Hey guys, I just bought a 90 civic and it is in need of a bit of help. It had a mini me swap which blew up and was swapped for a d16z6 (and appropriate p28 ecu). The harness has been re-wired a bit by rywire to run obd1 (has a resistor box) but does not control vtec. It also has the harness for the 4 wire O2 sensor, which it seems all the wires are hooked up properly. The problem comes in on cold start...car idles well and a rev via wot the car will rev to red line no problem. When I give it partial throttle it will sputter and the rpm's will drop to between 200-500 rpm's (if I keep holding the throttle down it will die). This happens below 2200 rpm's, above 2200 rpm's car will rev fine at partial throttle. When the car is warmed up (about 7 minutes and the temp is around 1/4 of full scale) everything works pretty well. There is still a very small amount of hesititaion but it is pretty much non-existant. I gave the car a tuneup when I swapped the new engine in (new plugs, wires, cap, rotor, pcv, and filters) and also made sure all vaccume lines were good. I was thinking the 4 wire O2 sensor is not wired up properly/faulty or the tps is failing/has failed but I just changed the TB out for a stock one (had a b16 tb on it) with known good sensors and all is still not well (the tps may need to be calibrated which I will be doing tonight). Also the car is running rich...not sure why but I am thinking it could be related (the car makes plumes of carbon behind it at WOT and leaves spatters of carbon on the floor when I start it). Thanks in advance for the help! O yeah, also it isn't throwing any cel's/codes

 

Today I reset my ecu and the car was a lot easier to start (it has progressively been geeting more and more difficult to start). DO you think it could be a bad ecu?

 

Somebody on another forum recommended I check my main fuse. Plausible? I think so. Anybody have a link for checking the main fuse?

 

I know that the main relays have a problem with cold solder joints and you can actually re-solder them to correct the problem. This happened to my CRX, whenever I would go to start it, it would only turn over. Whenever you go to turn the key you should hear the fuel pump priming the system. If it does this intermittently then I would suggest you try to re-solder or purchase a new main relay.