Here you can see a datalog with the fuel pump jumped from the diagnostic box. The car seams to work fine...

Two not directly related questions...can a I do a free air calibration with the wideband(LC1) on the downpipe???

Is there any map close to my setup(1991, MSPnP, GT2554, RX7 460cc injector, 93+ octane gas)so I can make the best of the next few hours that I have until Sunday?

As posted here by Samlo1 you can calibrate the LC1 while it is installed.

"Got on the highway, fourth gear going about 80. Went into a coast, waited for over-run, counted to 5(slowly) and hit the calibration button."


Make sure overrun is enabled.
Drive the car and coast in gear at an rpm over the overrun activation rpm. this cuts fuel. after a few seconds you should have fresh air running through your engine and downpipe so you can calibrate the lc1

I've read it in the other thread but since my car doesn't move right now The only option left is to remove it?

The air in the downpipe with the car turned off for many hours isn't 'free'?

I decided to not take risks and do the free air calibration with the wideband out of the exhaust. However either I did something horribly wrong at air calibration of the wideband or my motor shouldn't be here...

The car is 1.6, with 460 RX-7 injectors, stock fuel pump and 100 octane fuel(the best I can get here). The fuel table used is the one posted here for a 1.6 with 460 injectors and the spark table is a relatively safe one in order to minimize the risks.

In the log I could see 20-22 afr spikes(that I thought are completely fake) but the engine seamed to work nice, no knock at all and if anything I felt that the car was rich not lean.

Also every time I accelerated the car went as rich as 10 afr which seams to have something to do with ECU features I'm not aware of(acceleration enrichment?)...Any help/advice about tuning the car would be greatly appreciated...

My problem was solved thanks to your help! The car is running and everything seams to work fine. I will update again this topic when my MSPnP goes to DIYAutotune to check if it has some to do with fuel pump drive circuit in my MSPnP.

I updated with the progress of the car in the original thread in order to keep this clean and focused on the original problem.

Did you ever figure out the cause of the problem?

I had the same thing happen to me, Car ran fine with the afm, did the removal, updated the firmware, loaded the base no afm map, went to start and no fuel pressure.

Jumpered the pump on, runs great.

Maybe this is a problem on non North American cars (Mine is a RHD imported jdm roadster)?

It is possible that non USDM cars used a different fuel pump relay - or labeled the ST SIGN fuse differently.