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Old 20th-April-2017, 11:21 PM   #1141
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Quote:
Originally Posted by romancommander View Post
My question regarding the alternator wire size, has to do with recharging and overall system voltage.

Stock, Gm connected the battery and alternator through a 10ga wire going to the starter. While easy for manufacturing, it is not the best for a fuel injected electrical system. Compounding the problem is the fact that your battery is 20 feet away from it. I asked because if you are running the stock 10 ga wire (hell or even 4 ga) you'll have 15% or more voltage drop from the alternator to the battery. The alternator may output 14 volts, but your battery may only ever charge to 12V, and remember dropping system voltage is your main problem here. It is all related. The bigger the wire from the alternator to the battery, the less voltage drop.

.
I definitely am not using stock wiring. All was renewed. The wire size is 2 Gauge. When car is on, The highest I have seen is 14.5v (when cold). Average is 14.1v. When electric fan is on its 13.8v

Quote:
Originally Posted by romancommander View Post
With the car off, what is your voltage reading at the battery?.
I have not used the car in almost a week and I do have an alarm light that stays on all the time when the car alarm is active. I just checked and its currently 12.85V at the battery. At the front posts its 12.8V.


Quote:
Originally Posted by EdyJun View Post
I have 2 questions, isn't the ECU supposed to be connected to the battery directly? (where are you installing the ECU?)
Yes. The ECU is connected directly to the battery posts in front. There are two connections.

Quote:
Originally Posted by EdyJun View Post
And instead of spending the money on the cap, would it make sense to upgrade the wires from the batt in the trunk to the front instead? (that would fix a lot of the issues)
Not practical. And though I would like to have 12V to the ECU while cranking, Its not a big enough reason to justify redoing the wiring from 1/0 to 2/0.

Quote:
Originally Posted by EdyJun View Post
BTW isn't the vol 13.0-13.2V for YELLOWTOPs
Correct. When I placed battery in the car it was at 13.1 Volts. The Redtops fully charged are at 12.8v
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Old 20th-April-2017, 11:35 PM   #1142
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When the car is running, you are reading alternator voltage at the point where your gauge is hooked in, which your numbers point to a healthy alternator. Voltage drop increases as current demand increases (which is what you are seeing when your voltage dips below 12v).
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Old 20th-April-2017, 11:47 PM   #1143
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Since the Ecu draws so little, you maybe money ahead with a separate small 12v Agm. Something from a power wheels would work, like an 8 amp hour. Then just connect it with a small "run hot" not "start hot" lead to charge it. I don't think you'd even need a battery isolator as it would be separate from the starting circuit. I buy these type of batteries from my local Batteries Plus.

https://www.walmart.com/ip/Universal...&wl13=&veh=sem
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Old 21st-April-2017, 10:58 AM   #1144
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From my understanding of capacitors, they lose voltage (discharge) over time. There are times when I have the car sitting for a couple days and if the cap is a temporary source of power, then that would be bad.
So I asked about it...

Quote:
Originally Posted by romancommander
So there are two factors that cause a capacitor to discharge. 1. Internal leakage (known as desulfating in a battery)
2. External Current draw, (memory wires, alarm, etc)

If you buy a good cap, then it should have minimal internal leakage and stay charged a long time, but it will also be connected to the battery so it would at minimum maintain the batteries level of charge. I would not try to use a cap that wasn't connect directly to the battery, I don't think it would work.
.
So I came up with this Concept.



The Capacitor would receive power from the battery always when the car is off via a NC relay. This would keep the capacitor charged at all times. When I turn on the car, the NC relay would open and cut power from the battery to the capacitor. This would prevent the capacitor from discharging by starting the car. The Capacitor would then slowly power up the ECU giving it 12v.
When car starts and Alternator starts to charge (over 13v), the capacitor would once again receive battery power via the battery combiner/isolator.

