70 up charging system upgrade question

[Mattax]

This is a hydraulic lifter engine - stock 318 ?

Is this the new 340 or the 273 with solid lifters?

I ask for two reasons.
Initial timing needs will be a bit different. On the 273 go with the stock specs, probly around 10-12* at 550 or 600 rpm. 340 will need more depending on cam & compression.
Other reason is solid lifters out of adjustment and the starting compression will be low. Not saying this is the problem, but my had this on his Saab (and other cars) due to some valve recession or similar wear. If it doesn't seal fully it doesn't run well. I also had that on my jeep when the valve springs failed - but there's no adjustment for that! Lots o fun (thats what happens when rusty pitted springs are cleaned and reused)

 

[4spdragtop]

Engine is a 273 adjustable valve train. I'm fairly confident this is not an engine timing issue. Although one of the pieces I replaced throughout this debacle was the distributor reluctor pickup. One wire had some missing insulation. Replaced with new one, gapped at 0.008". Made no difference.
Weird how the coil +ve was only 10.34 V but fired up. PROPERLY. I could see voltage meter fluctuating, but it fired up so quick I didnt see if it went any higher.
I gave the Black ACC wire from ing switch a coat of liquid tape as insulation is cracking. I also removed all female terminals from ign switch connector. I have a better style switch connector that will work better. Also gave me another chance to really clean female terminals.
I'll try to start again Monday, gives lots of time for liquid tape to dry.
I know have fusebox and headlight switch dangling lol. I know that the car deserves a new underdash harness and that had.moved to top of list. But something like that has to be planned out and budgeted for lol
Thanks again!

That seems about correct. It should run with lower voltage. It should start with battery voltage.
Remember, once its running, the alternator will be providing system power closer to 14 Volts. The ballast resistor will bring it down from that 14 for the coil positive. How much lower will vary with current flow and temperature. You're in the ballpark.

Charge the battery, get it running. System voltage should be around 14. Maybe a little less at idle and a little more at fast idle.
Then check initial timing, because right now that's seems like a possible reason it didn't want to start easily.

This is a hydraulic lifter engine - stock 318 ?

 

[4spdragtop]

So I had fingers crossed it would start, but no go. Cranks but still just cranks. I'm thinking poor connection but cant track it down. And I jumped from batt +ve to coil +ve and it did nothing. With 12v direct to cool shouldn't it crank/spark/fire up?

Tests with key on.
Batt static 12.05
Run side of ballast resistor 11.19
Start side of ballast resistor 8.02

Coil +ve and batt-ve 7.86v
Coil +ve and batt +ve 3.94 V. Shouldnt this be lower??
Coil -ve and batt -ve 2.09V
Coil -ve and batt +ve 9.78V
Do I need to jumper the starter relay(yellow) to something to hotwire? I thought 12v direct to coil +ve would have started it.
Thanks all

 

[Daves69]

Well gee Steve, on the bright side, I guess no one can just get in and drive it off on ya'!



Now you have nothing out of the high tension lead but it fires fine occasionally?

By chance, you don't happen to have one of these attached?
………..

How well is that ECU grounded? Are the female side of the connector terminals tight on the ECU posts? I never came across one but I've heard of folks having a bad "new" harness.
…….

Grounding possibilities....

 

[4spdragtop]

Lmao, true Dave. "High tension lead", you mean coil to cap? I haven't tried that recently. With everything hooked up, coil +ve to batt +ve I get 10.34V in start. I thought that MAYBE was low, so i figured give it a full 12V from batt +ve. Did nothing, whether key was off or in run. I thought maybe the relay needed to be jumped as well?
I'm pretty confident the ECU is grounded well. To test this I put meter on"continuity" and get "beeps" engine to Ecu, VR case to ECU, batt -ve to ecu. So I figure good grounds?
Although I'm not sure if I did batt -ve to ecu case. That would give me voltage drop I believe? Meter should read 0 for that correct?
I have another new ECU, as well as a used one(unknown comdition)from my 84 Dodge.
I'm pretty sure the harness is connecting tight but will check.
Thanks Dave.

Well gee Steve, on the bright side, I guess no one can just get in and drive it off on ya'!



Now you have nothing out of the high tension lead but it fires fine occasionally?

