tuning

[Lee H]

I bought a 79 recently. L82 motor with edlebrock air filter, manifolds, headers. The motor looks real clean like it was well cared for. I think most of the emissions related stuff has been removed. No catalytic converter. I don't know if i'm in for a problem when I register it in New Jersey.
Anyway, It ran great in Sept. and has sat for a while while I worked on my windows and interior. Last time out though it ran rough, backfireing and missing. Maybe cold weather related?

Does removing all the emission equip. make it more difficult to tune? I noticed 2 vacuum port on the carb that have been plugged. Can I still expect to fine tune it so it runs smoothly.

 

[Roy]

Don't Worry

Removing the smog control devices does not preclude you from tuning the engine for smooth running and maximum performance. It will just take you a while to experiment with what helps/hurts your engine performance - a perfect winter project!

Start with the basics and make sure what you have works correctly. Start with a compression check. If you have good compression, the rest is simply a process of elimination.

Tell us what you have and you will get a ton of ideas to follow-up on.

The two ports on your carb being plugged should not cause you any stress or concern. You can hook up the distributor advance hose now or later. With all the smog equipment off the engine, you might want to make sure that all remaining vacuum ports and hoses are sealed.

What kind of carb do you have? How long since a rebuild? Type of choke? Operating? Adjusted correctly?

 

[Lee H]

carb tuning

Rochester Q'jet carb.
#17054939
#35002 written with pen on choke flaps(don't know if thats significant)

I just finished reading my Haynes manual on adjusting. Must be my ADHD but found it difficult to understand.
Is there any manuals on the subject that may be more simple to understand. The carb appears clean. saw some new teflon tape on threads so I am lead to believe that it's been maintained if not rebuilt. This is a 1979 car.

 

[tazdevl35]

Take a squirt bottle filled with water and spray the plug wires and dist cap while the engine is running and see if it runs rougher..if it does you need at least a set of wires. Also remove the dist cap and look underneath the inside of it for moisture or signs of arcing/burnt terminals etc. Let us know what you find.If thats not where the problem lies the we'll go a bit deeper



Taz

 

[gooney0]

Vacuum leaks (hoses) and gaskets (intake , carb) can cause problems too.

To test the carb and intake gaskets:

start the engine
spray carb. cleaner around the base of the carb, and around the edges of the intake. This should have no effect on the idle. If it does you have a leak where you sprayed.

You could also check all the other "cheap" parts like the fuel filter, PCV, etc. etc.

-Gööney0