Fails to choke at start

[wncrjb]

Re: Fails to choke at start

Plus, if you have to go into the carb, you will be better off getting a new float too, which is not included with many re-build kits.

 

[gene8084]

Re: Fails to choke at start

I wondered about that. This Carb List 6317-1 doesn't seem too common. I'm hoping I can find the parts.

 

[Boomyal]

Re: Fails to choke at start

I would check the accelerator pump linkage and replace the diaphram if necessary before I tore the carb apart.

 

[gene8084]

Re: Fails to choke at start

Report!

I rebuilt the carburetor. The pump diaphram was a mess and the power value was in bad shape.

Once I saw that I kept going, soaked, cleaned, and replaced everything I could with the kit. The kit from aftermarket.com turned out to be very good.

I followed the disassembly and assembly instructions in the manual to the letter, took copious notes, digital pictures, and with only one exception I had every gasket and needle they recommended. (they = Clymer Mercruiser Shop Manual)

"...Now I have the two distinct streams of fuel squirting from the 'uvulas' down into the venturis and I confirmed that I'm getting full actuation on the accel pump lever..."

I'm still having trouble starting, but I hope some adjustments will resolve that now that I know I'm starting with a clean carb. It starts well once it's warmed up so I hope I'm getting close.

Thanks for all the tips.

I'm certainly open to anyting else you can add for next steps (fine tuning) to resolve the cold starting problems.

 

[180shabah]

Re: Fails to choke at start

Now we go back to the beginning and readjust the choke.

 

[Boomyal]

Re: Fails to choke at start

....and the power value was in bad shape.

Did the kit come with the proper marine sized power valve?

 

[gene8084]

Re: Fails to choke at start

Yes, near I can tell. It was visible in the pictures I attached in the original thread. The kit was for the Holley 2300 or 6317. I have the 6317.

I'm not sure I know what you mean by "marine sized". It certainly appeared almost identical to the one I was removing.

 

[Boomyal]

Re: Fails to choke at start

Yes, near I can tell. It was visible in the pictures I attached in the original thread. The kit was for the Holley 2300 or 6317. I have the 6317.

I'm not sure I know what you mean by "marine sized". It certainly appeared almost identical to the one I was removing.

They look identical gene but they have different values that are stamped on the valve. Number like 6.5 etc. etc. These determine how much fuel is allowed to flow at low vacumm acceleration.

Take a look at the numbers on each of the ones you have, old and new. I don't recall whether the higher or lower number is suitable for a marine app. All I know for sure is that auto is different than marine due to the different fuel requirements for marine acceleration.

Your marine list number should show what the carb came with. If in doubt, you can always call Holley, with the list number and they can tell you which valve you should have. They can also verify that it is a marine carb.

The power valve is not going to affect your starting but you do want the right one installed for proper power on acceleration.

 

[gene8084]

Re: Fails to choke at start

I checked the old one and I don't see any numbers/letters on it. The new one is in the carburetor. However, I don't recall seeing any writing on it at all. I gave it a pretty good look before assembling to be sure it was a match.

I tinkered with the electric choke adjustment a bit and got it to start today without manually choking. I had to give it some gas to keep it running. It ran for a while at low / mid speed, don't recall the RPM's, but it quit after leaveing it idling for a short time. A couple more tries I got it to run again but ended up with a tired battery and out of ideas...I called it a day.

A friend suggested that the failure to idle could be a bad PCV valve. That's a cheap test so I'll try it. I can hear the ball shaking around so I doubt that's it.

After this I may have to resort to a mechanic $$$. I'm afraid I've reached the level of my incompetence

 

[gene8084]

Re: Fails to choke at start

I'm afraid I've come full circle. Rebuilt carb, choked or other wise it just won't start.

I feel like I'm missing something fundamental. It sputters, tries to start, and doesn't catch regardless of where I set the choke.

I've never touched the timing, but is there a chance that my timing is drastically off and not knowing it's history should approach this as though the distributor was just put in and align the rotor with #1 while the piston is at the top of its stroke?

