Smooth Running Then...

[Roundeie]

'72 with new plugs, 3 month old battery, no ignition probs. stopped at light on way home and stalled. Rpm dropped to 30 then tails to zip unless holding pedal down a bit. Sounds like its missing.

Checked all wires etc.

Fuel at 1/2 tank

Any guesses? Could limp home in fits and starts just looking for thoughts

[Rocan]

check your points... sounds like they are worn out. I doubt its fuel if its missing. Recheck your ignition timing and pull the plugs to see if they are fouled. 

[Swiftus]

How hot was it today? Was it raining?

 

Points and cap are the easiest to check first. Then I would move on and look at the fuel, see if any crap is in the filter (hopefully you have a clear one). I doubt its fuel but who knows.

 

Is the car hard to start? Does it get better or worse as it warms up? Has this ever happened before?

 

 

Jay

[Roundeie]

I will check distributor, points. Plugs were installed last weekend and ran fine but will pull again. Thanks

[mikebontoft]

please check points...I just had a hard lesson in that.

[Roundeie]

Pulled and cleaned plugs (a little oily), replaced points with new, static timed. No changes. Car idles with RPM needle just above 0. Light white smoke at startup. Where to next?

[Roundeie]

How hot was it today? Was it raining?

 

Points and cap are the easiest to check first. Then I would move on and look at the fuel, see if any crap is in the filter (hopefully you have a clear one). I doubt its fuel but who knows.

 

Is the car hard to start? Does it get better or worse as it warms up? Has this ever happened before?

 

 

Jay

The outside temp was mid 80's, car is not hard to start. Occurred for the first time yesterday on return trip from work. Freeway driving, not a problem until pulling off exit ramp late afternoon 5 ish.

Fuel filter is Mahle metal housing.

After points changeout it idles but at very low RPM. Manual choke btw.

[FunkyLaneO]

the oiliness on your plugs and the white smoke at startup are likely your rings are a little worn, no biggie, that is not likely what is causing your problem. 

 

It is either ignition or fuel so if you can rule out one then it is the other, it is usually easiest to check the ignition so do that first, new points and condenser and check the dwell and set the timing, make sure all the ignition wires are firmly seated on the plugs, if all of that checks out then onto the fuel.  Check for any vacuum leaks and make sure the fuel pressure is good and that your in tank screen and fuel filter are not clogged, pull your idle jet and make sure it is not clogged, if there is a solenoid on the idle circuit make sure it is working.

[bill.in.mt]

Second the need to check your idle jet. Blow it out and see if the idle speed improves.

[mikebontoft]

What if there IS a solenoid on the idle circuit...? how does that one work? is it just a simple on/off solenoid controlled by, maybe a coolant temp sensor?

Edited September 17, 2013 by mikebontoft

[FunkyLaneO]

The solenoid sticks out of the side of the carb (weber), you can't miss it. If it is there then there should be a wire plugged in to it that has power when the ignition is on.  The way to tell if it is working is to listen (or feel) if it clicks when power is applied.  When you turn off the car the solenoid cuts fuel to the idle circuit to prevent dieseling (run-on).

[Roundeie]

No wires here. 32/36 DGV Weber manual choke.

[Mike Self]

Once you've ruled out ignition problems, I'd certainly check the idle jet.  They're pretty small so it doesn't take much to plug it up.  Fifteen seconds to pull and clean.

 

Also...check for a vacuum leak.  There are several vacuum ports on both the carb and the intake manfold.  If your emission stuff has disappeared, they will all be unused except the one that leads to the dizzy's vacuum advance.  Make sure none of the caps have fallen off, and that the carb is tight on its mount. 

 

Finally...pull the vacuum advance hose off the carb and suck on it.  You should feel resistance.  If you don't, pop the dizzy cap, suck again and observe the point plate.  If it doesn't move then your vacuum advance unit is dead and it also is providing a vacuum leak.  Both will affect your idle. 

 

Let us know whatcha find...

 

mike

[Roundeie]

Ok, that was nasty and it didn't move (points plate). Is there a dizzy rebuild kit somewhere? Also, pulled and blew out the idle jet.

The intake manifold has holes everywhere. These can't all need to be plugged can they? Some look like mounting holes but I can't see in them. The carb holes are plugged unless used.

Edited September 18, 2013 by Roundeie

[mikesmith]

You said it'll idle, but very slowly.

 

Is it even, but slow, or rough?  If it's rough, stop the motor, pull the plug wire off #1, lay it on the bodywork somewhere and *stay away from it*. Then try to start the car and see if the idle is "the same", or "worse". Reconnect the plug wire and then repeat for the other three.

 

If for any one wire you get "the same", then that plug is missing.  If you can, swap in a spare plug wire and see if that changes anything. Pull the distributor cap and check the electrode that corresponds to the plug. (Or swap in a known-good cap).

 

Yes, the intake manifold needs to be completely sealed. If you're not sure whether a particular hole is leaking vacuum into the manifold, see if blocking the hole (use a piece of hose and a clamp, or a flat piece of rubber or similar, not the end of your finger) improves the idle.