highrever

Hi guys, i have 1991 honda civic LX. I just swapped out the old tired engine and bought a used japanese engine. MY mechanic friend dropped it in and I drove it home all seemed well, however once i was on the freeway i started to notice a slight miss, or sputter upon heavy acceleration, hill climb etc, it smoothed out under light throttle, it did get progressively worse the closer i got home, about 2 miles from my house it got really bad at any acceleration level and felt like it was running on 2 cylinders and thats when the CEL came on and i guess it went into limp mode.

Well i got it home and thought it was the O2 sensor on the exhaust manifold, i just replaced that and it didnt help. Heres what it does now, it fires up fine, no CEL, idles fine, but you will get a "miss" at idle every 10 seconds or so, if i try to drive it, it sputters bad with no power and about 200 ft down the road the CEL comes on, if you turn it off and restart code goes away. I checked the ECU to see code comes up, but NO code!. it just stays solid red when the CEL comes on while driving, if i turn it off and turn it to ACC no code.

I heard the misfire while at idle and it sounded like a arc or spark jump at the rotor/cap area so i took the cap off and it was a little worn but not bad, i scraped off the oxidation and put it back on, that actually helped a small percentage and it took longer for the CEL to come back on but it still does, so before i start throwing parts at it, any suggestions?

new plugs, wires, cap and rotor seem good, since there is no CEL code does this sound like the dizzy is bad? since scrapeing off the carbon helped "somewhat"?

DJYoshaBYD

sounds like a misfire.. you need to check your ignition timing... that could cause that.. your friend should have done this when he dropped it in..

Random misfires will set off the CEL, but will not show up as a code, per se.. check your plug gap, as well..

highrever

it was the plugs and wires and a shredded dizzy