Starting the car would take seconds so it is my understanding that the capacitor would be able to power the ECU for a little while (while the car is cranking) before being completely drained because it would only be consuming less than 10 amps. I chose a 2 Farad Capacitor which in my understanding would be equivalent to 166 amps of storage power.
There are 2 connections for the ECU. One in which is specifically for the ECU to turn on. The other for all the sensors of the ECU to get power. This connection would be connected to the battery. The ECU connection goes to the Capacitor.
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Old 21st-April-2017, 12:18 PM   #1145
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Quote:
Originally Posted by Tarantula View Post
From my understanding of capacitors, they lose voltage (discharge) over time. There are times when I have the car sitting for a couple days and if the cap is a temporary source of power, then that would be bad.
So I asked about it...



So I came up with this Concept.



The Capacitor would receive power from the battery always when the car is off via a NC relay. This would keep the capacitor charged at all times. When I turn on the car, the NC relay would open and cut power from the battery to the capacitor. This would prevent the capacitor from discharging by starting the car. The Capacitor would then slowly power up the ECU giving it 12v.
When car starts and Alternator starts to charge (over 13v), the capacitor would once again receive battery power via the battery combiner/isolator.

Starting the car would take seconds so it is my understanding that the capacitor would be able to power the ECU for a little while (while the car is cranking) before being completely drained because it would only be consuming less than 10 amps. I chose a 2 Farad Capacitor which in my understanding would be equivalent to 166 amps of storage power.
There are 2 connections for the ECU. One in which is specifically for the ECU to turn on. The other for all the sensors of the ECU to get power. This connection would be connected to the battery. The ECU connection goes to the Capacitor.

A couple things.

1. I originally suggested a cap to attenuate your voltage drop when installed in the engine bay and help your starting, to alleviate having to change out your 1/0. I still think this the best idea because it fixes a systemic problem, but I understand the engine compartment lack of space problem, and the fact that its only an issue during cranking. It was merely a thought I had, there are tons of wasy to skin this cat.

2. The scenario you are outlining would probably work, but is a little expensive and a little complicated, and technically not the best use of a cap.

Since the ECU draws so little, a simpler system would be to go with what you originally intended, involve a small 8ah-ish battery mounted in the trunk, relatively large wires going to the ecu to negate voltage drop (12ga? 10ga?) and instead of battery combiners or isolators a simple charging relay/trickle charger that only energized when in the "run" position. It would be a completely separate system, cheap, easy, small.
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Last edited by romancommander; 21st-April-2017 at 12:20 PM.
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Old 11th-May-2017, 10:09 PM   #1146
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LOVE this thread!

Quote:
Originally Posted by Tarantula View Post
Man, this thread is more like I'm talking to myself lol...
I bought a '74 Custom Hatchback last year and am finally get it completed this month. I am so excited to see your work & can't wait to finish reading your posts to see the outcome!
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Old 15th-June-2017, 03:29 AM   #1147
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Ignition Control

When I first installed system, I did this...

Quote:
Originally Posted by Tarantula View Post
For the wiring harness, I re organized some of the wires to correspond to the location I will need it in my engine bay. I also decided to cut off/modify two input harness plugs.
The first one I cut off completely was the Ignition control harness. To use this the manual states that I need a specific EFI distributor. Currently I do not want to get into ignition control so I cut it in a way that if I wanted to reconnect it, I could do so in the future. Its just two wires.

The second one is the tach input. I felt that I did not need a harness or a connector for just a one wire connection to the negative side of the coil. My Dakota Digital instrument cluster has been doing great connected to the coil, so I am confident that the EFI ECU will do so as well.
Changed my mind....

Ok so as I used the car with the new EFI system, I noticed that I was having problems with the idle. Occasionally it would idle erratically or it would hunt up and down then shut off. It was totally random. Never had problems while driving. Only at idle.

I called up tech support and they told me that there is probably noise from the coil. Or some other interference that is preventing the ECU from receiving a clean tach signal. And without a tach signal the computer wont know what to do for its calculations.

So I decided to bite the bullet and order the ignition control system. It was the only sure fire way of having the cleanest tach signal.



Though a bit expensive, I was happy in deciding to get it. I can see the benefits to having ignition control. Here's the unit setup. Its basically a MSD Pro billet distributor.



