This may be a stupid question, or even stupid idea. But I was wondering if anyone has swapped in a Gen I engine and still used the LT1 ECM? I can get ahold of a nice 383 with Track1's, and was wondering if this was feasble. I'm not looking to rev over 7000 (not yet anyway) and was wondering what kind of distributor I could use with the stock ECM for timing, or if I'd only use the fuel map part of the computer. All comments welcome.

 

Injuneer is the expert on this but I remember him saying the PCM is looking from a signal from the opti else it turns off the fuel pump.

AFAIK there is no way to generate that signal aside from actually having an opti.

If you really wanted to I suppose a ECM from a 3rd gen would work. You probably want one from the SD years (90-92 I think) as they are generally considered better than the MAF setups.

 

The LT1 PCM needs the Opti pulses to function. One way around this would be to start with an OBD-I PCM, and find one of the 20 or so "Opti-Eliminator/SDI" setups that Electromotive built. The system includes a crank timing wheel and magnetic pickup. You would need the complete system, and would be limited to using the E'motive 4-coil lost spark ignition, and would have to live with the injector phasing issues. Unless E'motive has developed a way around this.... I keep hearing they have the TEC-3 system working on LT1's, but haven't seen any evidence of this.

Or, just use the Opti-Eliminator chip to synthesize the low res pulse to drive the injectors, and use an MSD CPC system for the ignition. Might work. Might need to provide a dummy load representing the normal LT1 ignition, to keep the PCM happy.... don't know.

And maybe there is something new out there these days... my knowledge of the LT1 PCM is sort of stuck in a time warp, from 2 years ago when I stopped using (most of) the stock PCM.

 

How about fitting the OPTI on top HEI and sincronizing timing

using timing light and scan tool, i think it is going to look neat,

unique and will be high and dry that is if you don't have space

limitation.

 

ive been thinking about doing this on an oldsmobile motor w/LT1 injection stuff......
jeremy