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73 454 wont start (1/10)
 5/25/19 7:10am
Geoff
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Woodbury, CT - USA

Vette(s):
1973 corvette 454 big block 4 speed


Joined: 7/12/2018
Posts: 10

I am getting fuel and spark. I pulled the carb off and checked it out and everything seems fine. I took the HEI cap off and checked the wires and everything seems fine. I took a spark plug out and its sparking. It just cranks over and nothing. Its the second time this happened. Last weekend and then yesterday. The car was a barn find that sat in a garage for thirty years and I have been working on for 3 years now. Most everything that was not working has been fixed, I think. Thanks in advance for helping.

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Re: 73 454 wont start (2/10)
 5/26/19 1:57am
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 550

HEI is a mod on a 73 as it didn't come out until the 74 or 75 model,  can't remember which. Spark on an open plug doesn't mean it will spark under compression. When you set the choke, does the accelerator pump squirt gas? If not then probably not getting any spark. See if a timing lite will flash.



|UPDATED|5/25/2019 10:57:13 PM (AZT)|/UPDATED|


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1973 L-82 4 spd

Re: 73 454 wont start (3/10)
 5/26/19 7:00am
Geoff
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Woodbury, CT - USA

Vette(s):
1973 corvette 454 big block 4 speed


Joined: 7/12/2018
Posts: 10

Thanks for helping. I added the HEI dist. because the car came with a dual point dist. I checked the carb and its squirting fuel. I took out all the plugs and they seamed a little dark and fouled from flooding. I'm going to replace the plugs and hook up a timing light to check for spark. I never thought of doing it that way before. Very Smart. Thanks for the tip.



|UPDATED|5/26/2019 4:00:38 AM (AZT)|/UPDATED|
Re: 73 454 wont start (4/10)
 5/26/19 9:18am
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19627

A weak spark with the plug out of the hole doesn't mean it will fire under compression, as was mentioned. If it doesn't have a fat, solid blue spark across the electrode, the spark is weak. With the HEI system, I would be looking at a failing coil or ignition module, and possibly a burnt rotor.

If you take the rotor off, flip it over, and look for what could be called lightning bolts on the underside. (Easy to see with light colored rotors, but hard with black ones.) The lightning bolts are from the ignition spark trying to find ground when the plugs/wires are not up to snuff. The closest ground for the spark inside the dist is the two screws that hold the rotor to the shaft...so the spark tries to get to the screws, producing the lightning bolt pattern on the rotor. This indicates fouled/faulty plugs, and/or faulty plug wires. 

If you look at the coil on top of the dist cap, if you see the metal cage has turned blue in some areas, that indicates the coil has been overheated, which happens when all of the plugs aren't firing properly. This heat is what will fry the ignition module. Best bet when you have any one of these issues is to replace ALL of these components at the same time...cap, coil, rotor, module, plugs and wires. Another tip on HEI systems...don't buy the cheapest cap/rotor set the parts place has just to save a few pennies. The type of plastic used will make a huge difference in the quality of spark sent to the plugs, and some of these lower cost parts are questionable at best.. Get AC/Delco stuff for the cap/rotor...your iggy module and coil will thank you later. 👍



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Joel Adams
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Re: 73 454 wont start (5/10)
 5/26/19 12:32pm
Geoff
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Woodbury, CT - USA

Vette(s):
1973 corvette 454 big block 4 speed


Joined: 7/12/2018
Posts: 10

wow that's a lot of stuff to sort threw. I feel like you are an expert on this. I will look at everything that you suggested one by one. Thank you. 

Re: 73 454 wont start (6/10)
 5/27/19 11:04am
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19627

I'm no "expert"....but I play one on TV.....lol

I can email you test procedures for the HEI system if you want. 👍



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Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Re: 73 454 wont start (7/10)
 5/27/19 12:28pm
Geoff
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Woodbury, CT - USA

Vette(s):
1973 corvette 454 big block 4 speed


Joined: 7/12/2018
Posts: 10

Joel, That would be great

quinnfloors@sbcglobal.net



|UPDATED|5/27/2019 9:28:29 AM (AZT)|/UPDATED|
Re: 73 454 wont start (8/10)
 5/27/19 7:19pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19627

"You've got Mail!!"



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Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Re: 73 454 wont start (9/10)
 6/2/19 4:25pm
Geoff
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Woodbury, CT - USA

Vette(s):
1973 corvette 454 big block 4 speed


Joined: 7/12/2018
Posts: 10

Thanks everybody for solving my problem with my car. You guys nailed it. The problem was the distributor and or related parts. I bought a whole new dist and coil and it started right up. I think its a better looking set up.Thankfully I will be going to the car show this coming Sunday. Thanks again !

Re: 73 454 wont start (10/10)
 6/2/19 9:32pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19627

👍 Good to hear! 



______________
Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"