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Yeah when I was doing mine and it told me the bypass the pink wire which I didn't want to do. So I started doing some research and someone on the forum here mentioned the relay so I found it and it was very simple to wire up.

73 Grande H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

 

- Jason

 

 

082-hot-rod-power-tour-2017-1970-1970s.jpg

 

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First, did you check for spark? I ask so I know if we are chasing an ignition problem or a timing problem.

 

If you did check for a spark and there was none, make sure the cap and rotor is good condition, and clean and dry. Any moisture or oil inside the cap can prevent it from starting. If all that is good, open and close the points with the key on, you are looking for an arc as the point s open and close. If no arc, check the resistance on the coil. With the test leads across the + and - terminals, primary resistance should be around .5 to 2 ohms, check the secondary resistance with the + lead to the + side of coil and other lead to the coil output, resistance should be around 6K to 15K ohms. If the coil resistance is good check the condenser, disconnect the condenser wire and hook the condenser lead to battery voltage for a few seconds and then check the condenser for voltage, it should show voltage and slowly bleed down. If no voltage then it's probably shorted.

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There is spark on initial cranking but not any more until you stop cranking. I will check the coil and condenser and get back to you.

 

Sent from my LGLS990 using Tapatalk

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First, did you check for spark? I ask so I know if we are chasing an ignition problem or a timing problem.

 

If you did check for a spark and there was none, make sure the cap and rotor is good condition, and clean and dry. Any moisture or oil inside the cap can prevent it from starting. If all that is good, open and close the points with the key on, you are looking for an arc as the point s open and close. If no arc, check the resistance on the coil. With the test leads across the + and - terminals, primary resistance should be around .5 to 2 ohms, check the secondary resistance with the + lead to the + side of coil and other lead to the coil output, resistance should be around 6K to 15K ohms. If the coil resistance is good check the condenser, disconnect the condenser wire and hook the condenser lead to battery voltage for a few seconds and then check the condenser for voltage, it should show voltage and slowly bleed down. If no voltage then it's probably shorted.

I tested the coil. Primary is 1.8 secondary is 9.75

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There is spark on initial cranking but not any more until you stop cranking. I will check the coil and condenser and get back to you.

 

Sent from my LGLS990 using Tapatalk

 

Ok, grab a spare piece of wire. Run it from the positive battery post to the positive on the coil. Try starting the engine. If it keeps running there is a problem somewhere in the wiring or you are running the wrong coil. Be aware that the engine will NOT stop running until you remove the spare piece of wire. Even turning the key off will not work.

 

The coil has two positive connections going to it. One includes a resistor wire and it engergized when the key in on (and cranking). There is a factory resistor wire that drops the voltage. There are reasons for this but lets keep this post short.

 

 

The second connectioncomes from the starter solenoid. When the solenoid is activated there is a small post that is energized in addition to the large wire that goes to the starter. This provides more voltage during cranking to the coil.

 

Let us know if this helps and then we can work out the rest of the problem. (If this doesn't help then it elminiates a few things as well)

'Mike'

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

 

Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]

 

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spark when cranking that goes away when you quit cranking is a sign that there is a problem in the wiring.

 

When cranking the coil gets a full 12v boost from the starter relay/solenoid. If your spark stops after that trace the coil wire back through the harness and you will find a connector- It may simply not be plugged in completely.

http://www.7173mustangs.com/gallery/1_01_07_15_8_53_18.png

 

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!

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Yeah when I was doing mine and it told me the bypass the pink wire which I didn't want to do. So I started doing some research and someone on the forum here mentioned the relay so I found it and it was very simple to wire up.

 

Yeah, I wish I'd known about it back in 2012 when the Pertronix was installed by the engine shop. Took a lot of back breaking work to do it under the dash. The relay would have save all that agro.

Geoff.

 I learn something new every day!

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If you have spark when cranking it, it should sound like it wants to start. If that's the case, do like Will said and run a hot wire from the battery to the coil, crank it, it should start, if so, like he said, you will have to remove the hot wire to turn it off. Then you will know that you have a wire or ignition switch issue, or possibly the relay.

 

If you have spark and it doesn't start after trying the hot wire, then you may have the distributor in a tooth off.

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Technically there is no such thing as a distributor tooth off. The only time you would need to change the relationship is if the ability to turn the distributor housing keeps you from getting it to the inital timing you want. This is usually caused by the vacuum advance being blocked from further movement by an accessory or radiator hose.

'Mike'

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

 

Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]

 

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Maybe your not holding your mouth just right

http://www.7173mustangs.com/gallery/1_01_07_15_8_53_18.png

 

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!

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I had this problem last summer, car ran great shut it off and would kind of start but not really. I took it to an old garage down the street, they said carb rebuild. $100 later it wasnt that. I had to tow it a couple times $200. Got it to my shop looked at the timing for days, sometimes it would sort of start but would not keep running. Checked all of the above, spark, timing, TDC, spun the dizzy everything. 73, 351C.

 

Finally for no good reason I took off the points and condenser and put on the old pertronix which I removed a year earlier then cranked it and BAM, it started right up, instantly, and still runs great. It was a $ 1.95 condenser, although it tested fine. A long time ago we did points and condenser every year whether the car needed it or not. Guess my year was up.

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After a new coil it will run for about 5 minutes and then struggle and die. Would the cause still be points and condensor?

 

Sent from my LGLS990 using Tapatalk

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Did you get an external resistor coil? What voltage do you have at the coil while the car is running for those 5 minutes.

 

Connect a dwell meter and watch what happens when the car starts to sputter and die.

'Mike'

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

 

Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]

 

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The condenser may be breaking down under load. The purpose of the condenser (it is just a capacitor) is to minimize arcing when the points open. It will run without it, just not well and the points won't last long without it. I would disconnect it and see if it will run, if it does, you'll know it is the condenser.

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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Part of my agony was the garage replaced my coil with an external resistor coil and added a resistor, which didn't make any difference. The garage also replaced the plugs even though they had less then 500 miles on them, the coil had about 700 before he replaced it. They went from coil, to plugs to rebuild carb, then I took it to my garage. It was my condenser that fixed it.

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Part of my agony was the garage replaced my coil with an external resistor coil and added a resistor, which didn't make any difference. The garage also replaced the plugs even though they had less then 500 miles on them, the coil had about 700 before he replaced it. They went from coil, to plugs to rebuild carb, then I took it to my garage. It was my condenser that fixed it.

I feel for ya. This is one of the reasons I try to avoid letting other folks work on my car. Part of the problem is modern mechanics just don't know how to work on the old stuff. There is a speed shop in town that I am going to one day take my car to. They have a dyno and folks who know how to tune older cars. You can get them to set your car up pretty good.

'Mike'

73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

 

Pics of modifications included in: [button=http://www.7173mustangs.com/thread-1973-convertible--3335]My Garage[/button]

 

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