Once I figured out my cold start problem (running outta gas, gauge is off) I begin to adjust the carb and suddenly my motor starts running rough and in order to keep it running I turn up the idle speed. So now it continues idleing (like crap) while I try adjusting the A/F screw, but suddenly smoke begins to come from the engine and I immediatly turn off the car. I looked under the car to see that the center of the 1st catalyzer is glowing red and the rubber exhaust mounts were smoldering. I let it sit for a few minuets and try again same thing, only this time I noticed that the motor still runs (like crap) and even with the Air/Fuel screw all the way in it still ran. The car was running fine until I started adjusting the A/F screw. The previous owner told me that the cats were hollowed, I have no clue whats going on. After I get this problem figured out I'm never touching that carb again!

 

Check your timing

 

I'll check my timing, also it may be a vacum issue because my engine started surging a bit. If any thing else pops up I'm gonna sell the damn thing for an FC or go back to a camaro, I miss fuel injection!

 

sounds like you are getting trailing only. That is usually the symptom. Check your ignitors and pull your spark plugs.

 

checked the ignition, every thing's fine, I think it may be a vacume leak because the engine surging and could possibly explain the why it could still run with the A/F screw all the way in. I don't know whats up with the cat glowing it only happens when I lower the idle. The neighbors have began to complain about the smell and the smokey start up so I'm going to have to wait for the wind to pick up before I work on it some more. I'm thinking of just replacing all of my vacume lines.

 

You checked ignition, everything fine? meaning you do have leading ignition, and it's not retarded?

 

didn't check the timming yet, I just made sure that all plugs were firing consistantly. Does this sound like a symptom of timing retard?

 

Yeap. Did you put your hand on the dizzy for support while adjusting the idle mix screw and accidentally rotate it towards the firewall? that's what it looks like.

However the fact that you were ******* with the idle mix screw would point to that area. It blows me away that you are adjusting the mix screw, the car starts to idle roughly, and to handle it you adjust the idle screw! anyways, re-adjust the mix screw to its original setting, and then the idle screw. Idle should be 750 rpm.

There is of course always the possibility that while messing with those screws you moved a brittle vacuum hose and developed a leak.

 

Let's see, vacuum leak raises idle and leans out the afrs due to the introduction of unmetered air, so you turn the airmix screw in and lean the mix out further. I have no idea why you would be glowing, lol. Check your timing too.

 

I figured the air screw didn't kill the motor because I had the idle cranked up as high as it would go to keep the sputtering motor going, once i turned the idle down to 750 (@ 1400 before) the A/F screw functioned as it should. The engine runs like trash through the entire RPM range so I think your all dead on with the timing. I'm going to check my timing as soon as my broke self can scrounge up the cash for a light, or hopefully a light rental. Thanks again for all the help, if all I had was my crappy hayes manual that car would be sitting in my garage for a very long time.

 

You can use the ghetto method on your timing if you are daring. Rotate the dizzy clockwise just a tiny bit (picture 3 minutes on the face of a clock). Then take it for a hard drive. If you hear a sound like marbles being shaken inside a tin can, then you have gone too far and are hearing pinging from detonation. If this happens, then just rotate the dizzy a little bit counter clockwise. Use this to find the maximum advance you can run without detonation...

 

I just picked up a sears inductive timing light off ebay for a total of $15, once I check the timing I'll post the results

 

And it's not an air screw you n00b , that is a fuel jet. Screw it in, less fuel, screw it out more fuel. Get it?

You're probably right about raising the idle being the reason for the mix screw not doing anything. That screw only controls the idle circuit, so after about 2k rpm, it does nothing.

So post your timing and let's see if that's what the problem is.

 

i would bet its way too lean. being too lean will cause detonation and eng temps to rise. The carb is screwed...easier to change to webber

OR check for clogged fuel filter, bad fuel pump, crimped line, clogged jets inside carb, sticky float,

 

I fixed it, I thought about what blazer1313 said about fuel starvation, so I mearly sprayed some choke and carb cleaner down the carb and now the motor runs great and nothing is glowing or smoking. I honestly didn't think it would work, but i gave it a shot and lucked out. Hopefully the engine will stay this way.

 

i hate the nikki carb........this is why I got a SE