MSefi.com read only forum (Jan.15,2018)

Guys,

I have 85 camaro, at first i was trying go get it to run on the stock 7 pin HEI, it started but rpm signal issues made me pull out the hei module. I installed a hall sensor rpm pickup using 4 magnets on the flywheel and the bip 373 ignition module. I wired it all as DIY autotune describes. rpm signal is perfect but i dont have spark anymore. ground of the coil is on pin 36, i checked it has 12v on the coil. dwell control is set on the default values. didnt change this after the HEI to bip373 swap.I dont have a clear idea about what my trigger offset should be. how can i calculate this? and what does MS use for triggering the ignition?

anyone suggestions on what I can check/ or is there something wrong in the msq of msl?

Thanks guys

Most common crank trigger is a 36-1 toothed wheel and wasted spark. The missing tooth tells MS where a piston is, ie TDC. How have you achieved this with your magnets?

Correct me if I'm wrong, but the '85 Camaro has a distributor, so 4 crank-speed triggers is all that's required.

Looking at your log, it's certainly trying to spark; at 4397 the spark advance goes from 0 to 15.7, while at 4398 the dwell climbs from 3.1 to 4.5 by 4400.

Have you installed your internal jumpers? JS10 to IGBTIN, IGBTOUT to IGN? Have you removed R57?

@ trakkies

I have the 4 magnets on the flywheel ( as one guy advised me to do) recently another guy told me to reverse on of the magnets to mark the TDC position, the other guy said it wasn't nessesary. but it sounds logical to reverse one magnet.. can not find this anywhere on the web.


@ Don

Yes i have done all jumpers as diy autotune website states. can it be that i'm way off with my trigger offset value in the msq? I more or less guessed it a bit.

Interesting. I dunno if MS would recognise a reversed magnet signal from a VR sensor as the missing tooth. However, are you still using the distributor as well? If so, four pulses from the crank could be used to time a spark at each one, as Don says. But the dizzy needs to have the rotor arm/contacts in phase with those pulses. What does a timing light show?

FWIW, I don't thing a hall sensor will produce a different signal from a reversed magnet, unlike a VR one which would. A hall sensor just produces switched DC - an VR one an AC signal.

However, you should be able to get a reliable tach signal from your setup. What input circuit are you using for the hall sensor - and which hall sensor are you using? Some need a pull up resistor - some don't.

Trakkies,

The hall sensor setup gives a clear rpm signal (i dont get my rpm from the distributor, used a pull up circuit indeed). a reversed magnet would just give No signal because the hall sensor triggers only from one side of the magnets.
and yes i use the distributor for now, so i think the problem is that the trigger offset must be set quite accuratly because otherwise the contacts from the distributer are not lining up. i pulled out the plugs and cranked, no sparks on different plugs. so a timing light doesn't show anything i guess.

So is it just a matter of trying different crank angles? or am i missing something?

I have placed one of the magnets on the flywheel about 50 degrees btdc, as I was told by someone who already used this kind of setup. would this mean my trigger offset should be about 50 degrees? (setting it correct with a timing light as soon as the engine runs offcourse)