Lets Play, what is this!

[RandyP]

Ok, what is this in the photo that is circled? I'm really wanting to remove it.

78 K5 4x4 400 with 350 auto and 203 transfer case. I'm about to go to town removing vacuum lines and putting plugs in. I know (if it had any) the emissions were removed long ago, no AC and the cruise really has no function other than connecting the speedometer cables together (for now), no cruise switch on the column in it now.

I'm putting new plugs in it and this little jewel and me are about to around and around.

[PRattenbury]

Youmay be better off going to the junkyard or flea bay and finding a carb and intake from 1973 and older that doesn't have all the EGR crap and other emissions related junk on it. Rebuild the carb for 50 bucks or so with a kit. Then you'll have vacuum for power brakes, PCV valve, and distributor diaphragm. Oh, the transmission modulator valve, too! All done.

[RandyP]

I have $400 in the truck, and maybe another $200 in misc items (plugs, wires, battery) and then $100 for a used column. I am not wanting to sink any more bucks in it than I have to, I can deal with plugs.

I just don't want to go and remove something that is some sort of sensor or the likes that makes it run good.

I am absolutely amazed at well this thing runs after putting seafoam in the intake, using B12 to clean the carb and putting new plugs in it (and two wires that fell apart). I have never had to use a 2' cheater bar to get a plug out before, guess they didn't believe in putting any antisieze on them the last time it was done.

[PRattenbury]

Okay, just sayin...

[Kurt L]

is there an engine under all that ??????????? lol

[RandyP]

OK then, so it can't be anything that important. The vacuum line goes to the water neck, and the Y in the line it is on, the other line went up to the air cleaner housing.

And yes, that is a crap load of vacuum lines under there, especially for a 79 model. It's about to go on a diet under the hood there tomorrow. I'll stop off at Advanced and get a kit of plugs and start going to town. I know I need the EGR, and will probably keep anything that goes to something that hooks on to the carb, in case it is part of the choke or something.

I also need to follow the two big hoses that run off the cruise module and see where they go, maybe get rid of the cruise module and put a 1 piece speedo cable on it.

[78 Chevyrado]

The thing circled in the picture closes the valve in the exhaust to block it off so exhaust will flow through the crossover in the intake manifold. This helps the engine warm up quicker. If you remove it, make REAL sure the valve in the exhaust is permanently blocked OPEN. If you dont youll end up with that side exhaust manifold glowing red one day.

[RandyP]

Finally found the item in question in the Haynes manual. They are calling it a Power Actuator (Early Fuel Evaporation system?), and should have a rod going down to the exhaust to open and close the valve (as you mentioned, 2 points!). Only issue is, there is no rod going anywhere off of this thing. Now I'll have to go back and see if any of the pieces are on the exhaust or not. It has had duals put on it at some point, so I'm doubtful it is still there.

[Brian76GMC]

Thanks! Now I can take that crap off of my '79!!!!!!!! ahahahaha

[RandyP]

That power actuator does have an arm going down and is hooked to a door or something. It does move and I can feel a spring with tension on it. For now I'm just leaving it be I guess, since I don't know which way is open. I do see a lot of steam coming up out of the right manifold, sorta makes me wonder if the door is really moving inside the pipe.

[dswancutt]

It controls the heat riser on the exhaust manifold, part of the light duty emissions package for that year. I have a 78 k10 with the heavy duty emissions and it doesn't have any emissions gear. Your best bet is to find a 78 big 10/heavy half with heavy duty emissions.

[rayfinseats]

Who's the genius who invented all that crap anyway?

[motornut]

some of the heatrisers have a little nib stickingout from the valve that can be tied off to keep open
some can be removed, it can be easier to remove the valve and tac up the holes left from the valve

[motornut]

this is what it is made like basicly
some just get a spacer to replace it last pic
but i've also seen a whole drilled in the pipe wire poked in an used to prop it open and tac the busted off nib /valve open

[RandyP]

I have yet to crawl under the blazer and look at what it is on the exhaust. If it is indeed a piece like you show, that is removable, it just might find itself removed and made hollow and put back.

I'm also going to just make a plate and cover the EGR area on the intake, or so I think. I'm serious about doing this as low budget as possible, I really don't want to end up with over $1000 in this old beater.

[motornut]

Originally Posted by RandyP

I have yet to crawl under the blazer and look at what it is on the exhaust. If it is indeed a piece like you show, that is removable, it just might find itself removed and made hollow and put back.

I'm also going to just make a plate and cover the EGR area on the intake, or so I think. I'm serious about doing this as low budget as possible, I really don't want to end up with over $1000 in this old beater.

i used a piece of thick steel cut to shape and removed the plug stickin out to cover it,but put the piece back
that worked for a little while (found it burnt threw the next year) got the right cover

[cr34t3d_by_d4rkd3n]

Originally Posted by motornut

this is what it is made like basicly
some just get a spacer to replace it last pic
but i've also seen a whole drilled in the pipe wire poked in an used to prop it open and tac the busted off nib /valve open

Just take a torch to the butterfly valve its self and remove it, keep its appearance for smog even tho its empty.