Aaron Cake

iTrader: (1)

Radio Shack is not what it once was. But try a music shop. Most of the time they sell microphone cable by the foot and it is very well shielded. It's actually fairly robust cable which I guess is no surprise considering what it has to stand up to.

Craze8

I did just that yesterday and installed it today. No such luck, sync loss counter continues to climb under tps or fan command. with loss code 11. Haven't added a resistor yet, I did check the air gap of the cas on the two tooth pickup and it is currently tighter then a business card and checked the 24 tooth as well. Starting to believe my cas is my overall issue, even added a ground from the megasquirt ground pad to the engine.

Should I open the squirt up and play with the pots?



Next bit is a little ramble, as I try and reson this out with myself

11 is too few teeth before second trigger. So, does that mean the 24 tooth wheel is giving me my loss codes? checked its airgap as well. both are tight to a business card. looking at the composite logger I can still see phantom 2 tooth counts.

Craze8

Interesting find. Its something in my factory connector. Looks like the pins may be spread too far. Wiggle the connector itself and the sync loss counter stops dead in its tracks

Aaron Cake

iTrader: (1)

Another old CAS issue strikes!

Swap the connector with something modern like a 4 position WeatherPack. Means you can easily swap another CAS without swapping the connector of course. Well I guess you could make a little adapter harness.

Craze8

Yah it seems its truely an old cas issue. I went from having a sync loss counter to swapping the wires for the two pin connector to seeing the counter stop to now having the primary drop out at random. Seems I need a new trigger setup or a new cas. (new to me) i wonder if that one pick an pull still has a bunch.

Craze8

So revisiting this. I got a cas out of a known good running car and installed. After failing to install the cas properly, (And then getting it in right) I set the timing and the car was doing great. It would start and run I didnt have to pedal it to get it to run and overall seemed smooth.

Went for a drive and powered through 1-4. Good. In 3rd gear at about with a load, (Like accelerating up a hill) 2k-3k it drops tach and bucks. Interesting thing. When this happens, I hear relays clicking at the mega squirt, one of course is fuel pump the other is the main relay. Looking at the composite logger I have spots in the log where it flat out has nothing with the report of "Controller Gives no Signal."

Going to open the box back up tomorrow and adjust the main board conditioner alittle and see if this doesn't improve this situation as others have suggested.

Aaron Cake

iTrader: (1)

Did the Megasquirt actually reset? If so, check your power and grounds.

Or did it just lose the CAS signal? If so, then there is either a wiring problem between the CAS and 'Squirt or a problem with the VR conditioner. Or a CAS issue itself.

Craze8

Ive ohmed wiring on the cas circuit. Checks good. Squirt was purchased made from dyi autotune. This cas will at least start the car and not buck and be angry and idle and drive. (till light load at around 2-3k). I will look and double check the power/ground circuit.

For resetting. Unsure. Generally speaking when logging the composite logger I am not watching the pc. Im more or less concentrating on making it act up so I can view the log later

Odds of getting a 30 some year old cas with similar issues? Im almost to the point of parking the car till I have enough funds for the ffe trigger wheel setup

Craze8

Relay is fuel pump. No crank signal turn off fuel pump. Makes sense.

Aaron Cake

iTrader: (1)

Checking the resistance of the CAS wiring isn't a valid test. It just proves that at the moment you test the wire, under no signal or current draw, without vibrations of interference, there is continuity between the two test points.

One thing to look at very carefully are the pins on the DB37. I have seem them pushed back into the plugs resulting in an intermittent no connection. Infuriating to troubleshoot.

You can narrow it down based on the log. Which wheel on the CAS goes away?

The FFE trigger or FD trigger is of course a better option but won't help if there is a fundamental wiring problem.

Craze8

Interesting you should bring up the DB37. I have watched the log, from what I can tell when it drops, it drops the main board (24 tooth count, I would upload a log, but my laptop that had it died yesterday while looking at a digital time clock/score board, will be making a new one tomorrow on a different laptop). The complete drop out didnt happen until I moved the whole unit around in the car. I peeled the wiring back and seen that the two pins for the main board seem to move back an forth in there housing and didn't honestly think too much of it.

Any suggestions on getting them to stay where they need to be?

Aaron Cake

iTrader: (1)

I'd replace the pins.

The DB37 is convenient, but I'm not a fan for automotive use.

Craze8

Im familiar with depining automotive connectors but not db37 ones. Looks like I get to look up something new. Challenge accepted

Craze8

Update:

Tonight I overlayed the cas wiring to the primary pickup, wasnt able to locate pins at db37, was more interested in seeing if an overlay would fix the issue. It has cleared everywhere but under a very heavy load in higher gears. (4 and 5th) Didn't get it to act up in 1st 2nd and under extreme heavily load I got it to act up in 3rd. I will log it on the way to work tomorrow an see what is happening. An I will also go back and reset the pots to the way it should be instead of the modified setting I am running now. It got dark otherwise I would have done that before the test drive.

Craze8

Its something in my harness not on the cas itself. Just not sure where.

I found my cluster pickup touching the chassis ground at times. (moved coil to do so still plugged in) car ran great for 20 minutes then started doing it again under a high low higher gear low rpm.

Craze8

I feel like I am beating an old goat here. I kept seeing a double signal on the two tooth pickup. An out of a wild hair, I changed the gap on the primary pickup to be wider. As it was it was already as tight as a business card. So, I made the gap wider in the pickup on the primary side. Lo, the double signal went away. Feeling confident I went for a drive, car already seemed to be doing better. But then it still had that dumb stumble. So I did an ignition log and now have attached a screen shot, maybe someone can make some sense of the log, as I cant at the moment.

Aaron Cake

iTrader: (1)

Do you have a power drill that you can use to spin the CAS up to speed? If so, you can spin the CAS by wrapping the gear in electrical tape then using the appropriate sized hole saw over the taped gear to spin it. Many corded drills can go up to 4000 RPM or so. See if you still get noise. Because at least that will tell you if there is a fundamental issue with the 'Squirt or wiring, or you are facing some other noise or intermittent issue.

Oh, goes without saying that for this test you disconnect the fuel pump and injectors.

Craze8

Found it late last night. I got frustrated. I went back to the music store and bought a new cable and reran the secondary pickup. No more bucking and now only has an occasional 11. I could likely close the gap on the primary but I am leaving it alone so that I can actually use the car for whats left of the autox season. All I can figure is that the cable was faulty somewhere. An I couldnt find it with a ohm meter. Thanks for your help aaron

Aaron Cake

iTrader: (1)

Bad cable will drive you nuts. Years ago I was in an argument with someone else as I wanted to replace a cat-5 run at a customer's place. The PC (Windows 98) was always crashing, losing network connectivity, etc. Jacks had been replaced, patch cables, different port on the patch panel and hub, network card replaced multiple times, system reloaded, etc. People wouldn't accept that a simple cable could be bad. Finally ran a new one last thing on a Friday when no one was paying attention and no issues since. So a tiny break somewhere, maybe if the cable has been pulled too hard, or the insulation at the factory was not perfect...