Weird issue going on with S300 or laptop or something else.

[PR8urvtec]

I have been having a strange problem for the last month and I can't seem to figure out what is going on.

Car: 1990 Acura Integra LS - B20B turbo - P75 ECU w/ Hondata S300

Street tuned
B20B turbo
GM 3bar MAP
AEM FPR
R/C 550cc injectors

Before I explain, there are no check engine light or other issues with the car. The was driving perfect for a while and all of a sudden I'm getting these problems.

Problem 1

When letting my car run for about 15 minutes or so, with my laptop connected, my a/f on hondata will start to lag and not "keep up" with my a/f gauge (AEM wideband). I have the voltage offset set setup correctly and it works when I first start the car up then it will start mess up and go out of sync and or lag on the laptop end. I have never had an issue like this before. It's also doing it on my CRX using a P28 ECU w/ S300v2 on it. To me it seems to be my laptop or Smanager having issues. I can't datalog and fine tune my p/t b/c I can't get good readings with all the lagging.

Problem 2

After the car runs for about 30 minutes (closed or open loop) the fueling all of a sudden goes very rich. My gauge shoes 10.00 for a/f and it goes to 12.xx a/f at idle. When in closed loop I usually idle at 14.2 (my target set by voltage using my wideband o2). The car will drive perfect until it just goes rich. Once this starts to happen my a/f is never really correct. IT's either to lean or very rich. I can feel the engine breaking up with I'm getting these readings so I'm assuming the fueling is messing up and not just a bad reading.

I can send my calibration and get a datalog to people who want to take a look. The car has been street tuned and is only using 5.5psi. It runs fine in boost. Just really rich on p/t for and after 30 minutes of driving.

I have changed the FPR to rule that out but the problem is still around. It happens open or closed loop. Under normal conditions in closed loop, I don't see to much correction happening with my Strim and Ltrim b/c my tune is pretty close to my target.

My battery voltage stays ~14.0v pretty much all the time and even with my headlights, fogs, ect... on the lowest voltage is 13.8v with the same fuel problem. I thought maybe my voltage was dropping and my deadtimes were maybe off at a lower voltage.

My next thought was maybe some sort of temp. correction taking place but why would it happen way after my car is warmed up. The next thing was maybe my wideband o2 is taking a crap but why would it happen during open loop as well as closed loop. I will note that my car is converted to obd1 and the resister box has been deleted to use the R/C injectors.

Anyone with any knowledge please help out. I have searched for some answers or related problems and I can't find anything or I'm not looking in the right direction to my problem.

[Spunkster]

You need to post the calibration as well as a datalog showing the issue.