By chance, you don't happen to have one of these attached?
………..
View attachment 1715236597


How well is that ECU grounded? Are the female side of the connector terminals tight on the ECU posts? I never came across one but I've heard of folks having a bad "new" harness.
…….
View attachment 1715236596
Grounding possibilities....
View attachment 1715236598View attachment 1715236604

 

[Mattax]

Did I miss it? How do you know its not sparking?
My impression was that it fired up so you didn't bother getting a spark tester/

 

[4spdragtop]

Hi Matt, yes it did fire up normally a few days ago. Now cant get it to fire. Measured coil +ve to batt +ve and got 10.34v. I thought I would give it a full 12V direct from batt +ve to coil +ve and it doesn't even turn over.

Did I miss it? How do you know its not sparking?
My impression was that it fired up so you didn't bother getting a spark tester/

 

[Daves69]

Out of curiosity, what DVM are you using?

I'm pretty confident the ECU is grounded well. To test this I put meter on"continuity" and get "beeps" engine to Ecu, VR case to ECU, batt -ve to ecu.

It may be just fine as is.
I know paint, especially when new, is a hard thing for anyone to scrape off just for a solid ground. Coating on the ECU case can be an issue as well. A ring terminal and separate ground wire under one of the bolts might be an option to consider.

Although I'm not sure if I did batt -ve to ecu case. That would give me voltage drop I believe? Meter should read 0 for that correct?

On the volt scale going from ground to ground you'll see nothing. If you go positive batt to negative case is where you'll see any voltage difference compared to across the battery posts.

.....thought maybe the relay needed to be jumped as well?......

Not sure on that. In key start any voltage on it?
See post 3 here...……..
Starter won't engage when key is turned.


Does seem to me 12 V to the positive coil (hot wire) should fire in start or run with the key switch unless somethings acting as a kill switch on you?
Do you have a tach or condenser on the coil you could take out of the system while testing?

 

[Mattax]

Hi Matt, yes it did fire up normally a few days ago. Now cant get it to fire. Measured coil +ve to batt +ve and got 10.34v. I thought I would give it a full 12V direct from batt +ve to coil +ve and it doesn't even turn over.

So it may be sparking, and the problem may not be electric supply to coil or ECU. Right?
Get a tester and you'll see.

 

[4spdragtop]

Thanks Dave, I will give that link a read thru.
It cranks with key so I'm sure relay is good? I have also jumped direct at starter relay with screwdriver and it cranks. Relay was new as well.
I will pull ecu and check mounts for ground. Also for harness connector tightness.
Voltmeter is a "no name" Innova. I checked it against another to verify. Seems good? See pic.
I got a hunch there is more than one issue. I gotta read thru my previous test results but it seems like an intermittent voltage drop leading to the key.
2nd possible issue, could my upgrade to 70+ be wired wrong?
Up until the past couple days, I didnt realize you measured for voltage "drops" the way Mattax drew it out. Again a visual learner here lol.
Thanks!

Out of curiosity, what DVM are you using?


It may be just fine as is.
I know paint, especially when new, is a hard thing for anyone to scrape off just for a solid ground. Coating on the ECU case can be an issue as well. A ring terminal and separate ground wire under one of the bolts might be an option to consider.


On the volt scale going from ground to ground you'll see nothing. If you go positive batt to negative case is where you'll see any voltage difference compared to across the battery posts.


Not sure on that. In key start any voltage on it?
See post 3 here...……..
Starter won't engage when key is turned.


Does seem to me 12 V to the positive coil (hot wire) should fire in start or run with the key switch unless somethings acting as a kill switch on you?
Do you have a tach or condenser on the coil you could take out of the system while testing?

 

[4spdragtop]

Got a spark tester, I'll try later. Still got me baffled, no issues cranking with key, but nothing with 12v direct to coil +ve??
I forgot in previous reply to Dave that I do have a factory tach. I'll disconnect that to eliminate that as well.
Thanks Matt.

So it may be sparking, and the problem may not be electric supply to coil or ECU. Right?
Get a tester and you'll see.

 

[4spdragtop]

Got time today, I checked for resistance in coil+ wire with it and yellow at starter relay unhooked. With key in start. 0 ohms, so good there.
Checked brown "start " at ballast cranking, 11.24V, same as battery cranking, so good there too.
Removed tach wire from coil -ve to remove it from problem.
Reset distributor reluctor gap .008". New cap and rotor I ALSO ADDED AN ENGINE TO FIREWALL GROUND STRAP.
Fired right up!
Dunno what fixed it but all seems good "fingers crossed".
I had to reinstall headlight switch and ignition switch. Also splice taped a couple of connections from the MAD Bypass.
I rechecked and started the car after reinstalling every individual piece. Started normally every time.
I put a larger factory key switch plastic terminal connector on the back to help with tight connections. That made installing ign switch a pain in the arse!
Working for now, so line up storage and better planning for proper repair down the road.
Thanks all.