Difficult Ignition Cutout Problem

[cordes]

Thanks guys. I put it all back together today and cleaned it up. It's really a very decent looking year round car in my opinion.

As for the crimp tool I used, it is the following: https://crimpsupply.com/tools/packar...-12085271.html

I bought it because the HP Academy guys on youtube suggested it was the only way to go for a durable open barrel splice tool. It's apparently made to do the metripack series of terminals, but I found doubling up with this tool made it very decent for the LM terminals.

The Logic Module terminals I used were part number: 08-50-0023. They say they're for 18-22ga wire. I would agree with that, but the insulation on the stock wiring is a tight fit at the back. Especially for the two ground wires which go to the intake manifold. In all, the crimp tool with these terminals produced some very professional looking results, even if it took a while.

I'll add that I used my Paladin wire stripper, which helped to make quick work of that portion of the process. https://www.amazon.com/Greenlee-1113.../dp/B0006BHCFO

I believe Kniepex makes one of this style now, and it's in the same price range if you can catch it on sale.

Thanks again to everyone for all of the help through this process. I couldn't have done it without you guys.

[jpcturbo]

Thanks for the PN and links! I hope the car is enjoyable for years to come.

Jeff

[cordes]

Well, I'm back...

The car ran really well for nearly 1,500 miles before I finally conceded that the problem never really went away, but took a longer interval of time to present itself.

As a result, I've converted to MS3Pro Mini. This has simplified things dramatically, as it's run by a single computer fed from a relay triggered by the J2 wire.

It's doing essentially the same exact thing as it was before. It'll cut out and the tach dies when this happens. Now that I'm using MS3Pro Mini, I can also see the lost sync counter go up by 1 each time it cuts out.

In the past couple days I have used the Load Pro to put a load on the J2 circuit at both the #8 fuse, and also the connection at the AC cutout relay. I've disconnected the AC cutout relay to remove it from the equation. The only thing which the J2 circuit does is feed the #8 fuse (it's on the bus with #7, but that's unpopulated) and also the MS3Pro Mini relay. Both of those check out fine with the load pro. The most drop I got out of any connection with the Load Pro was .3v. That is inline with my experience before, so I'm calling the J2 wire itself good.

I checked both of the main feed wires at the ignition switch today and they came to nothing when I attempted to use the switch bracket for a ground. I took a 14ga mil spec wire from the column to switch mounting screw and ran it to the body. Now the voltage hardly drops at all when pressing the button.

I guess I could try a different ignition switch again, but that seems like it's just throwing another part at the car.

Here is the log file. I don't know what I'm doing with that, but perhaps it's useful to more advanced users.

https://drive.google.com/file/d/1YX1...ew?usp=sharing

ETA: This is probably a better datalog. I used the datalog tab to start this one, so I'm assuming it captured all the data.
https://drive.google.com/file/d/16um...ew?usp=sharing

[cordes]

Great success today. I was able to rule out the ignition circuit by isolating the MS from the J2 circuit. I just made a wire to activate the MS and fuel pump relay directly from the battery with a fuse inline to act as a switch.

Next, I'll need to figure out how to test all of the individual sensors and alternator I guess.

[wallace]

Are you using any of the original wiring/hardware? I posted in your other thread what hall sensor are you using? These are the worst problems to fix.

[cordes]

Are you using any of the original wiring/hardware? I posted in your other thread what hall sensor are you using? These are the worst problems to fix.

There is no original wiring or even connectors for any sensor with the exception of the coils. I did some more testing today after installing a new alternator on account of the fact that it stopped charging the last time I fired up the car. The car will crank, and I never saw a crank signal at all. I changed out hall sensors and held it right against the crank trigger wheel while my wife craned the engine over. There was still no signal.

Being that there were two sensors to not see a signal, and the wiring has tested good, I'm inclined to think it's the ECU. The fact that the alternator stopped charging has me now thinking that's bad in the ECU also. Since it was getting absolutely nothing, I'll take the alt in to get it tested tonight and see what the report is. If it's good, then it's a problem with at least one output in the ECU at the least.

[cordes]

The alt tested good at the parts store, so I'm really starting to think that the ECU is to blame.

[wallace]

You're using mega squirt? If so it's easy to burn the trace on the board between the pot and processor pin. Check with an ohm meter. You can jumper to the top of the processor pin if so.

[cordes]

You're using mega squirt? If so it's easy to burn the trace on the board between the pot and processor pin. Check with an ohm meter. You can jumper to the top of the processor pin if so.

Thanks for the tip. I had contacted DIYautotune and they said that if it's a bad board etc. they would warranty it. Frankly, for what their hourly rate is, I'd probably just have them do it anyway. It really rubs me the wrong way that I'm still having such problems with this car, but I also know there is a learning curve to anything new.

Ideally, I will hear back that the board or some driver was bad and then be all set. Otherwise, I'm going to be beside myself with this one.

[jeff1234]

I appreciate your tenacity, it's tough to get beaten time after time but a win will be totally awesome. Im betting on you!

[cordes]

Thanks, Jeff. There isn't really much more I can do to make this car right. It will be wonderful to drive it when all is said and done. I do love the H body cars. This one has enough rust on it that I will drive it year round and just fight the rust for a decade or two.