I've developed an idle issue I can't seem to fix. I've taken the carb apart/cleaned and re-***embled it about three times now and no go. At idle there is gas "spurting" out of the tube that is connected directly to the bowl (main nozzle). When the car was idling nicely, there was no gas coming from the tube. In the diagram link below it is called the main nozzle. I tried blowing air through the "Idle air bleed" port (page 6 of the diagram). That seemed to clear out the problem until the car sat overnight. After three attempts at cleaning out the p***ages and rebuilding the carb. I'm ready to ask for help. It seems to me that something is causing the gas to pull through into the main channel before the rpms come up enough to here it should do it. That makes me think something is causing too much vacuum in the venturi - but what would cause that? So far I have: Rebuilt the carb Pulled the vacuum line for the dizzy and plugged the carb Checked all gaskets for leaks Installed a pressure regulator set at 2psi http://www.oldcarmanualproject.com/...3/MCarbHollIHC53E322B/MCarbHoll_IHC_53B5.html Engine idling before the issue: http://www.youtube.com/watch?v=fa45-zZRmRc
Take it apart again use spray carb cleaner and GOGGLES. spray through every orfice and see where it comes out. Sure sounds like something is stopped up. that carb is too simple to have much wrong with it .
I have taken it COMPLETELY apart several times - let the bodies soak overnight in carb cleaner tub - blown out EVERYTHING with carb cleaner and air pressure. Something is causing the main circut to kick in at idle. If you pull the choke or hold the throttle at 2k rpm or above it runs fine. At idle the main nozzle (the tube that runs into the body of the main well) is dripping/spurting gas and flooding it. I ***ume that to be too much vacuum - but what causes that? I have disconeected and plugged every vacuum port on the carb and still have the same issue. Something in or beyong the intake manifold is causing too much vacuum I think.......????
Try soaking it in the "purple cleaner" for an hour or so, wash out with hot water and blow dry thoroughly. If the cleaner appears to be eating on the metal dump it quick and wash with water. The cleaner will eat on inorganic matter that may be plugging the p***ages (mineral scale as opposed to varnish).
Sounds like something goofy with the metering circuit, but I'm no master at carburation. I remember awhile back somebody discovered that the needle and seat in some of the foreign made rebuild kits would not seal causing the 1904's to flood. I think the seat opening was too big. Would this cause a problem at idle? That's a stumper, post the solution when you get it. Did you put in an electric fuel pump? They are sensitive to high fuel pressure too. They like something around 3-4 psi.
I actually have kept the original needle/seat as it looked like a better set-up with spring etc. It seems to be working fine. New fuel pump is mechanical - but rated at 5-7 psi. I added a pressure regulator because I read that the 1904 only needs 1.5 to function.
Double check to make sure that the float is okay. It could be fuel saturated, ie too heavy. Make sure that the check ball in the accelerator p***age is there or is the right size. Just my thoughts. Matt
Float is good - I have been able to adjust it and alter the fuel level. Check ball in place and rolling. Same ball was there when it idled fine. Because I was able to blow air into the idle air byp*** and stop the problem once early on- I am more convinced it must be the power enrichment dizzle. Now, hot to fix that thing???
If you have allready tried another carb that you know was working fine, and you still have the same problem, then how do you figure its the carb? These carbs have a port on the bottom side for vacuum, did you happen to block this off because of the wrong gasket, etc...??
ditch the 1904 and get an 847... there were SO many different versions of the 1904 that finding the CORRECT parts for one is a pain... a base from one might not work well with the top from another... gaskets wont line up right from one series to another etc...
I've been asking what else would cause excessive vacuum in the manifold - that is what I think is causing the problem. I'll check the vacuum port on bottom - that's a new one to me. Thanks!
Looked at the hole on the base - it opens directly into the throat body - no hole in the gasket or the manifold for it.......
Problem is solved! Big thanks to Mr. Rio Rancho! I soaked the metering mechanism in purple degreaser for an hour - washed and dried it out - re-***embled and wha la - she's back in shape! I guess that can of "carb parts cleaner" belongs in the trash - i soaked stuff in it overnight and it didn't clear out the p***ages like on hour in the purple degreaser did! I am impressed and in awe! THANK YOU SO MUCH!!!
hello! i have a 1954 ford f-350 with a 223. 1904 holley carb. i am rebuilding it and i have a piece left over. its a little cup shaped piece. i can see that on the "dome side" it has what looks like a wear pattern like it was rubbing, or hitting something else. it kind of just fell out when i took the main well/econ body ***embly off (number 30 on the diagram) i can seem to find it anywhere on the diagram that was sent with the kit or online! HELP!!!
You're gonna have to post a pic of it - can't really tell from what you have described. Mike - the cleaner was just "Purple Power degreaser" from Autozone.
Glad you figured it out. I wouldn't throw the carb cleaner away...... It's unlikely There is anything wrong with it. Soaking a carb is usually not enough to clean out the ****. neither is blowing out all the p***ages with air. You also need to run soft copper wire through all the p***ages. Byp***ing this step almost always results in something being left behind. Especially in an old carb that hasn't been apart in a long time. The purple cleaner is great stuff, I use it all the time, but you have to be careful with carbs because it will desolve the castings. Which includes changing the size of orifices and p***ages. Relying too much on it can ruin the carb, so be carful. I use it as an initial cleaner only on carbs that I just got.... real crud monsters. Rich
Ryan, Only two places the plugs come from on a 1904. If you are refering to the 1/4" diameter br*** one. 1) in the end of the main well economizer p***age tube. 2) on top of the main well in emulsion tube. Picture attached. Common for the plug in the economizer tube to fall out. I expand the plug a few thousands using a tapered pin and vise. Then press it back in. Actualy had it happen to me.
I had the same problem with the 1904 dripping gasoline on to the throttle plate. I could not idle it down much below 1000rpm. Carb rebuilder in Pittsburgh sez that this is how it is. I took the carb back off for the 7th time and soaked the metering module in purple degreaser from 'Car Clean' for about an hour. Rinsed it and dried it twice and blew out the openings. Back together and it idles smooth at 450rpm. !!!!!Thanks to ALBUQ F-1 above for the answer to this puzzle!!!!!!!
The Jalopy Journal
