terrible idle at cold start up

[1979C20]

So winter rolled around and its finally getting cold. In the morning when I start up my truck, the right side of my exhaust dumps black smoke and the truck runs like its missfiring terribly. Its a 79 c20 with a 350 stock rochester qjet, headers, and true duals glasspacks. I have to rev up the engine to about 3k and hold it for like 15 seconds and it clears out and idles normal. What would cause this?

[Irish_Alley]

a choke maybe. how cold is it and what do you have as far as emissions

[1979C20]

The choke works properly, after I get the engine to clear out, the choke keeps the idle at about 1100rpm and then when its warm, I crack the throttle and the idle drops back down to the normal 550rpm. All I have emissions wise now is the EGR. Removed emissions exhaust manifold, CAT converter, and AIR pump. Ive got headers and glasspacks now.

[Irish_Alley]

i think not sure but i think a dirty egr can due that till it gets hot enough

[1979C20]

That sucks! Looks like its time to buy myself a EGR block off plate and just run no emissions. I forgot to mention, I pulled my vac canisters out too.

[Irish_Alley]

Your idle is at 550? How you do that mine is at 900 it seams to run good there. I know if my choke is on at first its ok then it will load up and smoke and act like its missing till I give it gas to open the choke even with the choke on its only about 1100

[Irish_Alley]

just look at what other people said and 550 is about norm in park but even when I had my engine in my 86 with a th350 it would seam to only like to run 900 or higher in park so it wouldn’t stall in gear makes me wonder what I got in my engine lol

[1979C20]

Ive got a really large cam in it, so I can set the idle lower. Its got a nice grumbly rhythm to it. Runs fine. I ran it at about 7 or 8 for a while, but it seemed really high and I was burning a lot of fuel. But it runs smooth at 550. My truck is a manual also.

[necromonger]

throw egr in trash.buy cover plate seal it good drive and be happy.

[1979C20]

where can I buy the cover plate, how much is it, and can I buy it locally or would it be from like summit or something? And, would unhooking the vacuum line from it work in the mean time?

[Irish_Alley]

http://www.summitracing.com/search/Make/CHEVROLET/Engine-Size/5-7L-350/Engine-Family/Chevy-small-block-Gen-I/Year/1984/?keyword=egr+block+off+plate
But like we said before don't just buy parts and put them on. It probably wont fix it

[1979C20]

What do you mean, irish?

[screamin86]

I've always made the plates! I've got a couple of them I had on stock qjet manifolds laying around.I've got one on a cast intake and one on a aluminum factory intake.

[1979C20]

how do you make them? Pull the egr off, trace it on some sheet metal, cut it out and silicone it on?

[Grim 82]

Pull the egr off, trace it on some sheet metal, cut it out and silicone it on?

Yes. Drill it before you cut it though.