I was going through some old pictures and realized I never posted the solve for this one. Turns out the tach sensor needed a spacer to increase the signal. the low amplitude trace was due to the sensor being too close. Someone had removed the sensor and failed to replace the spacer... :banghead: Hop...

Spent some time with the 907ie over the holiday. Tried putting a used ECU on (ECU was from another 907ie and had a 907ie EPROM already) which didn't solve the issue. No smoke came out of the second computer. I tried to check the outputs from the ECU to the injectors, and didn't see any signal. This ...

Thanks for all the responses. I was able to get some time in with the 907ie over the weekend. Right off, the fuel pump relay was turning on when the starter was turning. Which I suppose indicates the timing sensors are OK. The sensor pins at the computer showed some voltage wiggle on both sensors (t...

The 1991 907ie on my bench right now has no spark, and has arrived as a 'none of the shops around town could fix it' kind of thing. My hope is that the ECU and MAEs (#39 power module on schematic) are good, and I will hopefully get some oscilloscope traces this weekend, but am having trouble figurin...