Pics of my new "project"

[zachmac]

In the Factory Service Manual for the 80 FI they refer to part your talking about as a "throttle plate heater".[/quote]

And clearly that is what it does. The question is why? I haven't found a source that explains its function but again I am making an educated guess that it is to help meet emissions. It is commonly understood that cars put out more unburnt fule (pollution) before the get to full operating temperature. I think this is just an attempt to hlep pre-heat the air charge via coolant circulation and conductive heat transfer to help get to the lower emmisions point faster. Once the car is warmed up it shouldn't serve any purpose and in fact is detrimenta; to making power since it is now needlessly heating the air going into the injection plenum. After all, why do we bother with cold air intakes if warmer air is better (we like power versus totally clean burn).

IF you can live with adding to your carbon footprint, remove it and just connect the hard pipe point to the heater core return line T.

BTW, I haven't fully thought this out but it could be that once the negine is warmed up having it there or not is moot as the heat coming up from the block at that point exceeds the coolant heat transfer from this part. I would still think however that not having that hot water blanket in place would help dissipate that heat and keep in inlet air charge cooler.

[kristoj]

The throttl plate heater design changed between 1980 and 1981. In 1980, it was an complete bolt-on part. In 1981, they redesigned the plenum with the bottom half of the throttle plate heater molded in and the top half held on with four nuts. You cannot buy a new gasket (at least I have never found one) and I would not recommend using a liquid sealant as it can ooze out and block the small passageway. I bought a sheet of gasket material (designed for waterpumps) at Autozone and cut out my own gasket. It has never leaked since.

[Foster48x]

I was also thinking about bypassing mine due to leaks but didnt after reading that the "Throttle Plate Heater" heats the... well... Throttle Plate (go figure) to keep the throttle from sticking during extremely cold weather. I live in Texas, we only get a few really cold days each year but I decided to keep it anyway.

Rick

[cutchaguy]

Good news. Took the old plugs out and they look like they have been working well. Bad news. One new one won't go in as easily as the other three. There was a TON of dirt around the base of the plugs that it took an hour with bamboo skewers and my shop vac to clean it out first. I can't imagine how so much dirt got so compacted there. It made me wonder how long they've been in there.

[manoa matt]

Given the "valley" design of the head its always good practice to use compressed air to blow out all debris around the plugs before removing them. A tiny speck of sand could really screw things up inside the cylinder.

[cutchaguy]

I had a small can of dustoff but I think I about to invest in an air compressor, aren't I.

[htchevyii]

On some early f.I. cars the heater is seperate. On the later cars it seals to the t.b. With a gasket. It preheats the intake in cold weather. My engine gasket set came with a cork gasket that leaked, so I used silicone instead. You could bypass it by hooking the hoses togeather or capping the nipples.
Gee, I just realized I didn't change the page and your questions have been answered.

[ga.spyder]

Got in a little late.Congrats on the find.It looks just like my project car!Even the top.Yours has one thing mine doesnt,though.Fuel Injection!!!
Craig

[adrians]

I managed to purchase a new "throttle plate heater", bolt on type not the free standing unit. It didn't come with any gaskets, I just used normal gasket sealer, as you would with any other part that has hot water passing through it.

PS: clean all the parts well, there is lots of build up on the them.

[narfire]

Yea..throttle heater,supposedly people used to drive these cars when conditions could create "icing" on the inside of the plenum. Mine is one piece and comes off easily,need another,try the "parts for sale" section here,several are parting out FI cars.

[cutchaguy]

Matt...I sent a PM.

[CalJim]

The throttle plate heater is piece of safety equipment for folks who drive in cold damp climates. The pressure drop across the throttle plate can cause moisture in the air to condense and freeze on the throttle making it stick, and maybe stick open! I live in southern California where I'm not worried about this and I removed the leaking one from my 2000. If you take trips to the mountains in the winter you might want the throttle plate can be heated.

See http://en.wikipedia.org/wiki/Carburetor_icing