Looks like our comments were deleted from the other channel, figured I'd try here instead. Okay, what about installing the SMFI injectors, and just wiring them up to batch fire? You'd have to get the resistance fairly close to the original injector, but that shouldn't be difficult. The only issue with doing that which I can think of is the fuel delivery amount, but you could install an external fuel pressure regulator and fine tune it if needed. I have worked on a bunch of the 4.3 and 5.7 with the SCPI injectors, fuel pressure is critical for proper operation. A little too much pressure and they leak, too little and they won't fire. I've never worked on the single CPI, but I would imagine it's the same. I can also tell you from experience, I've gotten brand new distributors that were faulty multiple times in a row(from Napa). I had to use an oscilloscope to check the signal strength and found at idle the waveform was there, but the voltage was too low. They would idle poorly with misfires and randomly misfire off idle.
Don again thank you for sharing, my CPI fired all six at same time said to be okay. I read in article written by recognized professional automotive writer that SCPI fires one at a time so would I not need to replace the powertrain management computer and update wiring to support SCPI? I used to have 10 mhz heathkit o-scope that I built myself I used until heathkit went bust. I may have to buy new o-scope. I have my original distributor and can swap it back out when I have time if I can not get the timing figured out.
@@dennissytsma3561 I meant, install the electric SMFI upgrade meant for the 96-99 years. Then wire the injectors in series/parallel to achieve a close resistance value to your current maxi injector. (to keep the driver happy inside of the pcm). It's the simplest, most cost effective way I'm able to think of to upgrade your system from the unobtanium injector you have now. The poppets of your spider look identical to the original poppet of the 96-99. I'm sure they are close enough to not matter. Since the SMFI conversion was meant to be a direct replacement for the poppet system (no pcm update or reprogram, just a part swap) I'm betting that you would have no running/performance issues at all. But if you did, it would be as simple as adding a adjustable external fuel pressure regulator.
@@dennissytsma3561 the "S" in SCPI or SMFI stands for sequential, meaning each cylinder fires independently of each other. So yes, you're correct, it would be a huge task and expense to convert your system from CPI to SMFI. However, it's a relatively simple task to convert a readily available SMFI spider to a batch fired MFI spider that your current PCM will happily run.
Looks like our comments were deleted from the other channel, figured I'd try here instead.
Okay, what about installing the SMFI injectors, and just wiring them up to batch fire? You'd have to get the resistance fairly close to the original injector, but that shouldn't be difficult.
The only issue with doing that which I can think of is the fuel delivery amount, but you could install an external fuel pressure regulator and fine tune it if needed.
I have worked on a bunch of the 4.3 and 5.7 with the SCPI injectors, fuel pressure is critical for proper operation. A little too much pressure and they leak, too little and they won't fire. I've never worked on the single CPI, but I would imagine it's the same.
I can also tell you from experience, I've gotten brand new distributors that were faulty multiple times in a row(from Napa). I had to use an oscilloscope to check the signal strength and found at idle the waveform was there, but the voltage was too low. They would idle poorly with misfires and randomly misfire off idle.
Don again thank you for sharing, my CPI fired all six at same time said to be okay. I read in article written by recognized professional automotive writer that SCPI fires one at a time so would I not need to replace the powertrain management computer and update wiring to support SCPI? I used to have 10 mhz heathkit o-scope that I built myself I used until heathkit went bust. I may have to buy new o-scope. I have my original distributor and can swap it back out when I have time if I can not get the timing figured out.
@@dennissytsma3561 I meant, install the electric SMFI upgrade meant for the 96-99 years. Then wire the injectors in series/parallel to achieve a close resistance value to your current maxi injector. (to keep the driver happy inside of the pcm). It's the simplest, most cost effective way I'm able to think of to upgrade your system from the unobtanium injector you have now.
The poppets of your spider look identical to the original poppet of the 96-99. I'm sure they are close enough to not matter. Since the SMFI conversion was meant to be a direct replacement for the poppet system (no pcm update or reprogram, just a part swap) I'm betting that you would have no running/performance issues at all. But if you did, it would be as simple as adding a adjustable external fuel pressure regulator.
@@dennissytsma3561 does this make sense? You're upgrading to a SMFI part, but then wiring it to be MFI batch fire.
@@dennissytsma3561 the "S" in SCPI or SMFI stands for sequential, meaning each cylinder fires independently of each other. So yes, you're correct, it would be a huge task and expense to convert your system from CPI to SMFI. However, it's a relatively simple task to convert a readily available SMFI spider to a batch fired MFI spider that your current PCM will happily run.
@@dennissytsma3561 the Heathkit oscilloscope will be fine. Try it on your old distributor, spin it by hand and look for at least 2 volts peak to peak.
did you test for the pulse signal?