Pontiac GTO Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter #1
Started my 67 after many years yesterday and it cranked over very easy then when the engine warmed up it was very difficult to start.Battery is brand new and super duty 1000 amps, Thanks for any help
 

·
64-67 Expert
Joined
·
8,569 Posts
Possible: high resistance in starter windings, high resistance in battery cables, overly advanced timing due to sticking centrifugal weights caused by gummed up distributor shaft. (Very common on cars that have sat awhile!)
 

·
Registered
Joined
·
4,389 Posts
Started my 67 after many years yesterday and it cranked over very easy then when the engine warmed up it was very difficult to start.Battery is brand new and super duty 1000 amps, Thanks for any help
Carb might be dried out from setting so long and needs a good rebuild - new gaskets, accelerator pump, needle & seat. You could have gas dripping into the intake and this would also cause a hard start problem - kinda like flooding the engine.
 

·
Registered
Joined
·
144 Posts
Heat soaking of starter........a known Pontiac problem.....my 78 TA does this.......just let it cool down for 20-30 minutes....then it starts fine again.
 

·
Registered
Joined
·
42 Posts
Discussion Starter #5
could this be a problem due to the timing be to far advanced ? if so which way would I turn the distributor to retard it ? Thanks
 

·
Registered
Joined
·
1,022 Posts
Pontiac distributors turn CCW........you turn against rotation to advance and with rotation to retard.....

But I doubt it is timing as timing does not change between a cold and hot start,...unless a condition like GTO guy said with sticking weights.

Rather your car started fine cold,....that means the choke and fast idle cam were able to give it a rich enough mixture so it fired right up...

But all those systems are not supposed to be in play on a hot start,.....so Like PJ said a gummed up carb, idle mixture set a bit too lean....

Also make sure the choke and fast idle cam release, because if they are stuck....the mixture will be too rich when hot and the car will not start because it is flooded,. Will smoke and idle rough if they stay engaged..

Could also be electrical resistance that does not occur until hot....

To begin with use some carb cleaner on that carb, for a quick clean, You still should rebuild it after 10 years. Look under the distributor cap and check weights and springs, a spring could be off,...and get fresh gasoline.

Leave that timing alone for the moment, it started,....investigate some other places or you will get hung up,....you can check it with a timing light.....to see where it is without moving it.>:):nerd:0:)
 

·
64-67 Expert
Joined
·
8,569 Posts
You can rule out the sticking distributor weights in 2 minutes next time it acts up. Simply pull the dist cap and see if you can manually turn the rotor. If you can, it was stuck in the mechanical position due to a gummed up distributor shaft. Very common. If this is NOT the issue, at least you've eliminated it. From your description, it is a slow cranking when hot issue, correct? NOT a crank and crank and crank, but no start issue?
 

·
Registered
Joined
·
42 Posts
Discussion Starter #8
You can rule out the sticking distributor weights in 2 minutes next time it acts up. Simply pull the dist cap and see if you can manually turn the rotor. If you can, it was stuck in the mechanical position due to a gummed up distributor shaft. Very common. If this is NOT the issue, at least you've eliminated it. From your description, it is a slow cranking when hot issue, correct? NOT a crank and crank and crank, but no start issue?
Nope not a starting issue, Spins like hell when cold but when I turn it off and immediately try to re start it when hot it bogs down, almost like there is to much compression to let the pistons spin (I know this is not the case but trying to explain what it does)
 

·
Registered
Joined
·
51 Posts
Do you have headers on the car? I experienced this on my 70 skylark after I installed headers. The starter got too hot and acted like the compression was super high. Buy a heat wrap and wrap the starter. Should take care of the problem.
 

·
Registered
Joined
·
42 Posts
Discussion Starter #12
You know maybe it is the choke. Here is a picture of mine, is there supposed to be something that goes or connects where the rubber tube is. This is how it came back from the carb shop a number of years ago.
 

Attachments

·
64-67 Expert
Joined
·
8,569 Posts
Yep. Your heat tube is missing. Supposed to be a tube from the intake manifold to the choke to heat up the choke spring and open the choke. The vendors should have them. A five minute fix.
 

·
Registered
Joined
·
18 Posts
I cured this same problem with my SBC in my 75 Vega. It was the contacts in the solenoid; took it apart and cleaned/filed the mating surfaces. At the same time I added an external relay that took the load to start the solenoid off the key switch; ie now when the key is turned, the relay activates and it activates the solenoid.

Never an issue after that...
 

·
Registered
Joined
·
1,022 Posts
Yes and ditch that clear plastic tube if hooked to the hot exhaust crossover it will melt. Use rubber.

Another track is to add an electric choke very easy set up 1 wire to key on power....

Either way with no choke, and you have no choke set up like this the car will be a hard start cold....
 
1 - 16 of 16 Posts
Top