Cold Start Issues
Thread Starter
Instructor
Joined: Jul 2014
Posts: 145
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From: Centerton, AR
Cold Start Issues
I have what I believe is a 1967 327 in my 1965 convertible.
I have the Pertronix ignition in it.
The issue is that is is really hard to start cold.
The starting procedure goes something like this:
Crank it for a good 15 to 20 seconds,
Let it sit for a couple of seconds,
Crank it again, and after about 10 seconds, I can hear it turn on it's own a little, like it's trying to start.
Let is sit for a couple of seconds
Crank it again, and after about 5 seconds it will start, run really rough, then stall.
Crank it again, and after about 2 seconds and wildly pumping the throttle, it will start and stay running.
It will then idle nicely.
And when I drive it, there are no issues with throttle response.
After about 10 minutes of driving, if I shut it down for a few minutes (e.g. to get gas), it starts right up, no problem.
Also, interestingly when it's idling, if turn on the headlights (with the Detroit Speed motors), it stalls unless I give it gas.
Any thoughts on the culprit?
Thanks!
John
I have the Pertronix ignition in it.
The issue is that is is really hard to start cold.
The starting procedure goes something like this:
Crank it for a good 15 to 20 seconds,
Let it sit for a couple of seconds,
Crank it again, and after about 10 seconds, I can hear it turn on it's own a little, like it's trying to start.
Let is sit for a couple of seconds
Crank it again, and after about 5 seconds it will start, run really rough, then stall.
Crank it again, and after about 2 seconds and wildly pumping the throttle, it will start and stay running.
It will then idle nicely.
And when I drive it, there are no issues with throttle response.
After about 10 minutes of driving, if I shut it down for a few minutes (e.g. to get gas), it starts right up, no problem.
Also, interestingly when it's idling, if turn on the headlights (with the Detroit Speed motors), it stalls unless I give it gas.
Any thoughts on the culprit?
Thanks!
John
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Before you try to start it do you pump the gas two or three times and then hold the gas pedal half way down to active the choke. That's what the owners manual states you should try. But what does GM engineers know about your car
Safety Car
Joined: Mar 2003
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From: Philadelphia PA
Mine used to exhibit that until I "tuned" it up, new plugs, wires, fuel pump, fuel filter, new lines from the long line up to the carb. And no Petronix, still using points. The couple times I did fire up from cold, it started up rather quickly. Then I had brake issues and now it sits waiting for me to get back to it.
When was the last time the carb was rebuilt?
When was the last time the carb was rebuilt?
Safety Car
Joined: Nov 2000
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From: Clinton Township MI
Cruise-In III Veteran
jkinton,
Besides checking to be sure your choke is setup correctly, it's quite possible your starting issue could be related to your Pertronix. I have the "1st generation" lobe sensor type Pertronix in my '5. Been in there 8-9 years now. No issues. But, with this Pertronix, you don't just get in the car and turn the key to start. The procedure is to "cook" the ignition for 2-3 seconds in the run position before turning the key to start the car. I use that wait time to adjust mirrors and buckle up. She fires up immediately.
Just a thought on your hard starting issue.
Jim
In God We Trust!
Besides checking to be sure your choke is setup correctly, it's quite possible your starting issue could be related to your Pertronix. I have the "1st generation" lobe sensor type Pertronix in my '5. Been in there 8-9 years now. No issues. But, with this Pertronix, you don't just get in the car and turn the key to start. The procedure is to "cook" the ignition for 2-3 seconds in the run position before turning the key to start the car. I use that wait time to adjust mirrors and buckle up. She fires up immediately.
Just a thought on your hard starting issue.
Jim
In God We Trust!
Thread Starter
Instructor
Joined: Jul 2014
Posts: 145
Likes: 17
From: Centerton, AR
Thanks for the responses everyone.
For throttle o starting, I've tried all iterations I can think of: pump once then try to start (per the owners manual for cold start), hold down (per the o.m. for flooded), hold down part way (per the o.m. for warm start), pump two to three times (per experience with 1970 GTO when I was a teenager), pumping constantly (because I was frustrated), and just about every iteration in between.
The best results seem to be to pump once, then pumping repeatedly when it tries to catch.
I will try the trick of leaving it in the "on" position for a few seconds to see if that helps.
Thanks again,
John
For throttle o starting, I've tried all iterations I can think of: pump once then try to start (per the owners manual for cold start), hold down (per the o.m. for flooded), hold down part way (per the o.m. for warm start), pump two to three times (per experience with 1970 GTO when I was a teenager), pumping constantly (because I was frustrated), and just about every iteration in between.
The best results seem to be to pump once, then pumping repeatedly when it tries to catch.
I will try the trick of leaving it in the "on" position for a few seconds to see if that helps.
Thanks again,
John
Melting Slicks
Joined: Jun 2012
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From: Wilton Ca.
As 66Jack asks, is it a Holley? If so, remove the air cleaner (when cold) then pump the throttle once or twice then look to see if the choke is even closing. Could be a weak spring or linkage hanging up.
