cam sensor

[Supra]

hello guys

we are using a motec m4 on our honda cbr600 engine and i had everything wired but the problem is when ever i try to start the engine the cam postion in the motec does not change it sticks to -1% and i dont have any ref or sync errors. both the cam and ref sensor are magnetic stock sensors. i managed to get a hold of the service manual and did the timing manually for the cam shafts since we have removed them eairler. the engine wont start. the crip value is 420 with the two short teeth getting grounded of. please if someone had a simialr problem try to help

[Supra]

hello guys

we are using a motec m4 on our honda cbr600 engine and i had everything wired but the problem is when ever i try to start the engine the cam postion in the motec does not change it sticks to -1% and i dont have any ref or sync errors. both the cam and ref sensor are magnetic stock sensors. i managed to get a hold of the service manual and did the timing manually for the cam shafts since we have removed them eairler. the engine wont start. the crip value is 420 with the two short teeth getting grounded of. please if someone had a simialr problem try to help

[PBnG]

If you are getting spark, check the timing with a timing light. For cranking / idle you want to have around 10 or less degrees of timing. The lower pointer should be pointing to the lone line while setting CrIP. The other two marks should be near the upper-right notch of the cover.

I think cam position is related to where it triggers between the ref teeth. It should not change as the engine is moving if that is the case. 50% cam position would mean it's pulse is spaced evenly between two ref pulses. Verify your rising/ falling trigger settings with an oscilloscope, otherwise as the engine revs your CrIP can become inaccurate.

Disclaimer: I'm a goofball and have never used an M4 (we have one) but I have played with its menu to compare settings with the M400 we do use.

[Poe]

PBnG, don't worry about being a goofball -- everything you wrote applies to the M4 the same as the M400.

Supra,
When you installed the camshafts, did you time it based on the lobes closest to the gears or the ones farthest away? We put our engine back together once timed off of the lobes closest to the timing gears and wouldn't start (no compression).

Also, are you sure the CrIP value is correct? You may know this already, but the CrIP is determined by the crank angle between the crank tooth immediately following the cam trigger pulse and TDC #1 on compression stroke.

[Supra]

Poe,
i installed the cam shafts as shown in service manual this is what it says:
1- turn the crankshaft clockwise and algin the "T" mark on the ignition pulse generator with the index mark on the right crank case cover(Top dead center).
2- install each cam shaft on the correct location.
3- make sure the timing marks on the cam sprockets "IN" and "EX" are facing outward and flush with the cylinder head.

after i have followed this proccedure, i turned the crank shaft 7(210 deg) teeths to align the cam tooth with its sensor then i aligned the crank tooth with its sensor so now its 8 teeth(240deg) then 720-240=480 deg this is what i got but when i tried to start the engine seemed not to like it so i changed it to 420 the engine want to start but it didnt. the injector pulse width is 12msec.

note: i have changed the cam shaft timing this week last week the cam shafts where in the wrong place and all we got is backfires from the intake now none but we have exhausts backfires.

[Grant Mahler]

Try 4ms cranking fuel.

[Poe]

Clocking the cams would only be an issue if the gears were removed from the cams. It sounds like they are probably okay there.

How many teeth are on the crank trigger wheel, 12? If the TDC does not occur at a trigger point on the crank, the CrIP will be slightly different than the tooth spacing multiplied by the number of teeth.

[Supra]

Poe,

the crank wheel has 12 teeth evenly spaced.

[Supra]

guys today i played a littel bit with the motec to see if i can get the SRP to change, what i found out is when i put the crank ref teeth to zero the SRP goes to 30% but the crank ref teeth is 12 when i put this value the SRP stick to -1%. does the ref/sync mode has anything to do with this. like if it was 11 rather than 14.

[Poe]

It's been a while, but I seem to remember the 11-14 being different combinations of rising and falling edge trigger settings for the cam and crank. Hit F1 and see if there is any additional help because I can't remember exactly which was which.

[Supra]

Poe

i tried to the modes 11 to 14 and tried to see if the SRP changes, what i figured out was that when i used 13 the SRP went to 75% and sticked to it, at this time the spark plugs were out and injectors were off when i have put everything back the SRP went back tp -1% another thing is that the sensor wiring is very close to the ignition wiring and starter wiring.

[Poe]

What mode do you have for the triggers? I think we had to use low level mag setting for the stock Honda sensors.

[Supra]

Poe,

we are using both magnetic ref and sync sensor and ref/sync mode is 14 falling falling

[Poe]

Try the low-level setting. Have you tried looking at the signals on an oscilloscope? The constant -1% makes me think it's not getting proper signal and the computer is never sync'ing

[Supra]

here is a ref/sync capture the sync signal was reading 400mv and ref signal was reading 4.5volts

http://img36.imageshack.us/img36/7448/04112009107.th.jpg (http://img36.imageshack.us/i/04112009107.jpg/)

[Supra]

here is the ref/sync capture, the ref singal was reading 4.5volts and the sync was reading 400mv
[img=http://img36.imageshack.us/img36/7448/04112009107.th.jpg] (http://img36.imageshack.us/i/04112009107.jpg/)

[Supra]

[img=http://img36.imageshack.us/img36/7448/04112009107.th.jpg] (http://img36.imageshack.us/i/04112009107.jpg/)

[PBnG]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Supra:
the sync signal was reading 400mv </div></BLOCKQUOTE>

That is a fairly low sync voltage. At cranking I would expect to see at least 2.5 volts from both sensors. Typically the ref and sync sensors have approximately the same voltage magnitudes at a given speed. Low magnetic sensor voltage can be caused by a bad sensor, bad wiring, or improper clearance to the trigger.

[Supra]

PBnG,

the sync sensor clearance is the stock clearance we have'nt changed anything to the trigger teeth on the cam shaft.

[PBnG]

That sync voltage is so low that depending on the Sync sensor setting (trigger filtering) the m4 may be seeing that as noise and not an actual Sync signal, especially when cranking slower with compression (speed will oscillate and the voltage will be even lower.)

You did grind two teeth off of the stock cam trigger wheel. I am just making sure the one that was left was not trimmed at all.

[Supra]

today i have tried to play around with the modes given in motec i have put the ref sensor to be high magnetic and sync to be very low magnetic, on this setup the sync position has changed to 65% but went back to -1% so sometimes it reads the signal most of the time it does not.

[Poe]

I think we had ours on very low setting for both ref and sync when we ran the M4.

[Gaanja]

@ supra,

Are the wires for the crank and cam sensors shielded and grounded properly? Also the crank pulse envelopes need to be more pronounced. If you need a screenshot of the pulses i can mail you one. We use an M800

[Supra]

Gannja;

thank you for your help, i would like you to send them to me on my e-mail b00025259@aus.edu