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Problems starting
https://slantsix.org/forum/viewtopic.php?t=10815		 Page 1 of 1
Author:  Guest [ Thu Nov 04, 2004 6:08 am ]
Post subject:  Problems starting
The car has been having trouble getting started, but if I keep trying it usually starts. I have to crank it over and over and over and pump the gas like mad.... then it might start. It has gotten worse with the cold weather. This morning was 35 degrees and it wouldn't start at all. Same thing yesterday, but I finally got it to start around noon.

I have changed:
fuel filter and air filter
spark plugs and wires
distributor cap and rotor bug
rebuilt the carburator
set the valve lash

None of this has really helped. In fact I think it is worse now. Since I rebuilt the carburator I have a high pitched whining sound that I suspect to be a vacuum leak. I replaced all the vacuum lines, but the sound remains. It comes and goes. I think the carb might be leaking at the throttle shaft.

It also has a really bad exhaust leak. The flange on the pipe is warped and needs to be groung flat. However, the car had the starting problem before the exhaust leak.

I am thinking the timing may be off, and the starter might be getting weak. Is there something obvious that I am overlooking? What should I try next?

Almost forgot, the car has been converted to electronic ignition, so there are no points to set.
Author:  Slant6Ram [ Thu Nov 04, 2004 6:26 am ]
Post subject:  Choke
What is the choke doing during all this? I doubt a leaking throttle shaft would make that big of a difference when cold starting.
Author:  Joug_Fin [ Thu Nov 04, 2004 12:46 pm ]
Post subject: 
I think that you should check that accelerator pump is working. You just look inside the carburetor if it is spraying gasoline when you pump gas. Of course you do that when engine is not running.
Author:  Jimluw [ Thu Nov 04, 2004 1:07 pm ]
Post subject: 
Thanks for the tips. It has a new accellerator pump. I know its getting gas because I can smell it after I try to start it, but I haven't looked down the carb while it is being started. I will check it out.

I also read the article on setting the choke. I'm pretty sure I didn't get it exactly right when I rebuilt the carb, so I will work my way through that procedure. Thanks again.

So, everyone is in agreement that it is a carb issue? Should I not mess with the timing or the starter? I guess it couldn't hurt to set the timing, but could it cause my symptoms?
Author:  Joug_Fin [ Thu Nov 04, 2004 1:39 pm ]
Post subject: 
If timing is much away, it will be very hard to start. If You can make it run , it's easy to check timing. If you can't make it run, loosen distributor bolt and ask someone else to crank while you turn distributor. That way you will find timing so near that you can start it and adjust timing.

And that accelerator pump test you can make just by hand, when engine is not running.
Author:  Slant6Ram [ Thu Nov 04, 2004 1:47 pm ]
Post subject:  Timing
Yes I think it's a carb/ choke problem, but it's only a guess based on your description. I can't be sure, but I feel it's the place to start.

Yes, incorrectly set timing can make a car hard to start, but not typically in the way you have described. It doesn't hurt to check the timing setting, but if it was starting O.K. and now doesn't start easily, but runs fine once started, then I doubt timing is the issue.

When did the problem begin to occur, and what did you do before it began? Did it ever start well while you've owned it?

You may have killed your battery in the process, so I would always have it charged and/or tested before I buy a new starter.

The correct procedure to start your motor cold is to press the gas pedal all the way to the floor once. that should set the choke to the closed position (get out of the car, take the air filter off and check the choke) Next, turn the key to crank the motor. I usually press the gas once more while cranking and nothing else is required.

Let us know if the choke is closing.
Author:  Jimluw [ Fri Nov 05, 2004 9:08 am ]
Post subject: 
Slant6Ram, I bought the car about a year ago. I drove it all winter long. It did in fact start the way you described. Hit the gas once or twice, turn it over, and it would fire right up. Even in the coldest weather.

The problem seems to have been gradually coming on. It was pretty hard to start before the weather got chilly. I thought it just needed a goog tune up, so I changed all the parts I listed in the first post. The problem has continued to worsen.

I checked some things out last night.

Joug Fin, I could see the accellerator pump working. Thanks.