 

[a70eliminator]

Re: Fails to choke at start

That Ford should fire right up pcv valve or not, carb power valve size means nothing at this point, did you put a new gasket below the carburetor spacer? If you didn't move the distributor timing is a non issue. Do you get backfire or just sputters? Go back to the basics, verify TDC of #1 cylinder, rotor should be pointing to fire #1. Double check fireing order and wire placement, you did mention a complete tune up right? it's easy to get those messed up. More than likely it's just something simple.

 

[a70eliminator]

Re: Fails to choke at start

I just noticed in your original post that you had replaced points with an igniter, pertronix Ignitor? They do burn out if you play around with stuff and leave the key in the on position for too long, the new Igniter II did not have that problem, you mighnt want to try putting points and condenser back.

 

[gene8084]

Re: Fails to choke at start

That Ford should fire right up pcv valve or not, carb power valve size means nothing at this point, did you put a new gasket below the carburetor spacer? If you didn't move the distributor timing is a non issue. Do you get backfire or just sputters? Go back to the basics, verify TDC of #1 cylinder, rotor should be pointing to fire #1. Double check fireing order and wire placement, you did mention a complete tune up right? it's easy to get those messed up. More than likely it's just something simple.

The PCV valve didn't make a difference.

Yes, new gaskets everywhere. Between:

1. the intake and throttle body, the
2. main body and throttle body, the
3. metering block and main body, and
4. the fuel bowl and metering body.

I guess I need to step back. Funny thing is I had it running, not well, but running after all the carb and tune up work.

Primarily sputters, but its possible there was a small backfire/pop when starting.

I'll certainly trace the wires and double check that the rotor is pointing to #1.

On your other point, "the Ignitor", yes, it's an Ignitor II.

This should be sooo simple (very frustrated).

 

[Silvertip]

Re: Fails to choke at start

Never mess with choke adjustments on a warm engine. It needs to be set on a stone cold engine. If the choke is opening at ambient temperature on a cold engine, it's not adjusted properly. Move the thottle forward to set the choke. Loosen the choke screws and rotate the disc so the choke just closes. Now start the engine. Immediately, the vacuum operated choke pull off should pull the choke partially open. It should open so that a 5/16 diameter drill bit can be inserted between the edge of the choke plate and the carb throat. As the engine begins to warm the electric heater in the choke housing opens the choke the remainder of the way. If the choke doesn't open after intial start the pull off may have a ruptured diaphram or the "U-shaped" linking needs to be adjusted. Do not adjust the disc for the initial opening. It has nothing to do with the pull-off function.

 

[Silvertip]

Re: Fails to choke at start

Never mess with choke adjustments on a warm engine. It needs to be set on a stone cold engine. If the choke is opening at ambient temperature on a cold engine, it's not adjusted properly. Move the thottle forward to set the choke. Loosen the choke screws and rotate the disc so the choke just closes. Now start the engine. Immediately, the vacuum operated choke pull off should pull the choke partially open. It should open so that a 5/16 diameter drill bit can be inserted between the edge of the choke plate and the carb throat. As the engine begins to warm the electric heater in the choke housing opens the choke the remainder of the way. If the choke doesn't open after intial start the pull off may have a ruptured diaphram or the "U-shaped" linking needs to be adjusted. Do not adjust the disc for the initial opening. It has nothing to do with the pull-off function.

Lastly, are you pumping the throttle lever a time or two to give the engine a little extra fuel when cold. When warm, advance the throttle a little to give the engine a little extra air. Heat soaking tends to flood engines.

 

[gene8084]

Re: Fails to choke at start

... Go back to the basics, verify TDC of #1 cylinder, rotor should be pointing to fire #1. Double check fireing order and wire placement, you did mention a complete tune up right? it's easy to get those messed up. More than likely it's just something simple.

You got me thinking.

I was extremely careful in patching cables from the old distributor cap to the new and installing new plugs, so I'm sure I didn't cross up a cable...

This morning I went out to have a quick look before work. I traced #1 from the plug to the cap ... and as I looked counterclockwise I saw that the next cable was going to the same side of the block, … surprisingly it was to plug 3.

