71 won't start
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Joined: Feb 2004
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From: MAYWOOD MO
71 won't start
My vette is a 1971 base 350 4 speed coupe. The drive train is original except for the air cleaner and missing ignition shielding. I purchased the car in september and drove it alot last fall until the weather got bad. Now when I turn the ignition the car tries to start. It will rev up to approx 2500rpm and then die. I have had the carburator apart. I replaced the points, condensor, and coil, and yesterday I replaced the ignition switch. So far nothing has worked. I am getting tired of throwing new parts at the car with no results. Does anybody have any ideas? HELP!
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From: MAYWOOD MO
Re: 71 won't start (ettev)
Fuel was my first thought too. The fuel filter in the carb looks like new, and when cranking the engine with the fuel line disconnected, it pumps a steady volume of fuel. When I took the carb apart there was plenty of fuel in the bowl. That is why turned my attention to electrical. It seems like the engine will run when the key is in the "start" position, but dies when in the "run" position.
Drifting
Joined: Nov 2003
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From: Northern NJ
St. Jude Donor '04 & '05
Re: 71 won't start (nelson71)
Welcome to the forum. :yesnod:
If it was a chrysler, I'd say it's a open ballest resistor. Saw that many times with these cars. Perhaps a bad ignition switch??
If not that then I'll defer to those with with more knowledge on this topic than I.
Good Luck!
:seeya
[Modified by ACECO, 1:11 PM 2/13/2004]
If it was a chrysler, I'd say it's a open ballest resistor. Saw that many times with these cars. Perhaps a bad ignition switch??
If not that then I'll defer to those with with more knowledge on this topic than I.
Good Luck!
:seeya
[Modified by ACECO, 1:11 PM 2/13/2004]
Melting Slicks
Joined: Oct 2002
Posts: 2,865
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From: I may be getting old but I refuse to grow up
Re: 71 won't start (nelson71)
Get a wiring diagram, there is a ballast resistor in the start circuit (some years used a resistor others a calibrated resitance wire) I'm not sure what year it changed. my 73 & 74 have the resitance wire.
Steve :steering:
Steve :steering:
Racer
Joined: Jul 2001
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From: Jasper, GA
Re: 71 won't start (stpman)
sounds to me like more of a fuel pump problem... they are relatively cheap... I would look at fuel supply before i would think electrical. Here is what to do... once you have started the car... , when it dies, do not crank it anymore. take off the air cleaner, pump the throttle a few times... is there gas pumping into the air horn on the carb?? If not, you have a fuel issue. I would think that either your fuel pump is going bad.. or the fuel bowl float in the carburetor is sticking. Look at fuel supply first. .. if it was electrical.. it would most likely not start!
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From: Denver Colorado
Re: 71 won't start (nelson71)
If the engine starts, then dies the instant you release the ignition switch, you need to look at the resistance wire that provides voltage to the distributor. While cranking, you get a full 12 volts to the distributor from the starter solenoid. Then when you stop cranking, you are supposed to get about 8 volts to the distributor from the resistance wire (ballast resistor). You need to start there, with the key on, do you have 8 to 9 volts at the distributor?
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Joined: Feb 2004
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From: MAYWOOD MO
Re: 71 won't start (Garrett1972)
Wow thanks for all of the good advice. If the resistor wire does prove to be the problem is that something that can be replaced individually, or am I looking at replacing the entire engine harness?
:chevy
:chevy
Le Mans Master
Joined: Sep 2003
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From: eastern NC
Re: 71 won't start (nelson71)
You stated that you had replaced the ignition switch. What exactly did you replace?
Did you replace the ignition switch that is on top of the column under the dash or the key switch below the steering wheel? What you described sounds like your ignition switch (the one under the dash) is malfunctioning.
These switches tend to separate a little on older Corvettes (most Chevrolets of this era use a similar switch) and when they do what you describe can happen. (It will start but shut off as soon as you release the key.)
