Hi everyone!
I have a N/A S2000 with Js intake, new spoon throttle body with sensors, t1r pulleys, Flywheel, mugen header and Js Exhaust. Car also has a spoon head gasket and a walbro fuel pump (also bought new)
Last thing was the AEM series 2 which i bought new from the dealer.
Car with all above parts run fine with the OEM ECU.
To complete my car, i bought a new AEM series 2 from the dealer.
At first, I used the car without a wideband, just with the stock sensor.
Car run fine for 4-5 days, lets say about 100 kilometers and then my car stopped working properly through the entire powerband. I didnt had an AFR gauge to check but it was obvious that the car had at some RPMS too rich or sometimes to lean AFR. It also burned my Exhaust packing material.
After that, i contacted the tuner (Tuner has tuned many S2000 N/A and FI) and after installing a wideband sensor with a gauge, he verified that the car was running a AFR of 11-11.5 on full throttle, and the overall performance of the car had nothing to do with the performance of the first days.
We tuned the car for a second time. Same thing again. Car performed perfect on the first 80-120 kilometers, and after that started to lose the adjustment of the tuner.
It burned for second time the repaired exhaust packing. On full throttle i saw AFR between 11.5-12.5 mainly on the mid range RPMS. On 7000 RPM AFR changed to 13.1 and seemed again to work properly. Sometimes it continues to work at ~12 even at higher RPMS.
I decided to find another tuner, well known to tuned dozens of S2000, Racecars and others.
After the tune, car had a really great operation and an unbelievable throttle response.
At my way home, after the tune and about 50-70 kilometers, car started the same unpropper operation, with AFR in the Midrange at 11-12, specially after rev matching downshifts, when it sometime hits 10 and car stops accelarating. After i hit on gas again, it comes back to 13.
Actually, my car i this whole year never opperated properly and burned 3 exhausts. wierd thing is, 2 of 5 logs where destroyed files and the graphs were not readable.
I m guessing it is a shitty fuel pump but my tuner is sure it aint.
If anybody had the same problem, please HELP!!!!