Greetings all,

I initially had a IAT issue (super high IAT temps). This was caused by a ground wire coming loose grounding out pin 20 on the main board. I repaired the loose wire for the IAT but now I have lost RPM. I have tried the adjusting the Megasquirt V3.0/V3.57 VR conditioner and this indicated I might have a bad q22. So I replaced the q22 transistor and the readings got a bit better. I have a basic stimjim and all the reading came in with the printed documents. But I cannot get RPM. So I have since loaded the latest firmware to 1.6.1. Which did not change anything. So I am kind of lost now.

 

[QUOTE=Evolforce2;1665651]Greetings all,

I initially had a IAT issue (super high IAT temps). This was caused by a ground wire coming loose grounding out pin 20 on the main board. I repaired the loose wire for the IAT but now I have lost RPM. I have tried the adjusting the Megasquirt V3.0/V3.57 VR conditioner and this indicated I might have a bad q22. So I replaced the q22 transistor and the readings got a bit better. I have a basic stimjim and all the reading came in with the printed documents. But I cannot get RPM. So I have since loaded the latest firmware to 1.6.1. Which did not change anything.so I am kind of lost on what to do next. I can get some intermittent RPM on the stimjim while adjusting R56. But this is for a very short moment say maybe 2 seconds. I don’t think the problem is in U7 as all readings from pin 1 with 2 and 3 switching with one goes high the pin 1 drop grounding does the reverse as if the VR was getting signal and then grounding as it should. Oh and the car is a 1992 with a 01 VVT engine using the FM 36-2 ignition trigger. that has a T25 turbo, but the VVT is currently not working. Current configuration has been up and running for just over 2 years and 30k miles.