Im just curious if temperature can cause this because while in park when it was cool the car ran good but now it has gotten warmer and the cough has bern happening more often. Is it possibly because the heat has caused the engine to run a little more rich than usual?

It is possible. Warm air is less dense, which in turn makes for a richer mixture. If your car was on the verge of being TOO rich when it was cool out, then a rise in outside air temp could push it over the edge and cause an overly rich condition (coughing, bogging, black smoke). What color are your plugs?

You may want to check the setting on your choke to make sure it's off at normal temp.

Also the float level could be a bit high, making for a richer mixture, if in fact it's running rich.

Need to switch to (lights):poke:
menthol lights Ha-Ha
Just funnin
Donny

do you have a heat spacer between the intake and carb--sometimes it will boil the gas in the float bowls?/ Just a thought--Glenn:dontknow::dontknow:

do you have a heat spacer between the intake and carb--sometimes it will boil the gas in the float bowls?/ Just a thought--Glenn:dontknow::dontknow:

I have a one inch spacer and i have not checked the plugs yet.i will do that after my car show this weekend

It is possible. Warm air is less dense, which in turn makes for a richer mixture. If your car was on the verge of being TOO rich when it was cool out, then a rise in outside air temp could push it over the edge and cause an overly rich condition (coughing, bogging, black smoke). What color are your plugs?


PRECISELY
:dontknow:





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ok i let the car warm up and i gave it a few hard revs in park and on the fourth rev there was a bang from the carb. I think its a backfire? Is that usually caused by being too rich?

You may also be getting a cross bleed from your plug wires. Wires running right next to one another will often bleed to the wire next to it. Change there routing a bit.
That's what it sounds like to me. Also a good set of 8.5 or 8.0 wires will help in that case. (GOOD ONES LIKE MSD or the like, not the cheap 40 /50 $ ones.) Common with HEI Distributors and MSD Type Ign. systems.

You may also be getting a cross bleed from your plug wires. Wires running right next to one another will often bleed to the wire next to it. Change there routing a bit.
That's what it sounds like to me. Also a good set of 8.5 or 8.0 wires will help in that case. (GOOD ONES LIKE MSD or the like, not the cheap 40 /50 $ ones.) Common with HEI Distributors and MSD Type Ign. systems.

i dont have HEI though

Still possible, How are your wires anyway? Just a thought that gets overlooked far too often. If you are able $$ wise, you might just give it a shot. Would definitely not hurt.

Still possible, How are your wires anyway? Just a thought that gets overlooked far too often. If you are able $$ wise, you might just give it a shot. Would definitely not hurt.

boots are cracked but i did the trick where u look at the wires while the car is running in the dark and there is no glow

If the BOOTS are cracked, then replace them even if you have to buy the less expensive ones.
Those wires you have must really be quite old for the Boots to be bad, Wires most often go bad long BEFORE the Boots do.
And while your at it, Do the Cap and Rotor as well.

If the BOOTS are cracked, then replace them even if you have to buy the less expensive ones.
Those wires you have must really be quite old for the Boots to be bad, Wires most often go bad long BEFORE the Boots do.
And while your at it, Do the Cap and Rotor as well.

I was planning on saving for msd wires a mallory cap and new spark plugs

If your not running HEI and have points and condensor, it wouldn't hurt to replace those along with the cap and rotor. Cheap money for peace of mind.

yea and unless ur trying to keep a matching numbers original swap the cap to hei... well worth the hotter spark and the save on gas $$$, plus u will get more hp

yea and unless ur trying to keep a matching numbers original swap the cap to hei... well worth the hotter spark and the save on gas $$$, plus u will get more hp

I dont have that kind of money though:???:

Just chacked the plugs and they look good:dontknow:

If the plugs look good then your mixture is probably close enough to not be the problem. I would DEFINITELY start with replacing those plug wires. Cracked boots can cause all kinds of misses, coughs, and backfires. I'm assuming your timing is set correctly and your vacuum advance is working correctly.

The plug wires for #5 and #7 need to cross over each other (not running parallel and pretty). they fire with in 45 deg of each other and will cause a mild cross fire through induction if parallel. That is why the factory had them crossed.

I'm thinking you still have carb issues. Did you ever get that Holley tuned in? You may have other issues as well. But you had several posts about your carb. Oh, save your money and upgrade that old points distributor. You'll be money ahead in the long run. I'll sell you a good used one for $50.00 plus shipping.

A backfire through the intake (carb) has always been a too lean a mixture from my experience. That's aside from the ignition though. A point type distributor will always be a maintenance item. The GM HEI was the best thing that ever happened to GM cars for ignition. They must be good, because all the after-market folks copied them:smileyb:

The plug wires for #5 and #7 need to cross over each other (not running parallel and pretty). they fire with in 45 deg of each other and will cause a mild cross fire through induction if parallel. That is why the factory had them crossed.

well that doesnt make sense. and also can they cros at any point like lets say right as they come off the distributor?

Make them cross in the area of the rear of the Drivers Side Valve Cover. Remember, 5 fires, then 7 fires, and they are BOTH right next to each other. ↓↓ -- Study the photo, and it will start to make sense to you.

http://i300.photobucket.com/albums/nn18/coyoteon2/miss/350_firing_order.gif

PLUG WIRE ROUTING


Okay. I will describe it. On the left bank, wire #3 crosses over #1 about intake manifold level. On the right bank, wire #8 crosses over #6 and #4 at about valve cover level.

#5 and #7 should cross somewhere down toward the plug end. they are the ones next to each other in the firing order (1 8 4 3 6 5 7 2). 7 is charged with fuel and 45 degrees away from firing when 5 fires. This will be a back fire though the carb as the intake valve is just closing. When 7 fires it can induce a spark in 5 during the exhaust stroke and if you are running a little rich you get a back fire in the exhaust. If the wires are parallel for a little ways they can induce a voltage in the other wire.

Cross the ones we are writing about, When they run alongside each other the wires we are referring to can cause the cross firing.


http://i300.photobucket.com/albums/nn18/coyoteon2/miss/distributor-1.jpg



NOTE: Just trying to HELP YOU make sense of how it happens.
But remember this, "What do I know"

If the plugs look good then your mixture is probably close enough to not be the problem. I would DEFINITELY start with replacing those plug wires. Cracked boots can cause all kinds of misses, coughs, and backfires. I'm assuming your timing is set correctly and your vacuum advance is working correctly.

yes i had that done when i took my car to my mechanic for a wheel alignment. its set to ten degrees advance and is running well. i am reallying leaning to those wires being my problem