Sorry, I'm a newbie here. I have an '86 V8 LG4. Do I have an manual or electric choke?

If I buy a new carb, which should I get? Which is "better"?

Also, what is EGR?

Thanks!
John

 

It came with an electric choke. If it's still as-delivered from the factory, it's electric.

What carb is "best" depends upon what you're doing with the car. Assuming you mostly drive it (vs. only racing it), then you already have the best carb on it. It can be improved - see the tech article - but it's hard to beat for a driver.

EGR stands for Exhaust Gas Recirculation. It's an emissions-reducing device. Unless you are willing to go through some extensive customization, it's best to leave it there and have it working.

So you'll know I know a little of what I speak, I'll include my sig.

 

Thanks! That's exactly what I wanted to know...I'll leave my carb as is, but if I ever need a new one, I should get an EGR version with an electric choke.

Could you briefly explain how the EGR works? For example, I notice a small metal pipe going from my exhaust manifold up into my air cleaner, is that the EGR? It's hard to imagine that would make any difference to the carb. That pipe had disconnected from my air cleaner at some point and I never noticed any difference.

And how does EGR affect the carb? Edelbrock seems to offer EGR and non-EGR carbs, how are the carbs different?

John

 

the round thing under the spark plug wires is the EGR. can you copy paste the what edelbrock said about the EGR. im not sure you read it right, but i, like always, can be wrong.

BTW: the only time i heard that the EGR comes from the manifolds to the air cleaner is the corvette, however, i still dont believe that it goes to the air cleaner, but rather a vaccum port.

 

o ya, and sorry about the massively dirty engine, that has been taken car of.

 

Your carb is computer controlled. Edelbrock doesn't make one like it. Nobody made carbs like it except GM (although there are reports that Holley made some CC models for the blue oval).

What Edelbrock is referring to is pre-computer emissions-type carbs. Doesn't really apply to you.

EGR is intended to reduce nitrogen oxide compounds, produced in conditions of high pressure, high temperature, and excess-air. Those are all present in some cruise and light-load running. So, they reduce one of the components, high temperature, by diluting the incoming air/fuel mixture with a little bit of exhaust. It has the desired effect.

With non-computer carbs, a vacuum port is used that doesn't apply vacuum all the time ("timed", or ported vacuum it's often called). For computer controlled carb/ignitions like ours, the computer decides when to open the EGR valve, and sends a signal to a solenoid to do it.

The pipe you are referring to is actually a warm-air system to help the engine run a little better when it's cold. It doesn't actually draw exhaust up through it, just air that's been warmed up by going around the outside of the exhaust manifold.

EGR is internal to the intake manifold on our cars (some Vettes have a tube from the exhaust manifold to the intake manifold for the EGR, but not on carb systems).

 

And have you taken care of the "sensor" in the manifold behind the carb????

 

ya we did, new manifold (along with a new engine and clean engine bay)