I just had the carb rebuilt on my 400. Cannot get any rpms out of it, it just starts "missing". I have turned the distributor as I increase rpm but does not help. Also...timed engine by ear and then put a timing light on it, 33degrees off, turned dist to 12 with the light and would not run??? Could the harmonic balancer have slipped? One more....what is the electric switch on the accelerator pedal on a 68 442?

 

are the set screws on the carb adjusted properly?

 

The switch on the accelerator pedal is the kick down for the transmission. What ignition system are you running, points, hei, pertronix,...?

This thread may point you in the right direction as it sounds very similar.

https://classicoldsmobile.com/forums...do-timing.html

 

Adjusted them but did not seem to help so put them back at the setting the carb was at when it came back from the rebuild. Any idea on the correct adjustment?

 

Yes, it could have.

There are also several dozen other possibilities.

We will need more information, starting with whether the balancer has or has not slipped, and what the rebuild specs are.


If you have an automatic transmission, it's the kickdown.

- Eric

 

It is a points system.

 

depends on how your engine is built.usally two and a half to three turns, until it runs the best.

 

Could the coil have any part of this game? It runs fine at lower rpm, but to open it up the secondaries don't even come open.

 

First make sure your dwell is at 30. There are several references for timing on the 400 from 0 @ 725 to 10 deg btdc @ 1250 rpm.

On the carb open the a/f mixture screws to 2 1/2 turns ea and if the engine stalls raise the idle a little to keep it running. Make sure the choke opens all the way when it warms up.

The secondaries generally won't open just operating the throttle by hand.

 

i wouldn[t think so. but the points could be going bad. my 74 acted crazy all the time and take spells of no power, i switched to electronic ignition. and never had problem again.

 

Yes, coil, points, condenser, wires, cap, or rotor could be bad.

Among other things.

We can't use our Kreskin-ometer to diagnose your engine over the interwebs.
That's where troubleshooting comes in.

- Eric

 

The idle mixture screw setting on the carb has virtually NO effect on how the engine runs past idle. Misfiring and lack of RPMs as described are almost always ignition related. Verify the coil, points, cap, rotor, and wiring are in good shape. My money is on bad plug wires or coil.

 

How did it run before the carb work was done? If it ran decently before the work and didn't have the same problems it has now after putting the rebuilt carb on, I would concentrate on that area before changing and adjusting other things. It will just complicate the troubleshooting process.
It seems unlikely the balancer would slip and go bad at the exact time the carb was rebuilt unless the engine had the same problems before the carb was rebuilt........
Now if it ran badly before the carb was rebuilt, then I would agree with Joe, and suspect ignition/ timing issues being the problem. In either case get the timing and or ignition faults squared away first, which would include a check of the balancer, then concentrate on the carb.

 

It ran the same, had the carb rebuilt because it leaked ALOT of fuel. I just bought the car and am in the beginning of going through all of the trouble spots. It really runs fine, just can't open it up and let her rip!

 

My money is still on coil or plug wires. At a minimum, some ignition-related problem.

 

Get a chassis service manual if you do not have one. Go through the ignition system, starting with dwell setting. Verify dwell, then set timing as per manual. You did disconnect vacuum to set timing? Verify wieghts and springs under the ignition rotor move and spring back. If you have a set-back timing light, verify advance.
X2 on what Joe says, ignition trouble, but I would check the above before just throwing parts at it.