Countdown to Start day

[Fabrice]

Champagne!

If it ran fine 5 minutes, if you have no fuel leaks. Since I saw how rusty unused fuel lines can become from within, my first thought would be to inspect the fuel filter.

Then the usual suspects, coil, vacuum tubes etc...

 

[kcmash]

There was fuel leaking through the base of the carb on the drivers side.  The coil and electronic ignition are new Flamethrower 3 setup.   Kinda lost on this again.  Something doesn't feel right.  

 I need to have a trusted friend come for a start day with me and get some fresh ideas.

kcmash

 

[kcmash]

Need Some chime in here!!

OK, I started the car again today and its the same story.  I need to bounce some ideas.

1)  The car started, white colored smoke upon first start as she fired up. (Black would be gas, blue oil water is white.) (Hold that thought)

2)  The car ran good after about a 30 second warmup at around 1800 RPM.

3)  I set the idle to about 1000 rpm and she was idling good, slight cam lobe and seeming like nothing is wrong.  Oil pressure is good, temp gage is not registering anything, so I have no idea on the temp.

4)   About 4 minutes in, something changes.  The idle changes a little she knocks a little and dies.  Re-start and it won't idle.

I am thinking one of 2 things here.  

First, the vacuum advance tree on the front of the engine.  I have 2 connections, the lower goes to the vacuum advance on the distributor, the top I have connected to manifold vacuum.  Should that be routed to the metered carb vacuum instead?  My theory is that the temp switch activates, the vacuum advance gets a full dump of manifold vacuum, she advances, sparks and dies.  What do you think?  What tests should I run?

Second theory, the thermostat opens up and water goes somewhere it is not supposed to go.

 

[Fabrice]

Its hard to tell without the sound.

The old 2V on my 73, very poorly maintained for 17 years before me had developed a small hair thin break into one cyl chamber. It matches the description. The engine would start with a whitish exhaust for a few then run fine, and as it got hotter, it would gets a very specific rhythm/sound if you try hold it on the foot. Missing a cylinder but without miss firing. And would die if I would not hold it.

Not claiming that's the case tho. Plenty to check before that, even without any temp readings.

If coolant is involved

That another way to say that the coolant exits the radiator/hoses/block circuit, therefor there would be a difference in the coolant level.

Note that you don't need much to get this fx, try fill radiator and mark as precisely as you can or take a pict when cold. Then compare after it ran and failed.

Remove the oil breather/fill cap near cyl 5 and insert your finger so you can cope on the top inside the valve cover. If you have "mayonaise" on your finger, you have water entering the oil system (or you haven't changed your oil for ages). sometimes you can also see condense on the oil stick. If your oil is contaminated then I'd say a blown head gasket could be a candidate too (have you changed/touched the heads?)

If you remove the other breather/cap, near cyl 4, you would get lots of fumes when the engine runs after a very short period of time.

Inspecting the plugs should also tell you more. At least one plug isn't sharing the same aspect as the others if coolant is added to the mix.

To test the vacuum, I'd do simple test first: close/plug them all, let the carb only have the vac from the intake behind the carb.

and let it idle. Best would then to have one vacuum gauge to read the pressure when it runs.

In case you have no plugs avail, a poor man's way to make one is to cut a hose of same line diameter say 1.5 inch long and insert a screw that fits very tight in it on one side.

Plenty more tests possible and others will come with ideas but this would be what I'd do first.

 

[kcmash]

Thanks for the reply.  I have it back inside now, but before closing for the day I did the following:

Tried plugging all ports and running with nothing to the vacuum advance.  I couldn't really get it to run at all.  I tried advancing the timing to compensate and it really didn't help much.

I tried bypassing the temp switch and running the vacuum advance from the metered carb port.  Same as above.

If I start it and keep fanning I can keep it running for about 20 seconds  then it acts like it runs out of gas and dies.  A couple pumps and I can repeat the cycle.

If I hold it around 2000 rpm there is a distinct (but light) vibration in the system.  Not sure if that is a miss or not.