Slant6Ram, The choke is closing all the way. The vacuum pod is working. If I hit the gas once, it does set to the highest cam setting. With the choke linkage set at the highest cam setting the choke plate is closed. The car will not start with the choke plate closed. I propped the choke plate open and finally got the car started. Then I gradually closed the choke plate. The further I closed it, the worse it ran. If I close it all the way while it is running it will die. It seems that with the choke plate closed it cannot get enough air to run.

So, I am confused. The choke is supposed to help it start. But, with the choke operating correctly, the flap is shut while you start the car? The car will not start until I open the flap. With the flap closed, where does the necessary air come from?

I did notice that the whistle sound is coming from the vacuum port that leads to the vacuum pod. If I unhook that port the sound goes away. If I hook up the hose or block off the port, the whistle comes back. It is getting enough vacuum pressure to operate the vac pod. I have the pod hooked the rear port. The front port is connected to the air cleaner (Hmm, is this where the air I asked about comes from?).

The carb is a Holley 1920.

Thank you very much for your help. I don't know what to do next, other than continue playing with the choke settings until I understand exactly how it works. The choke looks like it is doing what it should, but is not giving the desired effect. Any more suggestions?
Author:  Slant6Ram [ Fri Nov 05, 2004 11:23 am ]
Post subject: 
Quote:
with the choke operating correctly, the flap is shut while you start the car?
Yes, the closed choke helps the engine draw in a richer fuel mixture which is needed when cold starting.
Quote:
The car will not start until I open the flap.
it should open itself as the vacuum builds, it should cause a properly working/ adjusted vacuum choke pull off to open the flap slightly.
Quote:
With the flap closed, where does the necessary air come from?
a small amout of air should always be entering through the PCV system, a little more should leak around the choke flap.

This is good, your tests have eliminated problems with lack of fuel, now you need to check the remaining vacuum and choke parts.

Have you connected your vacuum lines to the correct places?
Is the vacuum choke pull off functioning and adjusted?
Is the pcv port on the carb drawing strong vacuum? (clogged port or incorrect gasket)
Is the pcv valve working to regulate flow? (a new one is only $3)

You are very close!!!
Author:  Jimluw [ Fri Nov 05, 2004 12:34 pm ]
Post subject: 
Thank you for your consistant replies!
Quote:
Have you connected your vacuum lines to the correct places?
I think so. On the Driver's side of the car there are two small vacuum ports. The one towards the front of the car goes up to the air cleaner. The one towards the back goes to the vacuum pod for the choke.

On the Passenger side there is one small vac port which goes to the vac advance on the distributor. One large port is connected to the PCV valve. I'm not too sure about the rest. I think there is only one more...?


Quote:
Is the vacuum choke pull off functioning and adjusted?
Not too sure on that one. Are you referring to the vacuum pod? If so, I can see that vacuum pressure does affect it. When it has vacuum it pushes the pod out. When there is no vacuum, it pulls the pod back in. I am not sure if it is adjusted properly or not. I read the article on choke adjustment. I tried to do it last night. I am not sure if I understand it correctly. It seems as though it is doing what it is supposed to do. I will experiment with it some more tonight. Until I am certain about it, I cannot know if it is adjusted correctly or not.

Quote:
Is the pcv port on the carb drawing strong vacuum? (clogged port or incorrect gasket)
I haven't checked the PCV vac pressure. Good idea. The port should not be clogged because I did an extreme cleaning job when I rebuilt the carb. You are referring to the gasket under the carb right? The kit came with two, I matched the gasket to the old one. It was the one with extra holes in it. It was even marked TOP and FRONT, so I am pretty sure I put it in right.
Quote:
Is the pcv valve working to regulate flow?
I put a new PCV valve and all new vac lines.

Okay, here is the plan so far.
Check the vac pressure to the PCV.
Check to see that the vac pressure is flowing through the PCV.
Double check the gasket.
Try to adjust the choke again.
Try to gain a complete understanding of how the choke system works.

I will also look into any other suggestions you might have. Thank you again for the help!
Author:  Jimluw [ Fri Nov 05, 2004 12:35 pm ]
Post subject: 
erased...
Author:  skraecken [ Sun Jul 23, 2006 12:42 am ]
Post subject: 
The choke could be set to tight.
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