Hondata

Vehicle: 92 Honda Civic EX (EH9) D16Z6

ECU: USDM P28

MODS: Hondata 4 bar MAP sensor, S300 w/ boost control socketed by HONDATA

The problem exist very intermediate, this is the only graph I could get after about 20 times of trying and failing. Finally the problem is recorded, everything is very smooth before approximately 14:10. It becomes very rich (below 10:1 AFR RICH on PLX wideband) and bucks violently any throttle position above 0% (in the recording I maintain a steady throttle position according to my foot but yet % changes drastically). After a scary ride lasting to approximately to 14:32 everything is smooth as it should be. When this problem occurred in the past it may become extremely lean above 20:1 AFR. This problem recording is very short, in long term cases (that I do not have recorded) the AFR bounce from very rich to very lean in no change in the table position, being in OPEN LOOP (ignition and fuel map) Their was a few occasions it buck so violently until the engine stalled, after having extreme problems of idling. If I get a better recording, I'll update my post. Thank you for having this service and if you need any other information please do not hesitate to ask. d16z6_civic

Penny for your thoughts?

It is not in ASCII.

Hondata wrote:It is not in ASCII.

Gotcha, but about my problem, that would be greatly appreciated

Part of your problem is how you have the AF/voltage tables set up in the closedloop tab. You only have it set to read an AF of 0 to 10.8.

Spunkster wrote:Part of your problem is how you have the AF/voltage tables set up in the closedloop tab. You only have it set to read an AF of 0 to 10.8.

Note taken, thank you Spunkster.
At this time I have it in OPEN LOOP, my PLX is standalone and not communicating with the ECU.

d16z6_civic wrote: At this time I have it in OPEN LOOP, my PLX is standalone and not communicating with the ECU.

Yep im having issues with my PLX aswell.

FreshDA9 wrote:

d16z6_civic wrote: At this time I have it in OPEN LOOP, my PLX is standalone and not communicating with the ECU.

Yep im having issues with my PLX aswell.

It is not a PLX issue, I choose to have it in OPEN LOOP and I choose have it not communicating with the ECU.

d16z6_civic wrote:

FreshDA9 wrote:

d16z6_civic wrote: At this time I have it in OPEN LOOP, my PLX is standalone and not communicating with the ECU.

Yep im having issues with my PLX aswell.

It is not a PLX issue, I choose to have it in OPEN LOOP and I choose have it not communicating with the ECU.

o i seen no communicating and thought you were having an issue

Updated tune, problem caught red handed!! Problem 2 is more potent.

You may have some kind of wiring problem because you can see the battery voltage drop off, and while it does this you also see random spikes of the TPS and the map (to as much as 25psi).

Spunkster wrote:You may have some kind of wiring problem because you can see the battery voltage drop off, and while it does this you also see random spikes of the TPS and the map (to as much as 25psi).

Thank you, Spunkster
When the voltage is decreasing it is when my engine is running a very low RPM (323RPM) and the drop bellow 10.0v is when I was extensive cranking the engine, when the engine stalled because of the problem. I would expect that the voltage decreased. I have voltage dropped most of my engine harness wiring, and did not find any faults. If you have any more thoughts, it would be greatly appreciated.

Input would be greatly appreciated.

I would suggest taking it to one of our dealers to have them look at it and possibly tune it as well.

I have had this same problem happen to me on two different occasions.
The ecu would throw a TPS code as well.

Somehow, my calibration was corrupt. I reverted back to an older backup copy that I had and everything went back to normal.

I could still open the calibration in Smanager and upload it to the ecu, but had very strange data logs and horrible drivability. Ever since this, I have kept mulitple copies of the calibration at various stages of the tuning.