Stalling issue w/ 1973 454 4spd
Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
Stalling issue w/ 1973 454 4spd
Wondering if anyone has experienced their C3 periodically stalling. On occassion my vette will stall out then restart after a couple of minutes. Sometimes it happens in my neighborhood and other times, I can drive 50 miles before stall.
Wondering if it may be the fuel filter or possibly something in the carb.
Any advise would be appreciated.
Wondering if it may be the fuel filter or possibly something in the carb.
Any advise would be appreciated.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
I'd check the simple stuff first= fuel filter would top my list. Right after that, I'd look at the whole list of symptoms. How does it stall? Like it's running out of gas or like you shut the key off? If it acts like it's running out of gas, it won't do much for your problem to chase the ignition system.
Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
Hey Tim,
The car pretty much just dies and comes to a rolling stop. Power steering quits, etc. Once stopped, it will turn over (starter ok), but will not fire up for a couple of minutes. Like I said, sometimes it happens just a few hundred feet from the house and other times I can drive to work (30 miles) and back but will quit just a mile or so from the house.
I agree that swapping the fuel filter would be the easiest and cheapest start. Also recently, I had my Q-jet borred a bit and wondering if debris may be stuck in the system somewhere. Also I inspected the sending unit in the tank and it appears to be fairly new.
The car pretty much just dies and comes to a rolling stop. Power steering quits, etc. Once stopped, it will turn over (starter ok), but will not fire up for a couple of minutes. Like I said, sometimes it happens just a few hundred feet from the house and other times I can drive to work (30 miles) and back but will quit just a mile or so from the house.
I agree that swapping the fuel filter would be the easiest and cheapest start. Also recently, I had my Q-jet borred a bit and wondering if debris may be stuck in the system somewhere. Also I inspected the sending unit in the tank and it appears to be fairly new.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
When it quits, jump out and get under the hood. Pop the air cleaner and see if there's gas in the carb. Does it feel like it's surging as it quits? Or just falls down dead? 73 was still point ignition- might pay you to take close look at the primary lead from the coil to the distributor. they have been known to fail. And check the plate in the distributor the points mount to. Make sure it's solid. It pivots with the vacuum advance, but there's a snap ring that holds it in place.
Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
I have checked the primary lead in the past and seemed to be solid, plus the fact I recently installed new plug wires and coil. I will check the distributor plate today.
Also an unrelated question for you...my passenger door gapping is a bit off. I have taken it to a local guy who has a vette repair shop for evaluation. He is telling me that the front quarter needs to be re-mounted to even the gap. As a result, he is also saying it will have to be repainted as a result of the repair. Does this make sense? I'd hate to repaint as my vette currently has a 8K paint job.
Also an unrelated question for you...my passenger door gapping is a bit off. I have taken it to a local guy who has a vette repair shop for evaluation. He is telling me that the front quarter needs to be re-mounted to even the gap. As a result, he is also saying it will have to be repainted as a result of the repair. Does this make sense? I'd hate to repaint as my vette currently has a 8K paint job.
Instructor
Joined: Sep 2006
Posts: 175
Likes: 11
From: Omaha ne
Sounds an awful lot like vapor lock. We have had several cars lately that will do exactly as you describe and have found that running 10% ethanol fuel is the culprit. Ethanol has a lower boiling point than normal gasoline and therefore is prone to vapor locking on the older cars. The newer vehicles use a re circulative fuel system IE: the fuel is constantly moving. On older vehicles it sits in the fuel line above the intake in a hot engine compartment and the result is vapor lock. A somewhat quick way to check is to temporarily rig a see through filter near the carb. try not to disturb the line routing as it may impact your results. When cold it should be close to full. As it gets hot you can watch the level in the filter drop until it quits running.
Staying away from the etahnol blends has resolved the problem in every case
hope this helps
Tim
http://tandmautomotive-omaha.com/
Staying away from the etahnol blends has resolved the problem in every case
hope this helps
Tim
http://tandmautomotive-omaha.com/
Last edited by TJP440; Aug 2, 2009 at 03:16 PM.
Drifting
Joined: Mar 2006
Posts: 1,526
Likes: 2
From: Oak Ridge NC
Sounds an awful lot like vapor lock. We have had several cars lately that will do exactly as you describe and have found that running 10% ethanol fuel is the culprit. Ethanol has a lower boiling point than normal gasoline and therefore is prone to vapor locking on the older cars. The newer vehicles use a re circulative fuel system IE: the fuel is constantly moving. On older vehicles it sits in the fuel line above the intake in a hot engine compartment and the result is vapor lock. A somewhat quick way to check is to temporarily rig a see through filter near the carb. try not to disturb the line routing as it may impact your results. When cold it should be close to full. As it gets hot you can watch the level in the filter drop until it quits running.
