NathanC5

ok, my engine combo is listed in my sig. Anyway, the car starts right when its cranked. The choke is working properly as it idles high and kicks down with the peddle. The problem is that once it gets to its normal idle its rough. Once you drive it around the car is fine with no idle problems. I then stop, go to class and when i come out its the same thing. the idle is rough and surging, but as soon as i drive away it clears up.

five7kid

iTrader: (14)

No sig.

Sounds like improperly adjusted idle mixture, vacuum leak(s), or bad valves.

NathanC5

could it be ignition related? this problem occured after having a spark plug wire touching the manifold for quite some time. the wire was taken off the manifold and the idle has been weird since. I have replaced that wire and the problem persists. its an old wire though that replaced the burned one. not a new one.

kboehringer

NathanC5,

RE: could it be ignition related?
Unlikley....but a slim possibility.
If the plug wire in question was replaced.... Did you take the time to look at the plug and clean or replace it? If it spend a bit of time not firing because of the bad wire it's could be fouled. If you have any question about that particular wire you could hook your timing lamp to it (DO NOT TIME TO THAT PLUG UNLESS IT'S #1!!!) just check to see if the lamp flashes. That will tell you if the plug wire is carrying any juice. But make sure you pull and clean the plug. For about $1 each you can get a whole new set from AutoZone for less than $10. You can never go wrong with a new set of plugs.

However, I agree with Five7 that is most likely a carb problem. The proper set-up for a Rochester seems complicated but it's not in reality. Before somebody chimes in and tells you to toss the Rochester in the trash (there are a few people around here that feel that way) take $15 and drive over to your local AutoZone or Advance Auto and get a Haynes Rochester Book (see photo). It's the best $15 you'll ever spend if you have a CCC-Carbed ThridGen. The Rochester is [IMPO] the BEST carb for a stock or mildly modified SBC. It's the ONLY carb for anyone with Emissions Requirements.

I recently had the SAME problem with my Son's Q-Jet and it turned out to be a bad O-Ring on the Idle Air Bleed Valve. The O-Ring had broken up and little pieces had found their way into the Idle passages within the carb. It was a minor little problem that took me some time to figure out (Thanks Damon & Lo-Tec!)

Hope that helps.

Sincerely,
Kurt

NathanC5

ok, i will check the plug, but the carb is new.

kboehringer

NathanC5,
The NEW carb needs to be checked when it is/was installed. I would hope that a NEW carb would be very close to proper adjustment but it is unlikely you would get lucky enough to find it is 100% directly out of the box.

However, since it is a NEW carb I would double check every vacuum line attached to it and determine if you have a leak on the OUTSIDE of the Carb before you perform any carb disassembly.

Sincerely,
Kurt

NathanC5

well the car was running perfectly when we put this carb on. a little while after my torque converter went south and had to be replaced. none of the wires were touching the manifold before this, but after i got it back it ran weird, and i was assuming the converter was at fault. turns out that when they replaced the throttle cable they must've accidentally made this spark plug wire touch the manifold. what happens to a plug if the wire isnt sending the correct spark anyway? does it get fouled?

kboehringer

Nathan,
The intake valve(s) are still opening and closing and the fuel air mixture is still being "Pulled" into the cylinder on the Intake Stroke. If there is no spark to ignite the mixture on the Compression Stroke the plug(s) can get pretty screwed up/dirty.
One bad plug can make a car run like POOOOO.

If the guys that replaced the Torque Converter "MOVED" your plug wires for some strange reason......chances are they "MOVED" some of your Vacuum Lines. There are a couple lines on the back part of the engine (Brake Booster, A/C Vent Source, MAP Sensor) that might have been "MOVED"

Please do yourself a favor and check ALL the vacuum lines!! Don't get tunnel vision on this plug without checking EVERYTHING!


Kurt

NathanC5

ok, but i dont have the slightest clue on how to check for vacuum leaks

NathanC5

it was a timing issue. my timing was far too advanced. the plugs were fine and no vacuum leaks. thanks for all that chimed in.