I went back and traced all the wires and it appears my 302 is wired like a 351. I can only assume they knew something that I don't or they goofed and used the wrong firing order.
351 = 1,3,7,2,6,5,4,8
302 = 1,5,4,2,6,3,7,8

Given this ah hah I realize I'll have to validate #1-rotor alignment, but I'm still not sure whether this is a problem which would explain the symptoms I've been experiencing or it's simply a case where this engine has a 351 cam.

I work alone so I'll have to find someone to help me test to determine whether I should have the 351 wiring order or a 302.

I'll report back...

Thanks for the clear headed back to basics thinking

 

[gene8084]

Re: Fails to choke at start

... Move the thottle forward to set the choke. Loosen the choke screws and rotate the disc so the choke just closes. Now start the engine. .

what does it mean to set the choke?
I'll certainly try this, but I think I have and it will just sputter and try to start.

... Immediately, the vacuum operated choke pull off should pull the choke partially open. It should open so that a 5/16 diameter drill bit can be inserted between the edge of the choke plate and the carb throat. .

What's the vacuum operated choke pull of?
Where is it?

... As the engine begins to warm the electric heater in the choke housing opens the choke the remainder of the way. If the choke doesn't open after intial start the pull off may have a ruptured diaphram or the "U-shaped" linking needs to be adjusted. Do not adjust the disc for the initial opening. It has nothing to do with the pull-off function.

I'm afraid your using some terms I'm not familiar with...
ruptured diaphram? which diaphram?
disc, do you mean the electronic choke?
u-shaped linking inside the electronic choke or on the mainbody to the electronic choke?

Lastly, are you pumping the throttle lever a time or two to give the engine a little extra fuel when cold. When warm, advance the throttle a little to give the engine a little extra air. Heat soaking tends to flood engines.

Yes, pumping the throttle, and it helps, but won't stay running long enough to do or adjust anything else. One day I can give it some fuel to keep it running, but ultimately I'll try to bring it to an idle and it quits or I can't get it running long enough to come up to temp.

Sorry there isn't a question in here. I'm stumped.

 

[a70eliminator]

Re: Fails to choke at start

It would be very easy to verify the firieng order and then you will know for sure, just bring #1 to TDC rotor points #1 next turn the engine with a breaker bar and watch either #3 for 351 come up, or #5 will come up. Just remove the plugs and use a piece of wooden dowel or a pencil, stick it into the cylinder and feel for the piston comming up to TDC.

 

[Haut Medoc]

Re: Fails to choke at start

Pull the flame arrestor off, note the position of the choke plate.....
Pump the throttle, the choke should close.....
Stick a pencil in it, to keep it slightly open.....
Start the engine......
Run it at 1300rpms, after it has run for 20 seconds, put a wad of duct tape in the linkage to keep it (choke plate) wide open......
If you have a '74 888 your firing order is 1-3-7-2-6-5-4-8......
After you bring it to TDC, do what A70 eliminator suggests, but I will bet the correct order is the one above......​

 

[Silvertip]

Re: Fails to choke at start

You really need a service manual sir. That said -- I'll give you a brief overview. Setting the choke means moving the throttle forward to allow the choke plate to close. Whether or not it actually does is not important at this point. The point here is that you can't adjust the choke if the choke is not "set" (allowed to close). Now if the choke plate is not fully closed, adjust the disc. Then start the engine. When the engine starts, it develops manifold vacuum which is fed to a choke pull off. Vacuum acting on the choke pull off diaghram sucks the plunger inward, pulling on a linkage that pulls the choke plate open a little to allow the engine to idle properly. If the diaphram in the choke pull off is ruptured, you have a vacuum leak and the pull-off cannot operate so the choke remains fully closed hence the rough idle or no idle. On some carbs the choke pull-off is built into the carb itself and operates via a vacuum piston. Then the choke heater (the electric heating element behind the disc) begins to open the choke fully. If that's not working the choke will not open either. There you have it. Perhaps now you can understand the value of a service manual because this description would be accompanied by pictures. You might make a trip to the library as they often have service manuals you can check out.