Staying away from the etahnol blends has resolved the problem in every case
hope this helps
Tim
http://tandmautomotive-omaha.com/
Staying away from the etahnol blends has resolved the problem in every case
hope this helps
Tim
http://tandmautomotive-omaha.com/
Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
Thanks for the info Tim. Wondering if the car restarting within just a couple of minutes after stall would be consistant w/ vapor lock? Also would the vapor lock issue be fairly consistant...meaning would it always happen once the engine reaches temp, after the car is driven a set # of miles, etc? My issue has occured both in my neighborhood right after leaving the house, and also after driving for 50 miles....so fairly inconsistant.
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Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
I have only owned my Vette for approx. 5 years. It was completely rebuilt / restored from previous owner. I'm not sure where to look for the vapro return line to see if it's still in place. Could you give me an idea where to look? Does it come off of the carb or engine?
Drifting
Joined: Mar 2006
Posts: 1,526
Likes: 2
From: Oak Ridge NC
I have only owned my Vette for approx. 5 years. It was completely rebuilt / restored from previous owner. I'm not sure where to look for the vapro return line to see if it's still in place. Could you give me an idea where to look? Does it come off of the carb or engine?
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
I don't think that is actually a "vapor" return - it is a fuel return. Any fuel from the pump that is not needed by the carb is returned to the tank. The theory is that by constantly recirculating the fuel back to the tank it won't overheat and vaporize, causing vapor lock. Earlier C3s had the return line coming out of the filter that was mounted vertically in front of the right (passenger) side head. I'm not sure when they switched from that to the return from the fuel pump, but the operation is the same.
Pro
Joined: Feb 2002
Posts: 709
Likes: 10
From: Carlsbad CA
I had this problem on my 69 years agos. Thought it was vapor lock. Does it happen when the fuel tank is full? If not, next time tank is almost empty, take off cap an look at pick up sock. There may be debri in tank and when fuel level is low it gets sucked up on fuel pick up tube and shuts off fuel flow. On my car, a piece of old cork gasket for the cap had fallen in the tank. Since it was cork it would float and only cause a problem when fuel level was low.
Thread Starter
5th Gear
Joined: Aug 2009
Posts: 5
Likes: 0
From: Allen TX
My tank is original and doesn't look too bad. I have looked in the tank in the past (prior to this issue) and at a minimum the sending unit and assembly has been replaced. I will take another look to see if there may be some debris clogging the strainer.
Thx.
Thx.
Instructor
Joined: Sep 2006
Posts: 175
Likes: 11
From: Omaha ne
Thanks for the info Tim. Wondering if the car restarting within just a couple of minutes after stall would be consistent w/ vapor lock? Also would the vapor lock issue be fairly consistant...meaning would it always happen once the engine reaches temp, after the car is driven a set # of miles, etc? My issue has occurred both in my neighborhood right after leaving the house, and also after driving for 50 miles....so fairly inconsistent.
As far as the restart time it varies.
Again back to temperature. I will say the hotter it is the more likely you may see it
Another thought I just had was if possible, as soon as it stalls get the hood up, crank it and check for consistent spark. If you have consistent spark then it's more likely fuel related. Intermittent issues like this are always a challenge.
My best advice is to first try and figure out if there is a way to duplicate the issue.Then isolate it to electrical or fuel. if this is not doable shotgun the ignition system and wiring all the way from the distributor to the ignition switch. I have seen internally broken wires in the distributor cause this condition as well, so overlook nothing. IF all of that proves fruitless we're back to looking at the fuel system. Report back and we can go from there
Tim
http://tandmautomotive-omaha.com/
Last edited by TJP440; Aug 2, 2009 at 10:17 PM.
1st Gear
Joined: Mar 2012
Posts: 1
Likes: 0
From: Tulsa, Ok
My 1973 did exact same thing last couple weeks. It was the fuel pump. Symptoms were it loped, chugged, lose power and then die. Sit a couple minutes and it would start right back up and would run okay for maybe 2 minutes or two days thne do it again. Fuel pump was the problem but the way it acted led me to think vapor lock, tank sock, etc.,etc,, also. Fuel pump was only $55 bucks and I bet I spent 3 days trying to figure it out checking stuff.
Secondly, if you ask for help on the forum about an issue be kind enough when you fix it to post the fix so others hunting advice on a similiar problem have feedback would be really great. I came on here and searched and found several members psoted kind reponses whch I used to trouble shoot and repair this issue on my 73 that had been asked by aonther member earlier but no where did the person who sought the help bother posting back what he found to be the problem or say thanks to those who helped him out. So thanks to all who posted the possibilities which helped me figure it out.
Secondly, if you ask for help on the forum about an issue be kind enough when you fix it to post the fix so others hunting advice on a similiar problem have feedback would be really great. I came on here and searched and found several members psoted kind reponses whch I used to trouble shoot and repair this issue on my 73 that had been asked by aonther member earlier but no where did the person who sought the help bother posting back what he found to be the problem or say thanks to those who helped him out. So thanks to all who posted the possibilities which helped me figure it out.
Safety Car
Joined: Sep 2007
Posts: 4,458
Likes: 331
From: Indy Indiana
put your old coil back on and test it... if it is stalling in your neighborhood before it gets hot, it is not vapor lock. is your carb too hot to touch?
your new coil may be failing intermittantly.
your new coil may be failing intermittantly.
