idle problem
 

Hey guys, haveing an idle problem seems like a vaccume leak.i have checked almost everything, its a 302 cobra with a holly 4brl edelbrock intake. it surges at idle and the vaccume gauge move drastically inbetween 8 and 15, i had to incress the idle screw just to get it to not stall. any ideas?

Re: idle problem
 

I am assuming you have not worked on anyhitng recently and this is a new problem? Have you tried to spray carb cleaner on all the normal spots to see if you can hear a change in the idle?
Ryan

Re: idle problem
 

no i havent worked on anything, but when this started happening the car was dieing badly low rpms no vaccume i thought coil wire was bad so i changed the wires, still did it. finaly i figured out that the carb was getting flooded and the float mite be stuck. it was. fixed that now i still have the idle problem. i havent tryed the carb cleaner but i will get some today. also i replaced the hose for the vaccume advance thought maybe it was that.

Re: idle problem
 

Try adjusting the idle mixture at all? Might just be running lean now.

Re: idle problem
 

ok guys tryed the carb cleaner, no good. tryed adjusting the mixture, same results. what is the possiblity that i have a bad plug? is their any?

Re: idle problem
 

Are your plug wires on the right plugs? I make that mistake occasionally and the engine won't idle worth a damn on 6 or 7 cylinders, LOL. Go through the firing order and check that. You did say you havn't changed anything recently, so it's not a likely solution. Just trying to cover all the bases. You can pull the plugs and check that they all look OK. A non firing plug will look all wet and a proper firing one will be dry and tan or grey, but I can't see any reason that it would occur out of the blue. Not much help here but I'm trying to think of things.

Rev

Re: idle problem
 

do a compression ck on all 8 cylinders

Re: idle problem
 

ok i thought i had this problem fixed. i was wrong. car still dies at idle it will idle for a min and then starts to run ruff and dies it does it in drive neutral and park. heres what i have done. i have changed the plugs, wires, condenser, points, tryed to adjust the mixture on the carb checked for vacuume leaks. i think i have thought of everything. all the wires are correct. still haveing this problem and advice would me helpfull
thanks
matt

Re: idle problem
 

Are you really running a dominator on it? How did you get it on a performer intake?
Check your fuel filter and fuel levels.

Re: idle problem
 

checked the fuel filter. everything is clear. fuel levels are good. floats are set right below the siteglass as i believe they should be. not running a dominator anymore. when we rebuilt the motor we changed some things. the motor builder put the dominator on it somehow. but since that has been changed. bout a yr now. it has a holley 600cfm street carb on it now. another question i still have the Autolite 4100 that came with the 289 thinking about haveing it rebuilt and using it.
but if you can give me any other info i would be thankful
matt

Re: idle problem
 

Have you checked the fuel level after it dies? Pull a plug and see what it looks like.. it also might be flooding if there is some dirt stuck in the needle valve. Look inside the carb bores and see if there is fuel dripping when it's running.

Re: idle problem
 

i did notice something. when the car stalled and i turned it off, i could hear fuel dripping. i thought maybe the float was stuck so i took the bowl off everything seemed fine when i looked at it. i was thinking that it was flooding. also when i go to start it it takes a min or two to turn over. i have the carb pulled now and have been trying to figure out whats wrong. i think i mite have narowed it down to the carb. just didnt know if it would cause the non starting. i can see it flooding when it idles thats why it smokes so much when it starts back up. the carb is less than a year old. if something is wrong with it should be this eairly that its messing up?
thanks
matt

Re: idle problem
 

Sounds like dirt in the needle valve. Pull them out and make sure something isnt caught in it. Yes, that would make it hard to start because it's flooded. Make sure the rubber tip doesnt have a groove or something. Sounds like you found the prob. :D

Re: idle problem
 

ok i will try that see if that does it. thank you for all your help. i will post me results. i can tell you this board has helped me more than any shop or parts house. im glad to be a member
matt

Re: idle problem
 

No prob, that should fix it. Only other thing would be fuel pressure.. what pump are you running?

Re: idle problem
 

If the needle and seat are leaking, it doesn't cost much to just replace it with a new one ($10 or so from O'Reillys). Usually when the needle and seat are bad, you can see gas dripping into the throttle bores (primary or secondary) when the engine is idling, making a very rich (black smoke) condition. When this occurs, there's a very high float level due to the float not being able to shut off the gas inflow into the bowl. I've had this happen several times, but it was easy to see what was wrong.

Rev

Re: idle problem
 

I had a similar problem recently and it turned out to be some dirt in the carb - it does not take much. I cleaned it out and used one of those cans of compressed air we use on computer keyboards to blow around the needle valve area. Works great. E.

Re: idle problem
 

thanks for the posts guys. i havent had a chance to try anything yet. because turns out i stripped the threads on the card and waitting on a heli-coil kit from holley. should be in tomarrow. thanks
matt

Re: idle problem
 

What did you strip out?

Re: idle problem
 

Just guessing of course, but the ones I always strip out and have to repair are the cap screws that hold the float bowls on.

Rev