Gary
Gary
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Thread Starter
Instructor
Joined: Jul 2014
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From: Centerton, AR
Racer
Joined: Jun 2013
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From: Fremont CA
At this point, I would take the key out and get a close look at the primary jets while pulling the accelerator linkage to simulate pumping the gas pedal once or twice. If you don't see any gas being squirted out from the primary jets, your primary fuel bowls could have been gone dry were the gas slowly drained back to the fuel lines/tank. I hear about this issues with GTO's with a non Holley carb. My buddy needs to use starter fluid every time the car sits for a week. From my understanding cranking the engine too long is not good for the starter.
This cold start issue be the reason why you can start fine after the car is warmed up.
Here is video regarding Holley choke adjustments if you don't see your electric choke move the butterfly.
http://www.bing.com/videos/search?q=...262845C9A1ED60
Last edited by irwiny; Jun 10, 2015 at 12:17 AM.
Burning Brakes
Joined: Oct 2012
Posts: 847
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From: Philo IL
John have you done a search in the Forum archives? There are a 1/2 dozen or more similar threads about hard starting issues. Here is but one example of a past thread...
https://www.corvetteforum.com/forums...327-350-a.html
You are not alone with this problem. Take a look at some previous threads discussing this very topic and see if any of them might be helpful to you. I had this problem of hard, cold starts with both my '66's but with my convertible (stock 327, base 300 hp engine) I have resolved it as you'll see in that thread I reference. Starting my L79 coupe is better after I did a complete rebuild of the Holley but it's still not as good as my convertible......yet..... but I'm working to improve it.
It may sound simplistic, but start with the basics and go through everything to make sure your set up is adjusted and operating as per the shop manual i.e. choke set and working correctly, float level set correctly etc. Keep in mind these engines were engineered for different fuel than what is available presently and that itself creates some of these hard starting issues. Evaporation of fuel in the float bowl in a cold engine or percolation of fuel in a hot engine being just some of these starting issues. Keep us posted with your progress.
Thomas
https://www.corvetteforum.com/forums...327-350-a.html
You are not alone with this problem. Take a look at some previous threads discussing this very topic and see if any of them might be helpful to you. I had this problem of hard, cold starts with both my '66's but with my convertible (stock 327, base 300 hp engine) I have resolved it as you'll see in that thread I reference. Starting my L79 coupe is better after I did a complete rebuild of the Holley but it's still not as good as my convertible......yet..... but I'm working to improve it.
It may sound simplistic, but start with the basics and go through everything to make sure your set up is adjusted and operating as per the shop manual i.e. choke set and working correctly, float level set correctly etc. Keep in mind these engines were engineered for different fuel than what is available presently and that itself creates some of these hard starting issues. Evaporation of fuel in the float bowl in a cold engine or percolation of fuel in a hot engine being just some of these starting issues. Keep us posted with your progress.
Thomas
Burning Brakes
Joined: Mar 2001
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From: Alhambra CA
I went through this awhile back with my 65
It turned out to be a bad accelerator pump
You can test this, by taking off the air cleaner and put a bit of fuel down the primary.. Re-install the air cleaner to prevent backfire then try to crank..
If it starts right off, it tells you that either the accelerator pump is bad or fuel is draining from the bowels after sitting
BTW, if allowed to sit for weeks, fuel can evaporate from the fuel bowels and also give this initial start problem
Good luck
Tony
It turned out to be a bad accelerator pump
You can test this, by taking off the air cleaner and put a bit of fuel down the primary.. Re-install the air cleaner to prevent backfire then try to crank..
If it starts right off, it tells you that either the accelerator pump is bad or fuel is draining from the bowels after sitting
BTW, if allowed to sit for weeks, fuel can evaporate from the fuel bowels and also give this initial start problem
Good luck
Tony
Thread Starter
Instructor
Joined: Jul 2014
Posts: 145
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From: Centerton, AR
Thanks everyone for your assistance.
The choke is working.
Jim's suggestion of leaving the key in the "on" position for a few seconds before cranking seems to work.
Best regards,
John
The choke is working.
Jim's suggestion of leaving the key in the "on" position for a few seconds before cranking seems to work.
Best regards,
John
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Army
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Go into the kitchen and get the wife's plastic (picnic) ketchup bottle and put a small vacuum hose on the nipple. Fill the little container half way with gasoline and carefully until you get the hang of it put some gas in the front carburetor bowl vent then see how the car cold starts.
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Army
Great idea. When done, take the hose off, replace the ketchup bottle in the fridge and feign innocence when the wife complains about the taste of your next hot dogs.
Seriously though - gas will eat through some plastics so I'd test that ketchup container first.
Seriously though - gas will eat through some plastics so I'd test that ketchup container first.
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I do use this method on my Holley 3810 if it sits for a few weeks, which is normal.
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Army
Sounds like classic cold-start, fuel starvation to me.
Do tbarb's test; also, with the carb cold take the air cleaner off, blip the throttle by hand and make sure the choke completely closes...if so, then hold the choke plate open with one hand, blip the throttle again SHARPLY and look for a twin sprays of gas from the primary nozzles in the carb throat. If these checks do not work (and tbarb's test does) you have fuel issues for sure.
The above tests should take all of 10 minutes to perform...
Do tbarb's test; also, with the carb cold take the air cleaner off, blip the throttle by hand and make sure the choke completely closes...if so, then hold the choke plate open with one hand, blip the throttle again SHARPLY and look for a twin sprays of gas from the primary nozzles in the carb throat. If these checks do not work (and tbarb's test does) you have fuel issues for sure.
The above tests should take all of 10 minutes to perform...