Xfi cam sync and driveshaft speed?

[Mike E]

I've got two questions. First is about the cam sync. I have an inductive cam sync setup on my belt drive. It's set at roughly 110* by the balancer. On the dashboard, it shows it at 12* at idle and when the rpm accelerates it goes up to a steady 86*. Is that normal for it to move? Why does it not match the physical setting. Crank reference is 61* on my setup. Could the polarity be backwards on the sensor? I have verified it is set correctly by pulling 10* timing from #1 and checking timing on the balancer for #1.


Second. For the life of me I can't get the driveshaft speed sensor to read on the dash. DS RPM and VSS MPH both read 0. I verified it has 5v going to the red wire and the sensor gap is set to .050". I'm going to try to move it around some more tomorrow just to be sure. Is there any way to test to see if the sensor is good?

 

[Dusty Bradford]

Yes it's normal for it to move but it sounds like its moving enough to jump from one cylinder to the next. Have you checked the timing on #1 when it shows 12 and also when it shoes 86?

Is your ds sensor feeding into the CAN stream? If so do you have CAN enabled in the settings?


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[Mike E]

I'll check the cam sync more tonight.

The Driveshaft sensor is hooked into the VSS plug on the stand alone harness.

 

[Mike E]

Is your ds sensor feeding into the CAN stream? If so do you have CAN enabled in the settings?

This put me on the right path. When I was trying to get the sensors to show on the FAST dash, I enabled all 3 CAN functions. When I disabled CAN TCU, the driveshaft started reading on the dashboard and dash. Thanks, Dusty. That's the second time I've created my own problem, but I'm getting there.

I have to have someone help me check the cam sync at the higher number, it only goes to 86 when the engine is coming up on the brake.

 

[Mike E]

After installing the AMS and swapping my 100psi to the fuel pressure, I have a spare 200psi sensor. What is more valuable data to have Backpressure, Trans line pressure or cooler pressure?

 

[CGASTON]

I've got two questions. First is about the cam sync. I have an inductive cam sync setup on my belt drive. It's set at roughly 110* by the balancer. On the dashboard, it shows it at 12* at idle and when the rpm accelerates it goes up to a steady 86*. Is that normal for it to move? Why does it not match the physical setting. Crank reference is 61* on my setup. Could the polarity be backwards on the sensor? I have verified it is set correctly by pulling 10* timing from #1 and checking timing on the balancer for #1.


Second. For the life of me I can't get the driveshaft speed sensor to read on the dash. DS RPM and VSS MPH both read 0. I verified it has 5v going to the red wire and the sensor gap is set to .050". I'm going to try to move it around some more tomorrow just to be sure. Is there any way to test to see if the sensor is good?

Hey, contact NORBS..... He had a similar issue with his. He will square ya away. Do you have a caspers volt booster on your car?


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[Dusty Bradford]

I like reading all three of those pressures. 200psi probably wont read accurately. Your main line should be over 200#. I'd want backpressure reading for sure.

If you can move your cam sync you will probably need to move it so it doesn't skip to the next cylinder. I've had to do the same with the disributors.

 

[turbobitt]

After installing the AMS and swapping my 100psi to the fuel pressure, I have a spare 200psi sensor. What is more valuable data to have Backpressure, Trans line pressure or cooler pressure?

My thoughts on priority,
1 Back pressure
2 line pressure
3 cooler pressure

I do have all three in mine but I use a 5 bar sensor for back pressure. The regulated 5 volt sensors tend to drift a little less than the unregulated 12 volt sensors.


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[norbs]

It could be a noise issue, but I would say 110 degree's is to close to 120 degrees, so I suggest you physically mount it at 85 degrees and see how it reacts. The xfi needs to have a cam sync 10 degrees before a crank signal, for processing time of the signal. However things can get a little unstable at idle, so 85 would be a good reference.

 

[Mike E]

I'm going to remake my cam sensor mount so I can get it closer to 80* and swap to a hall effect pickup. There just wasn't a good spot with the belt drive distributor in the way to get it to 80 with the bracket I had made. I'm also going to put another set of holes in the crank trigger to get it to 50*.

I obviously had a cam sync problem. When I brought the car home from BG last weekend, I took it for a spin around the block. When pulling away from a stop it would go dead lean and take a while to clean up and go. There was nothing in the tune that should have caused it. So, I switched it to bank to bank and it ran great on the same tune. I put ~20 miles on it friday night and it drives really nice.

 

[norbs]

By reducing your crank reference angle you will only be able to run 10 degrees timing less 50 so 40 max, but i dont really need to see the need to run more. Have you adjusted the inductive delay time at all for the crank sensor?

 

[cdsttype]

Inductive pick ups don't work well with the xfi the noise comes from the alternator. I have fought this battle kill the alt
power the signal becomes stable. I went msd hall cam sensor works great.

 

[Mike E]

By reducing your crank reference angle you will only be able to run 10 degrees timing less 50 so 40 max, but i dont really need to see the need to run more. Have you adjusted the inductive delay time at all for the crank sensor?

It's still set at 40ms. I locked the timing at 32* and ran it up to about 4500 and it stayed steady on the balancer.

Inductive pick ups don't work well with the xfi the noise comes from the alternator. I have fought this battle kill the alt
power the signal becomes stable. I went msd hall cam sensor works great.

You put a hall effect in that distributor I sold you?

I have an inductive pickup on the crank and it's only about 4" from the alternator case and seems to be working fine. The shield is grounded right next to the sensor. The RPM line on the datalog is pretty smooth. The alternator has it's own power wire to the battery that is run as far away from everything else as possible and has it's own ground wire to the frame.

The plug wires had drooped down so that they were just a couple inches from the cam sync wiring. On the stand alone harness I have, the cam sync shield only reaches the back of the intake. I think I could make the inductive work, but the Hall effect is almost a sure thing and surprisingly it's cheaper (doesn't matter now that I'll have both).

 

[cdsttype]

Yes i put a hall effect in the dist. It has the same thread size and the magnet is the same. I had shielded wires
everywhere and dedicated grounds. One would think it was the ignition system causing the problem
as did I. What i noticed was when the battery was was up on base charge less alt ripple the cam timing
smoothed out. When i shut off the alt problem gone. so i changed over to hall problem solved.