My idle misfire is back (has been back for a few days now).

I downloaded a EFI circuit diagnostic check for 7730 ECMs from the site DIY-EFI and it says that with the engine running I should see 2.3V at the distriubutor reference terminal at the ECM. IT's the purple with white stripe wire at pin BD8 (circuit #430).

Since I'm only showing 0.6V there, I'm wondering if I have a problem.

Does anyone know off hand if this is indeed a problem. Or ayone with access to their 7730 computer, could you take a voltage check at that terminal and let me know what you get??

Thanks very much in advance!

 

Anybody???

 

Guys, I could really use some help on this. Looks like 40 people have viewed this post... is there anyone who can do a quick check for me??

 

I wish I could help. Bump to top for you.

 

Utm8Z,
Not sure how much help this is, I'll not be able to check the ouptut on my dizzy until Monday 12-29-03, but check out this page on the subject of coil output voltage amplitude.
Hall-effect sensor waveform
Although this maybe true I wouldn't want to be an exception to the average output of other dizzys, and it may be that the ignition signal amplifier requires a minimum voltage (maybe .6 volts is slightly below minimum) to recognize it as an valid ignition pulse. I would prefer the ~2volts stated by DIY-EFI.

Since the GM HEI uses a Hall-effect switch this is a good example.
Other sensor waveforms can be found at Pico ADC212 PC Parallel Port Virtual Oscilloscope

Her's another page that talks about distributor pick-up coils.
Tech Tips

 

rgarcia63,

Thanks much! I'll look forward to your results.

I took a look at that Hall Effect article. Interesting, but I'm not sure it really offers up any new avenues for me to pursue. I'm really close to buying a brand new wiring harness and rewiring the EFI system.