I did do a compression check on the cold engine last year when trying to diagnose and everything looked awesome.  Not sure what to look for next.

kcmash

 

[Fabrice]

mmm, for the carb/vacuum, you'll need to wait till the "original carbs" gurus are awake.. My 73 is having all kept to the minimum for the engine vacuum circuit (efi/intake, efi/dist) and I have a permanent vacuum reader on the engine. No complex circuit I could use as a ref to help you.

The "vib" is likely a missing cylinder at a given time.

Compression tests are in coolant leaks cases sometimes ok or even better, as the fluid can help to seal.

Its very hard to help without seeing/hearing. In day light, could you set your phone behind the car so it records your exhaust when you start cold?

or try to record the moment you get the problem?

 

[kcmash]

Any other love here?  I need a few more suggestions

Thanks!

kcmash

 

[Don C]

The entire cooling system is under pressure as it warms up, the thermostat just redirects the flow of coolant, it doesn't have enough pressure, on it's own, to force coolant into any place it shouldn't be.

When the engine is cold, pressurize the radiator with a radiator pressure tester. This will let you see if coolant is going places where it shouldn't, when the engine is cold.

A combustion leak detector kit will tell you if you have combustion gases in the coolant, which would show a blown head gasket or cracked head.

Connect your distributor vacuum advance directly to ported vacuum on the carburetor, see what happens. Connect it directly to manifold vacuum and see what happens.

When the engine is warmed up and the problem starts, pull the fuel hose off the carburetor and connect it to a pressure gauge and crank the engine to see if you are getting fuel to the carburetor.

Get a spark plug tester and check your spark when you start having the problem.

What kind of ignition do you have? Coils and condensers can break down when they warm up.

Connect a vacuum pump to your vacuum advance so you can control it and the amount of (vacuum) advance you're getting.

When was the last time your carburetor was rebuilt, and has it set there for very long with fuel drying in it and turning into varnish, or has it had gas laced with ethonol in it?

A lot of possibilities, and each one has to be ruled out systematically.

 

[kcmash]

View attachment 41086View attachment 41087View attachment 41088View attachment 41089I may have found the problem!!

Pulled the old carb today to put a newer larger one on and found some interesting stuff underneath.

Not sure if I attached the picture correctly, but I found the following.

1)  The thin gasket used has an area that has eroded away under the rear of the carb where the ports from the carb run.

2) Discoloration under the front of the carb, indicating that the front did not seal properly. Matching discoloration on the bottom side of the gasket.  This is over what appears to be a major vacuum circuit in the intake.

3)  The older gasket was a very thin cardboard sheet.  Did I not torque the carb down correctly?  Can my old carb be warped?  Can my intake be that messed up?

3)  A question for the experts.  Will the Single Plane, thicker gasket shown in the pics be suitable for a Holley install, or do I need a 4 Window gasket to match the carb to the intake.

Quick replies are appreciated so I can get parts today if possible!

kcmash

 

[barnett468]

I may have found the problem!!

Pulled the old carb today to put a newer larger one on and found some interesting stuff underneath.

Not sure if I attached the picture correctly, but I found the following.

1)  The thin gasket used has an area that has eroded away under the rear of the carb where the ports from the carb run.

2) Discoloration under the front of the carb, indicating that the front did not seal properly. Matching discoloration on the bottom side of the gasket.  This is over what appears to be a major vacuum circuit in the intake.

3)  The older gasket was a very thin cardboard sheet.  Did I not torque the carb down correctly?  Can my old carb be warped?  Can my intake be that messed up?

3)  A question for the experts.  Will the Single Plane, thicker gasket shown in the pics be suitable for a Holley install, or do I need a 4 Window gasket to match the carb to the intake.

Quick replies are appreciated so I can get parts today if possible!

kcmash

Those holes in front have hot gas from the exhaust which will burn a hole in the paper gasket. They do not go into the intake tracts. Also, it looks like there will be a huge air leak with the gasket you show.

