Cam Sync Error

At 20 degrees on balancer the reluctor is in the middle of the pickup. At least that's where I started at.
 
That won't work. You should set the rotor phasing first anyways. The problem is that rotor phasing and cam sync should not be related, but in a distributor they are as a compromise.

Rotor phasing is most important so set that first. You want the rotor to be pointed at the right terminal on the cap when your motor is making power. 20 degrees is a close enough number. Even if you are running bank to bank, you still have to set the phasing correctly. Once you get the rotor phased, the distributor does not need to move anymore, so lock it in place.

Next is the cam sync. It has a wide range that is acceptable. Minimum 15 degrees before the crank trigger, but less than 120. It can be in before any cylinder firing, but to simplify, use those numbers. Preferably, you would have the reluctor adjustable, but since there is a big window it's not always necessary. As long as it's between 15 before the crank reference and less than 120 you are good. It it's off, you have to move it so that it is. This requires you disassemble the distributor. Then you have to start over each time you pull it and move it.

I can describe how to move it, but it's a lot of trouble and yours should already be ok if it came off a running motor. So recheck it and see where it's at fist.
 
At 20 we are lined up with #1. At 75 degrees on balancer, dist reluctor is in middle of pickup.
 
Perfect. Lock it down and forget about it.

If your cam sync number on the dash is still moving around it's something else. You can change it to bank to bank and it will drive fine ignoring the cam sync.

How does it run in sequential?
 
If it is a noise problem, should I shield it all the way back to the xfi? Or try a magnet drain on one end?
Or move forward with the gas and match?
 
I have no idea about the correct way to shield it. I can tell you that the FAST stand a lone harness has a shield wire run all the way up to the Ignition connector and it's grounded at that end (I assume only that end). Then the adapter harness going out to the distributor (about 10" long) is not shielded. Of course, I had issues with this, but with my belt drive distributor it was hard to keep the plug wires away from the cam sync sensor.

I'm sure you would have noticed, but are there any metal shavings stuck to the reluctor (from dust in the shop)? That can cause issues.

I'm curious and have never tried it, so I don't know if it will do anything. But, if you can unplug the sensor and leave it in seq., will it show numbers on the dash due to noise? I've never tried it, but it may help you troubleshoot it.
 
This is a caspers harness, and I've had problems with it, so nothing would surprise me.
I'm going on vacation for a week, I need to get away from the car for a bit.
 
I can understand, mine has been "running" since september, but I've only driven it 40 miles and made a hand full of passes. It stops being fun after a while.

Run it in bank to bank and deal with it later. You won't notice any different driving it.
 
You should double check the wiring to make sure the discrete cam input is grounded and that the VR sensor in the distributor is connected to the XFI's IPU cam input.
 
The adapter harness is configured for a discrete cam and crank signal.. Since you're using a distributor VR sensor for the cam now, you need to use the IPU cam input on the XFI. These pins are probably not populated on the adapter harness and you'll need to add them. The now unused discrete cam input will need to be grounded. After you confirm all this, then you can worry about the cam signal VR polarity. The ECU's IPU inputs use a "zero crossing" detector to trigger. When a VR sensor is used, the sensor produces a current of a given polarity as the reluctor approaches it and then a current of the opposite polarity as the reluctor retreats away. The point where the reluctor is precisely lined up with the sensor, is the zero crossing. The ECU's input is looking to trigger at the zero crossing between a positive current and a negative current. If wired correctly, this will be where the sensor and reluctor line up. If wired with the polarity reversed, the ECU will trigger somewhere between two successive pulses and likely move around a bit.
 
I have a replacement wiring harness that plugs directly into the XFI rather than factory with the adaptor kit.

The other car we converted had the adaptor harness, and casper's had terminals on the two wires that get swapped, which I believe are the ones you're referring to.

I made the same swap on my harness, A3 to C3 and A6 to A7. They are now connected like this: A7 cam discrete to A6 ground. A3 is IPU cam to C3 which I'm not sure what it is. I assume cam pickup?
 
You lost me... C3 is a wideband sensor signal and A6 is an aux. speed sensor disrete input.. C-Com help files include an ECU pinout.
 
I think the c3 is what caspers is referring to on their harness. I'll post the pic.
 
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