F4i with motec help

[Dan Kuratko]

Our team is trying to get the f4i started and we have no spark. The starter and fuel pump are working. I have been told that the motec is not sending signal to the coils because it is not getting a proper ref/sync signal from the cam pulse and igntion pulse generators. Has anyone dealt with this problem before? I've tried everything I can think of so far.

Dan

[Dan Kuratko]

Our team is trying to get the f4i started and we have no spark. The starter and fuel pump are working. I have been told that the motec is not sending signal to the coils because it is not getting a proper ref/sync signal from the cam pulse and igntion pulse generators. Has anyone dealt with this problem before? I've tried everything I can think of so far.

Dan

[Charlie]

Check for injector pulse. This will narrow the problem down to igntion only or RPM signal in general.

The M4 had good diagnostics. You say you've tried everything you can think of, well how about telling us what that is? http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Scott Harsila]

Yea, a little more info would be good. Are you getting ref/sync errors? What kind of coil driver are you using?

[Colin]

Can you see RPM getting detected on your laptap when you turn over the engine? if so your ref is producing a signal so check your sync signal. The problem with the factory sensors on these engine's is that they are reluctor pickup type and not a hall effect. hall effect sensors have a transistor inside them that produces a nice square wave, reluctor pickup's are a passive device and produce a sine wave style of signal. The problem with them is the signal is not symmetrical so MOTEC need's to be told to pick up the signal on the leading or falling edge if this is not correct the engine will not run properly. The only way to know which edge to choose is to view the wave form on an oscilloscope. The other thing with these sensors is that as the engine increases speed the voltage amplitude increases so the trigger voltage need's to increase with RPM, you set that in Mag Sensor Levels, if these are not set right you will get all sorts of errors. Here's our voltage levels but I can't guarantee they will be the same
Ref Mag Levels
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
1.8 1.8 1.8 1.8 2.5 2.5 3.0 3.0 4.0 4.0 4.0

Sync Mag Levels
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
1.4 1.4 1.4 2.0 2.0 3.0 4.0 4.0 4.0 4.0 6.0

As for polarity you'll have to work that out your self as it depends on how you wired it up. These sensors are a pain in the ass but once set up they are more reliable than a hall effect.

Good luck

[woollymoof]

Further to what colin said.

When we were trying to get our engine started on the dyno we forgot to modify the stock cam trigger wheel.
The stock trigger wheel has three teeth and MoTeC requires only one. If you haven't modified the wheel motec will be getting three signals instead just one and will be getting confused. Grind off two of the teeth, it doesn't matter which and set your crip angle appropriately.

[B Lewis @ PE Engine Management]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Colin:
The problem with them is the signal is not symmetrical so MOTEC need's to be told to pick up the signal on the leading or falling edge if this is not correct the engine will not run properly. The only way to know which edge to choose is to view the wave form on an oscilloscope. <HR></BLOCKQUOTE>

For the F4I, you want the falling edge (negative going zero crossing) of the pickup sensor when the sensor has the following connections:

- Solid Yellow Wire = + Signal
- Yellow w/ White Stripe = Signal ground

Feel free to give me a call or contact me offline if you still have problems (513-777-5233)