neonoodle

I drove my wrecked 00 Civic Si to my friends house, pulled the motor, wiring, axles, ac, brakes, etc. and put them all in my sisters 98 Civic LX Sedan. I used the engine harness and main interior wiring harness, dash board, main relay, fusebox, all from the Si, which ran perfectly before the motor was pulled.
Anyways, the car started up fine, no CEL or anything. I ran it around the block, and it ran great just like before. I parked the car, and the next time it started up just fine like before, but the moment I put the car in reverse, it shook died out and the CEL came on. When I went to start it again, it had to crank for a long time, like it wasn't getting fuel, then it started.
I was able to drive it around the block with no obvious problems. I tried to get the CEL code by jumping the connector, but instead of the CEL flashing, the SRS light will go off when it's supposed to and then come right back on and stay on. When I unshorted the connector the CEL still stayed on and the SRS light went off as normal.
I tried to reset the ECU by pulling the battery for and hour or so, and when I plugged it back in the CEL was still on before I even started the car. I've reset the ecu many time trying to figure out what is causing it, but it seems to be permanently lit.

When I put the car in reverse it doesn't die out anymore, but the rpms shoot up to around 3K, and when I take it out of reverse they drop so low that it's about to stall, and then rise back up to normal. When driving the engine doesn't feel like it's running smoothly anymore, and won't rev past about 4K rpms.

I'm all out of ideas and the CEL isn't being one bit of help. Can any of you help me?

Oh and if it might have something to do with it, all the years I've had the Si it's been hard to put it in reverse, like I'd have to slam it in sometimes.

raidacaipo

you did a 99 civic motor swap into a 98 civic? hrmm and your using the 99 civic harness and main interior wire harness and dash etc?? they wont match.. I would put all the harness from the 98 back into the 98 civic including the engine harness.. then start all over again. They are different 96-98 civics and 99-00 civics.. one uses obd2a while the other uses obd2b. You best bet is to modify the original wire harness from the 98 civic.. its not that hard to do or get a 96-98 civic ex wire harness that comes with all the sensors already there.. example vtec, vtec pressure switch etc..

btw what ecu are you using? the stock si ecu?

neonoodle

I'm using the Si ecu. I've heard of people doing it in hatches without any problems. I mean all the sensors for the engine and their connections to the ecu are on those two harnesses, engine wise everything that is different between obd2a and obd2b has been replaced with obd2b wiring.

geneeunit

if you've replaced the underdash with the si's it should be fine..