You can use the 4 hole type holley gasket or get an original one. fel pro makes the thickest ones but they make two different ones that have different hole sizes . use the one that has the holes that most closely fit the id of the hole in the intake. It is possible that you might get a slight exhaust leak from the area of the exhaust holes but it won't cause a vacuum leak with a 4 hole gasket unless the base of the carb has a channel that will overlap the exhaust channel.

 

[barnett468]

I may have found the problem!!

Pulled the old carb today to put a newer larger one on and found some interesting stuff underneath.

Not sure if I attached the picture correctly, but I found the following.

1)  The thin gasket used has an area that has eroded away under the rear of the carb where the ports from the carb run.

2) Discoloration under the front of the carb, indicating that the front did not seal properly. Matching discoloration on the bottom side of the gasket.  This is over what appears to be a major vacuum circuit in the intake.

3)  The older gasket was a very thin cardboard sheet.  Did I not torque the carb down correctly?  Can my old carb be warped?  Can my intake be that messed up?

3)  A question for the experts.  Will the Single Plane, thicker gasket shown in the pics be suitable for a Holley install, or do I need a 4 Window gasket to match the carb to the intake.

Quick replies are appreciated so I can get parts today if possible!

kcmash

i will hopefully have an answer for you in less 30 minutes in case nobody else replies by then.

is it a typical aftermarket square bore holley?

is that what was on there before?

those holes in front have hot gas from the exhaust which will burn a hole in the paper gasket. Also, it looks like there will be a huge air leak with the gasket you show.

 

[kcmash]

So the big openings in the front are for an exhaust crossover?

I also noted I will need a thick gasket for the Holley so the rear bowl feed tube does not bottom out on the intake.

Glad I found this issue!  I may actually get somewhere now,

 

[kcmash]

OK I am frustrated and feeling this will never end.

I finally build my own hose connections to the Holley today because the dual feed line would not stop leaking.  So the good news is that I don't have a fuel leak.



So let's start the car, right?  Well I crank and crank with no fire at all.  Check the #1 with an induction timing light, no spark.  Check the coil wire with the same light and get a nice strobe.

Flashback, I decided to go with the Pertronix Ignotor III and a new Flamethrower coil.  I had heard nothing but good.  So now I have a grand total of about an hour runtime on the engine and no spark FROM the distributor.





So I read some tips and check the wires.  Here is where i need help.  The red wire slides loosely over the terminal on the coil using the Pertonics supplied ring terminal.  The factory power wire from the original car harness has a 90 degree shrouded boot to connect to the coil.  If I put a nut on the coil terminal, the boot will not slide on.  When running before I used the boot connector to "trap" the ring terminal to the coil post.

1) Do you think the loose power ring terminal is the culprit for the Ignitor module to not be firing from the distributor?

2) Is there a way to connect the ring terminal to the coil with a longer standoff? 

3) Do I have to cut the original boot from my harness to use this system?

Is there a way to make sure the Ignitor is still good?  What electrical tests should I do?

kcmash

 

[Duncan Mach72]

You really need a more secure connection. As it is now, a bit of dirt or corrosion & you won't have a circuit.

You really need to cut off the ring terminal, cut the original lead off a few inches back, splice both leads together to the one socket (or boot as you call it).

Also, did you remove or bypass the pink resistance wire from the ignition switch? The Pertronix needs direct 12v feed I believe. You know on the original circuit the coil has a non-resistor feed from the solenoid when cranking and then the resistance feed when running? If you only have it connected to the 'run' position it won't spark while cranking. That one caught me out.

 

[SVO2SCJ]

YEs it is likely that the "yellow" boot ISN'T 12V constant !! Run a dedicated 12V wire (temporarily) and try.

Mark

 

[73pony]

They sell a solenoid kit to get the 12v without hacking up wiring.

Also the Pertronix III is garbage. Just ask me. You can also ask a couple other members on here. Or search the forum.