There's a lot to be said here so I'll try to sum it all up as quickly as possible:

I have a b16a1 w/ a JRSC and Hondata Stage 2b. Entire setup was originally installed in a 4th gen civic sedan. Was tuned in this car and ran great. Attended multiple races with it and never had any CELs. The sedan turned out to have some frame issues so everything was swapped over to an '88 civic hatchback. EVERYTHING was swapped over except for the chassis side wiring. Finally got the car running and took it to its first autocross. Now here's where the problem comes up. Car will launch great. Can run through 1st gear and into 2nd w/o any problems. Pulls very strong. However, if I let off the gas then roll onto it in 2nd I almost immediately get a loss in power and the CEL pops on for code 3, MAP sensor error. I am able to reproduce this every time I drive the car. Obviously the car barefully runs after this b/c of limp-home mode.

Here's another strange thing. While attempting to datalog with Hondata's Hondalogger, I lost connection to the ECU as soon as the CEL was thrown. I noticed no strange readings before that. I wasn't able to reconnect after that unless I turned the car off then back on. However, ONE TIME I was able to hit "Reconnect" repeatedly until suddenly the CEL went away, the ECU cleared itself of its codes and the Hondalogger reconnected to the ECU. It's almost like the whole system was reset. Why would that happen? That's not what the Hondalogger is supposed to do. I called Hondata and they said it sounds like a voltage spike issue.

Here's what I've done as far as diagnostics/troubleshooting goes:
- tried 2 other MAP sensors, same outcome; it obviously isn't the sensor
- checked voltage from the ecu as outlined in the service manual; all is well
- checked continuity from the plug back to the ecu; 0 resistance, all is well
- my tuner suggested it may be the main relay f'ing with the voltage to the ecu; I swapped that out with a known good one with no luck
- checked all of the grounds; no issues there

So, at this point, I'm at a complete loss as to what to try next. It's looking like there's some issue with the chassis side wiring in the new car. The next thing I'm going to try is to test resistance between the ECU and all of the sensors/relays in the rest of the car.

I guess my question is, does anyone have any hint of an idea of what may be causing this? I simply don't understand why it would pull so strong when I run through the gears, but it f's up when I roll into the throttle. It's beyond me. Has anyone ever experienced anything like this before? Any hints on how I should go about checking for voltage spikes or voltage losses in the system or to the ecu??

Sorry this post is so long, but I think I covered everything. Thanks for reading...

Josh

 

 

back up top...somebody has to have some ideas

 

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Bump for good question!!!

 

Wow, that is really weird. Maybe rewire the map to the ecu?? You proved me wrong in everything I thought could cause the problem.