CB Magna EFI system HELP

Fuel Supply & Ignition Systems

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sniperx
Posts: 19
Joined: Mon Nov 07, 2011 10:36 pm

CB Magna EFI system HELP

Post by sniperx » Mon Jul 31, 2017 8:31 pm

I've been running the same system since 2011. I was one of the early adopters of the Magna system. Yesterday I was driving fine...then I parked it. 12 hours later....it won't start. The fuel pump relay isn't clicking and the pump isn't running. Changing the relay didn't work. Jumping the terminals got the pump running, but the engine won't fire. The software says everything is running. The crank pickup seems to be reading...I think its getting .5V AC. I don't think the injectors are firing...with as much cranking as I've done....I'd expect some fuel smell. Voltage is fine...I have 2 deep cycle batts.

The worst part is....its stuck in a pay parking lot!

HELP!

P.S. I'm in Japan so theres a big time difference here. Please answer with any ideas.

Thanks..

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ps2375
Posts: 287
Joined: Mon Aug 18, 2014 10:04 am
Location: Meridian,ID

Re: CB Magna EFI system HELP

Post by ps2375 » Mon Jul 31, 2017 10:33 pm

Is there a way to see if you are actually getting an RPM signal. Sounds like either no RPM signal or ECU went dumb since it won't prime/run the fuel pump.

sniperx
Posts: 19
Joined: Mon Nov 07, 2011 10:36 pm

Re: CB Magna EFI system HELP

Post by sniperx » Tue Aug 01, 2017 5:20 am

THanks for throwing your help out there.

I've since brought the car home so the immediate urgency is over with, but I still need a fix.

I hooked up the laptop to see what's going on. I'm getting a tach signal, about 200rpms cranking. No power at the coil with key on. I'm running a distributorless system with a two wire pickup on the tone wheel.

I'm thinking the ecu lost itself someway. I can hear the IAC running and other signals show up in the software....but for some reason the run time and total hours are zero and the fuel pressure says 70... key on or off.

I need the password from CB to flash the ecu. This is kinda my last hope...

sniperx
Posts: 19
Joined: Mon Nov 07, 2011 10:36 pm

Re: CB Magna EFI system HELP

Post by sniperx » Mon Aug 07, 2017 9:14 am

Well, after working with Mark at CB we've narrowed it down to a tiny component in the ecu. We thought it was the relay, but I tested it and it energizes and connects, so it must be the little surface mount transistor in front of it.

While trying to energize the coil and injectors, I ended up hotwiring the thing to work. I jumped the key on/ignition to the energizing pole on the fuel pump relay and VIOLA the whole thing works.

So I have a short term and long term solution here.

Thanks to CB, they've always been there from startup through tuning and finally troubleshooting complex issues. Having now been inside their ECU...it is very simple and robust. There are no standing capacitors or anything to break off from vibration. The whole board is lightly coated on both sides with a basic hard sealant. The transistors that power the injectors are off the shelf and the heat sinks are screed to the housing with appropriate insulation. The system is really well built.

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