The cap and rotor setup I have in the car is a female HEi setup. This new distributor has male HEi. So this meant more stuff to buy/upgrade. So I wanted wires that had great EMI suppression. So I opted to get Taylor Wires. The resistance was pretty low at 50 ohms of resistance per foot. I decided on the universal set so I could make each wire a custom length.



With new wires, I need a new coil. So I opted for a red one...MSD Blaster 2.



So now for the install. I first made sure the engine was 12 Degrees BTDC and pointing to the Number 1 spark wire. I used a wrench to turn the engine.



Then I pulled my old distributor. I did upgrade the ignition just a couple months ago.



A look at the two side by side.



After pulling it out I proceeded to reattach the wires I cut off. I soldered each wire very carefully to ensure a perfect connection. Here the wires before I reattached them. I took my time.



After the wires were all done, I proceeded to drop in the distributor. I had to realign the oil pump drive shaft to ensure I get the rotor exactly where I wanted #1 to be. I prefer it to be on the passenger side around 7 o'clock position.



Distributor in.



Since all the wires are custom, I also cut the coil wire to my personal preference length.



For the new wires, I added some heat protection sleeves. Want to protect my investment.



Here's what my old wires looked like. This is 17K miles on top of the headers.



Now I have to say this unit made a big improvement to the way the system operates. The idle was now much steadier and I don't have random mishaps with the idle. Does not turn off randomly.
With my experience I will say that if you are going to get an EFI system, and they offer ignition control, GET IT! I don't know why they just don't sell it as a full kit. Before deciding on buying the Ignition Control, I read as much as I could on problems with idle with EFI setups. And many have stated the same....Once they got Ignition control, things ran a lot smoother and problems went away.

So I played with the settings and man, the control I have to change things on the fly is so convenient. I could even make changes while driving if I wanted to. Here's a screenshot to show how monitor things.



So after many combos, I landed on the following.

Initial is at 22 Degrees. Starts up easily.
Ignition advance curve starts at 1000 rpms and all in at 1900 rpms
Max All in advance 36 Degrees (WOT). I have tried up to 38 and feels great. But decided to stick with 36 for safety.
Vacuum advance is 10 degrees.

So why did I decide on this timing curve? Its based around my transmission and how I drive the car.
On the freeway, 70 MPH is 1940 rpms. This is why all in stops at 1900. And around town, I can be at 1000 rpms around 40 mph. So that's why the curve starts at 1000. With this curve, the throttle response is snappy and crisp. And for the first time, Overdrive around town has some torque and the engine does not feel like its lugging at low rpms (overdrive brings rpms down to 900 initially).

My A/F ratio also reflects these timing numbers.
Idle is 13.4 (up to 1400 rpms) So even though timing starts climbing early, The fuel mixture is on the rich side to keep things safe.

Cruise 14.8 (1400 rpms and up) By the time I'm cruising, the lean mixture gets a little help from the advance timing for a better burn. Leaner mixtures take longer to burn so more advance helps get things started.

The only thing I wish for is more advance for the vacuum. It caps off at 10 degrees. And on average it does not give you the full 10. It usually gives me 7 degrees. So at 22 degrees at idle, 19Hg of vacuum brings it up to around 29 degrees (it jumps around between 26-29). I'm currently speaking with tech regarding getting the 10 degree cap for vacuum lifted to 18-20 degrees so that the user can have more options.
During cruise I get only about 40-42 degrees of timing (cruise vacuum is around 15Hg). I would prefer a bit more .

Will continue to monitor and I may tweak things. This is what I was missing from my EFI setup. And there's no going back now.

Oh and now I can connect using my smartphone! Even more convenient!
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Last edited by Tarantula; 15th-June-2017 at 03:31 AM.
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Old 15th-June-2017, 06:49 PM   #1148
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Glad to see you got it working. Cool. keep it up!
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Old 19th-June-2017, 10:42 AM   #1149
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Glad to see you got it working. Cool. keep it up!
Thank you. Timing control is so convenient.
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