Suzuki 1.0-liter ignition

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Dave Hodges

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I put an HEI module on a 1.0-liter Suzuki engine. It senses a signal from the distributor pick-up (the camshaft position sensor), and triggers the primary side of the ignition coil. It runs but doesn't run good at high rpm unless I remove the bolts from the distributor cap and turn the cap several degrees past the adjustment range. My question is: Is there a lightweight electronic gizmo that will advance the timing? I don't want to have to use a heavy MSD box.
 

Hot Wings

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. My question is: Is there a lightweight electronic gizmo that will advance the timing?.
Yes. It is the OEM control unit. But I can see why you may not want to use that.

Other than something like the MSD you could stir together something yourself using a $2 Arduino. If you do it that way you can use the signal from both the crank and cam position sensor. The crank sensor will provide a more stable signal relative to the actual crank position. An added bonus is the ability to continue to run, till shut down, if one of the sensors fails.
 

Dave Hodges

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Thank you Hot Wings. The car and the computer didn't come with the engine. I replaced the throttle body with a carburetor. The Arduino sounds good. But I wouldn't know where to begin with it. I was hoping someone knew about some electronic gismo that could be snapped in between the camshaft position sensor and the HEI module, or something between the HEI module and the primary side of the coil.
 

Dave Hodges

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Does the CPI work on a three-cylinder engine? Does it change the amount of advance timing to match the rpm? Can it be driven by the signal from the camshaft position sensor?
 

Toobuilder

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CPI is a wasted spark system so I think a 3 banger is out. Other than that, CPI is user configurable for RPM and MP (completely user adjustable curve). Its triggered with a hall effect sensor on the flywheel.
 

Hot Wings

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Does the CPI work on a three-cylinder engine? Does it change the amount of advance timing to match the rpm? Can it be driven by the signal from the camshaft position sensor?
You might ask the guy that builds them (RV6ejguy). It appears that they do not. Another problem is that your cam sensor is the inductive or VR type and the CPI uses a hall trigger.

I presume you are still using the the stock sensor and distributor? If so you might be able to use a VR signal conditioner and only one channel of the CPI module. But if you can find a local hobbyist familiar with C++ and Arduino this should be a pretty easy project. There appear to be 2 ways to do what you need. One is to replace the the factory ECM with the Arduino and code. This means knowing how that system works and what kind of signals are used. I don't remember the details. Haven't fiddled with an HEI for nearly 20 years.

The second way is to replace the trigger signal with the Arduino and code. You will need the VR signal conditioner to give the Arduino a clean signal. The HEI was designed for the VR signal. The Arduino can output any signal profile you choose.

Either way won't use as sophisticated a timing profile as the CPI unit but it should be as good as any mechanical advance.
HEI.jpg

Edit:
If you just replace the trigger signal you may have to ground the 3 ECM pins to keep the timing from floating?
 

KeithO

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Jackson, MI
You might look into this solution that is marketed to tractor owners with obsolete engines. The Ford module apparently has built in advance. To start the engine you crank it with the ignition off so it can build some inertia, then flip the ignition on.
http://gardentractorpullingtips.com/ford1.htm

You can correspond with the author, he can explain. He also shows how to use the GM HEI modules on his website, but the ford module is the only one that claims advance characteristics.
 
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