have a picture of the part but it can be found on page 1130 of the 2001 PAW catalog - part numbers HOO-10929 or HOO 10937 selling for $27.95
[Modified by fauxrs, 11:22 PM 5/28/2002]
Racer
Joined: Apr 2002
Posts: 352
Likes: 11
From: Glendale AZ
Re: EFE Emission question (Paul Borowski)
Paul,
Thanks for the pointers. I will check them out first chance and let you know what I found. I would not be surprised if it is a combination of all three as the sound is not 100% consistent.
Not sure what that shield on the exhaust manifold is shielding me from? It seems I have my choice to burn myself on the shield or on the manifold itself.
:seeya
Thanks for the pointers. I will check them out first chance and let you know what I found. I would not be surprised if it is a combination of all three as the sound is not 100% consistent.
Not sure what that shield on the exhaust manifold is shielding me from? It seems I have my choice to burn myself on the shield or on the manifold itself.
:seeya
Pro
Joined: May 2002
Posts: 726
Likes: 0
From: Petaluma CA
Re: EFE Emission question (fauxrs)
Thanks!! Maybe. 81 goes for smog next week. Will need new actuator. I have been hoping for a solution, as ZIP and others sell act. and riser as a unit for $100...too much! Called PAW this AM and bought them both for $29.
Should be here tomorrow and I hope salesman is right on the part...
Should be here tomorrow and I hope salesman is right on the part...
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: EFE Emission question (Stevo)
PAW has heat risers??? I know about the adapter that i mentioned above but didnt know they had heat risers - would be very interested in what you get from them!
keep us informed
keep us informed
