Holley 1904 won't idle correctly

[Pete W]

Hi,

I set my timing and adjusted my Holley 1904 carb and I cannot get the car to idle correctly. First, the manual states that you turn the mixture screw back 1 1/2 turns and then turn it in to adjust. I have back the screw in at least 3 turns to get it to idle. I also have to turn in the curb idle almost all the way with the fast idle cam completely off of the screw, not on the last step. It also sputters and hickups bit, but not bad. I put in new ignition parts(points, caps, etc.) and rebuilt the carb but it did this before I rebuilt it. Could it be a timing issue? Maybe fuel pump? Hopefully I am not adjusting it correctly.

Thanks,

Pete

 

[addo]

Pete, have you ensured the dwell is OK on your ignition? Also check each lead for adequate sparking, and your plugs both for fouling and correct gapping. Then confirm TDC matches your balancer, and check the base timing.

 

[Pete W]

Thanks for the reply addo. I never bothered to check the dwell. I did set the point gap and check and set the timing. What exactly is dwell?

 

[addo]

Dwell is a better setting method for the points, than point gap. It reflects how many degrees of rotation the points are closed for.

 

[Mercury Mike]

Addo how do you check the dwell?

 

[Pete W]

To add to that question.....

I believe you check the dwell with a dwell meter. If you find that it does not jive with what the manuals specs, what do you do then? I'm thinking you adjust the point gap even though it might not be the same figure that the manual suggests. Do you open the gap wider if the dwell is greater than spec of visa versa?

 

[addo]

That's correct on both counts. Points gap is an approximation to the correct dwell, but really dwell (rather than points gap) is what matters. So you adjust for it. Wear in the distributor can be a contributor to mismatching of these two attributes.

Many of the older style engine tune up meters have a dwell function on the scale. You just need to be sure of reading the 6 cylinder one!

Cheers, Adam.

 

[pedal2themetal45]

Yes setting the dwell can be a PITA. Cause you have to set it put it back together and start the car to see where it actualy is. Then repeat if it aint corect but its worth it..
and I beleve the smaller the gap the bigger the Dwell number.
What I would do is
run motor to see what the dwell is
then Pull the cap and rotor.
Hook up the Dwell meter
run a test
You have to crank the motor over to run a test dwell. Because the neddle well bounce (because the motor aint running) you well see where it is in the bounce then set the right dwell accordingly.
reinstall cap and rotor and check to see how close you are..
good luck
tim

 

[Mercury Mike]

When I hook my old school RPM/Dwell meter up, will it read from the coil and everything, same hook up?