ECU and Fuel Pump problems, Main Relay

aluminaticivic · Post by **aluminaticivic** » Mon Jun 18, 2007 10:00 pm

The car is a 99 Civic Si (EM1) with s200b, p28 and obd2-1 conversion harness. JRSC, nitrous.

So I'm driving and the motor shuts off out of the blue. After coasting to a stop on the side of the road, I see that my fuel pump is not priming when the key is at IG2 and there is a solid CEL with no code at IG2.

Pushed the car home and did some diagnostics per Helms manual. Fuel pump has power when the Main Relay harness is jumped. Everything clears out, except when I get to the last step when testing the Main Relay--it tells me to measure voltage between ECU connector A16 and B2 when the key is on IG2. The multimeter reads 11.6V when I did this test. Since this is WAY above 1.0V, Helms manual tells me to replace with a known good ECU and recheck. So I plugged in the stock Si P2T ECU, plugged in the Main Relay, put the key on IG2 and that primes the fuel pump. I didn't start the car with the P2T re: 750cc injectors.

I'm thinking bad ECU. I took the ECU to my dealer here to have them take a look. No sign of burning.. He re-flashed it. I plugged it back into the car and it is still having the same issues re: fuel pump will not prime on IG2, solid CEL.

Also, Hondata blue box has no red light when on IG2. The red/black wire from ECU to blue box is secure.

Ideas?

Post by **Spunkster** » Tue Jun 19, 2007 9:55 am

It sound slike your OBD1 ecu is damaged and will need to be replaced. IF the s200 is not lighting up, then it is one of 2 things: damaged ecu or a bad interface cable. Based on all your symptoms, I would say it is your ECU that is bad.

aluminaticivic · Post by **aluminaticivic** » Tue Jun 19, 2007 11:06 am

thanks for the reply Spunkster.

I spoke with my Hondata dealer and I will bring my ECU to them tonite for them to test. They will plug the ECU in another car and see if that primes the fuel pump on that car (Prelude). They will also give me a good Hondata chipped p28 for me to test in the Si to see if that primes the fuel pump on the Si.

Hopefully we'll come up with something after I do the above. 8)

aluminaticivic · Post by **aluminaticivic** » Tue Jun 19, 2007 9:08 pm

Problem Solved

Hondata blue box went bad. Swapped in another S200 blue box and everything works.

Hondata, is their a warranty on your blue boxes? I bought my S200b from Motorvations Motorsports and Blacktrax Performance burned my chip for my new tune. Serial number is S200-0607.

:)

Post by **Spunkster** » Wed Jun 20, 2007 10:00 am

Please call Hondata so we can troubleshoot and if needed issue an RMA and discuss possible charges.