MREG2

iTrader: (1)

Ok, I've got a rather strange problem with my GSR swapped 99 EK hatch. I've searched H-T and I have yet to find anyone with a similar problem. The setup I'm running is a complete 98 OBD2 GSR swap with an unmolested 00 Civic Si wiring harness with an OEM 00 Civic Si cat and downstream O2 sensor so the car is OBD2 compliant. I'm currently running the stock GSR intake manifold and a stock OBD2A GSR ecu with a boomslang jumper harness and it has been running absolutely perfect like this for the last 6,000+ miles since I built the motor and swapped it. I had to add the wiring for the downstream O2 sensor to the engine harness since my EK's body harness wasn't pre-wired for it. The CEL comes on every once in a while for a code P0420 so I know I need to replace the cat eventually but other than that, I have zero issues running the car with an OBD2 ecu and it passes emissions without a hitch.

The problem that I am running into is when I have an OBD1 ecu plugged into the car. I am in the process of doing a Skunk2 intake manifold swap and I also have a chipped and VTEC converted P06 ECU with a Phearable basemap and a boomslang OBD1 jumper harness. After I have had an OBD1 ecu in the car for a few days, it won't start on the first try, it usually takes about three times to get the car to start and it has even gotten so bad to where it won't start for about a minute or so. Also, sometimes the car will choke out and stall leaving from a stop if I don't blip the throttle before accelerating; sometimes it won't restart right away after stalling. I have noticed that the problem gets worse the hotter it gets outside. Another thing I have noticed with the OBD1 ecus is that my headlights and interior lights dim a little unless I rev the engine past 3k or 4k rpm while at a stop and the lights fluctuate while driving. Also, it has never thrown a CEL with an OBD1 ecu. I have tried different OBD1 ecus, swapping out the distributor, triple checking my jumper harness and all my wiring and ecu plugs, I've tested the battery and alternator and I have even replaced the fuel pump but the symptoms persist.

This problem is driving me nuts because I need to convert over to OBD1 so I can get the car tuned properly and so I can run the Skunk2 intake correctly. Should I replace my engine harness or try a different brand OBD1 jumper harness?

Any ideas?

kyden

i would try using a different jumper harness. i've had issues with pins breaking off on my boomslang so i gave up on them.

i would also unplug the evap purge solenoid if you are using it.

MREG2

iTrader: (1)

I'm going to get a rywire jumper and try it and try unplugging the evap solenoid but all the wires and pins on my OBD1 boomslang jumper tested good so I'm not convinced that is the problem.

MREG2

iTrader: (1)

Anyone else got any ideas or suggestions?

MREG2

iTrader: (1)

Still need some input on this one. I bought a rywire jumper harness and that didn't fix it. I have resorted to using a vafc2 for the time being but my tuner only tunes on hondata so I'm SOL right now.

MREG2

iTrader: (1)

Update if anyone cares: I found out my 1.5 year old battery was going bad so I replaced it but it didn't fix any issues. However, I did find out that my alternator will output between 12.5 and 14.4 volts and fluctuate for no apparent reason while running and driving. It does not happen with the OBD2 ecu, only OBD1 ecu's. Alternator tested good again as it always has. Bump for little progress.