Alright to start things off Ive got an PNP2 with firmware 3.3.1 built 4/15. car is a 94 with a BP4W, using all 94 sensors and harness, the only change being NB light purple injectors. Wideband gauge is Innovate's MTX-l. Gauge is working properly, and was calibrated correctly in free air, and matches the reading in TS. I got the PNP used, and made sure to open it up to verify nothing was burnt or modified and all looks correct to my eyes. Loaded a 94 base map, set fuel calculations based on the injectors, and the car fired right away. Set timing to 10* and made sure to verify actual 10* with a timing light. When I make a change to a load cell, I see the expected change in AFR. In the past Ive used VE Live to get my tune in the ballpark and then fine tune from there, as it was meant to be used. My AFR table is correct for what I am looking for, but for some strange reason it tunes backwards. I mean if a cell target is 14:1 and current AFR is 13.5:1 it will richen the cell. If the same cell is 14.5:1 it will lean it. It wont stop at a certain point either. Steady state cruise in a single load cell it leaned from 15:1 out to lean missfire in about 3 minutes.


This is also not the only issue I am having. The rev limiter is not engaging. It will in neutral, but in gear, it blows right past the point its supposed to limit at. First pull I did expecting it to be there, it got to 7800 before I reacted. Engine seems fine as it was a one-off, but its a bit worrying. Doesnt matter what type of limiter I try, fuel, spark, blended, timing retard... None of it works while in gear, which makes no sense as there isint a sensor to say youre in gear or not. I should clarify, the shift lever can be in a gear, clutch depressed, and it limits revs, while in motion, it does not.


Google has really not helped find any old threads on any site with similar issues. Any directions to point me in are greatly appreciated.

 

I also haven’t heard of this happening before, but I would suggest updating/reloading the firmware. If it continues to have multiple issues like this, send it in or replace it.

 

Thanks curly. Im not new to tuning megasquirt, I had a PNP1 a while back, but I am by no means an expert. I'll give that a go and report back.

 

Firmware updated with latest version. Some change but now it does fine below a certain RPM and will just lean to infinity above that RPM. Rev limit is still acting off as well. it doesnt engage untill WAY after the point its set at, almost like the old crystal mod from back in the day.

 

can you post a log and MSQ?