You can remove it (the harness plugs into it and two screws hold it to the top of the column along with a rod from the key switch) and sometimes take it apart, clean it, relube it and put it back together. It is just clamped together and the clamps sometimes let go so it separates. If you can't repair yours, they are not too expensive and you can replace it with a new one.
GUSTO
Did you replace the ignition switch that is on top of the column under the dash or the key switch below the steering wheel? What you described sounds like your ignition switch (the one under the dash) is malfunctioning.
These switches tend to separate a little on older Corvettes (most Chevrolets of this era use a similar switch) and when they do what you describe can happen. (It will start but shut off as soon as you release the key.)
You can remove it (the harness plugs into it and two screws hold it to the top of the column along with a rod from the key switch) and sometimes take it apart, clean it, relube it and put it back together. It is just clamped together and the clamps sometimes let go so it separates. If you can't repair yours, they are not too expensive and you can replace it with a new one.
GUSTO
Racer
Joined: Dec 2003
Posts: 275
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From: NY
Re: 71 won't start (nelson71)
Here's a pagan trick... Hot wire the car. Place an allagator clip jumper between the the + of the battery to the + of the coil. Start it . If it runs fine then you have an ignition/start switch problem. If this has no effect then it's most likly fuel related. Happy hunting : BTW we are not talking acceleration after start?? Maybe accel pump clogged. Will it idle then not rev?
[Modified by sjr1971, 12:28 AM 2/14/2004]
[Modified by sjr1971, 12:28 AM 2/14/2004]
Le Mans Master
Joined: Sep 2003
Posts: 8,812
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From: eastern NC
Re: 71 won't start (nelson71)
Concur with sjr1971's trick.
If the car runs and idles fine you still have an ignition switch problem. In that case you can try adjusting the switch on the column by losening the screws and sliding it along the top of the column. I recommend sliding it toward the steering wheel first.
You can also remove it from the top of the column, reconnect the harness and manipulate the switch manually. If this works then it's an adjustment issue or there is a problem with the rod from the key switch.
It might be worth a try.
Good luck.
GUSTO
[Modified by GUSTO14, 12:54 AM 2/14/2004]
If the car runs and idles fine you still have an ignition switch problem. In that case you can try adjusting the switch on the column by losening the screws and sliding it along the top of the column. I recommend sliding it toward the steering wheel first.
You can also remove it from the top of the column, reconnect the harness and manipulate the switch manually. If this works then it's an adjustment issue or there is a problem with the rod from the key switch.
It might be worth a try.
Good luck.
GUSTO
[Modified by GUSTO14, 12:54 AM 2/14/2004]
Burning Brakes
Joined: Jul 2001
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From: Foxfield, Co
Re: 71 won't start (nelson71)
It seems like the engine will run when the key is in the "start" position, but dies when in the "run" position.
Greg.
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From: MAYWOOD MO
Re: 71 won't start (greg454)
Tonight was the first opprtunity I have had to work on the vette. I tried the jumper wire which allows the car to start and run! :thumbs:
Thanks to everyone for the good advice. What I need know now is does my 1971 350 with standard ignition have a ballast resistor or does it have a calibrated resistance wire like stpman suggested? None of my parts catalogs list a ballast resistor for a 71.
I am trying to get all of the bugs worked out now so I will be ready for POWER TOUR in June.
:steering:
Thanks to everyone for the good advice. What I need know now is does my 1971 350 with standard ignition have a ballast resistor or does it have a calibrated resistance wire like stpman suggested? None of my parts catalogs list a ballast resistor for a 71.
I am trying to get all of the bugs worked out now so I will be ready for POWER TOUR in June.
:steering:
Racer
Joined: Apr 2001
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From: Shoreline WA
Re: 71 won't start (nelson71)
According to Page 1 of the Sun Electric Technical Info on the 1971 corvette registry site, their is a 1.8 ohm calibrated resistor wire.
Here is the link to the information:
http://www.71corvette.com/sun.html
Mike
