Cam & Crank Wire Routing

[cksiver]

I injected a 72 VW Beetle Conv. with a stock 1600 cc air cooled engine. While the engine need some tuning I had it running, however, the wires were all over the place...so I purchased some wire loom tape and proceeded to clean things up. Because the wiring going to my cam & crank sensors are independently shielded wire and I had no issue prior to taping up the wires, I taped the sensor wires into the wire loom. Now while engine compartment looks good, I am loosing every other cam signal and there is sync-loss issues in direct time to my crank signal (see attached data log). Does the cam & crank wires have to remain independent of the wire loom? Attached is a data log and MSQ.

[DeadStiff]

Bundling with sensor wires should be no issue, but I would avoid high current ignition and injector wires. The only time my wiring comes together is through the firewall with the MS sitting were the rear seat would be in an earlier Ghia. I've never had to terrible shoot sync issues, for others to help with the sync loss don't more information about your setup would be helpful. What kind of sensors are you using for cam and crank?

[radial]

Did you ground both shields to pin 2 iaw the manual?
It's preferable to run the Crank and cam wires as far away from ignition and alternator related wires as possible.
A composite log and tooth log will probably show you what signal is failing...a nice place to start.

[elaw]

Does the cam & crank wires have to remain independent of the wire loom? Attached is a data log and MSQ.

There's no hard-and-fast rule on this, it depends on the specifics of your setup. I've got all my wiring run together with no problem, but I'm running high-impedance injectors and don't have the coil current going through the Megasquirt (I use COP units with built-in drivers). If you have wiring for things that generate a lot of interference like coils and low-impedance injectors running in your harness, you're more likely to have problems running everything together.

[cksiver]

Thanks for all the responses. I believe my sync error is gone. Using the Tooth Logger it was clear I had the polarity reversed on my crank sensor. I changed my polarity and the car started and the sync error was not present. You can see the differences between the attached 9/28 and 9/29 data logs. Now onto the next issue; i.e. Cam Fault. As you can see in the attached data logs.

[cksiver]

Sorry about being rude.

I have 4 corvette coil near plug coils. I am using a hall sensor for the crank and cam sensors.

Both sensors are grounded to the number 2 pin.

The car ran great in the past. I just pulled the engine, installed new pistons and jugs, rerouted my fuel rails, and cleaned up the bad hair day wiring. Now I am just trying to work the kinks out, without undoing more than I have to with respect to wire routing.

Now onto determining what is causing the cam fault.

[cksiver]

Well, to bring a little closure to this thread.

I ended up pulling the sensor wires off my relay board and wiring the signal directly into the MS3 and connecting the sensor grounds to the sensor ground wire. This cleaned up all of my sensor signals except the MAP sensor and cam-sync. These I am having a difficult time determining what is causing the intermittent noisy signal. Any insight would be appreciated.

I believe the slight noise in my MAP is associated with moving to a semi-sequential ignition. Once I go back to fully sequential ignition this may go away. As for the cam sync issue, it still persist with no ideas on what to look for next.

See attached MSL.

Thanks for all the help.

Curtis