engine missing

i'll try to give all info without writing a book.. my 92 civic lx sat for a yr and a half (second time to snap crank) got a donor motor from a 95 civic. (d15b7) simple remove and replace, installation went
smoothly. just had to refigure map sensor wiring. (92 map is on the firewall, 95 is in the throttle body) everythings good, but it misses (or at least thats what it feels like), randomly. sometimes it runs smooth, sometimes rough.. it seems after a distance it smooths out and once i stop at a light, it'll start missing again. (yet sometimes i can still feel it on the highway, usually underload, uphill) once i'm going again it misses till about 2500 rpm then like a switch kicks on it runs smooth. plugs look good (used but normal wear), wires 8k-16k ohms depending on length(book says 25k max) and dont light up in the dark, checked the timing and its good, the distributor came off my motor and it didnt do this before. i still got my old motor, want to pull any thing off before i return for core then they charge me to get a part off. thanks for any help in advance
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snipped-for-privacy@hotmail.com wrote in

I don't think I would depend on the "don't light up in the dark" test for spark plug wires.It could also be a bad coil(in the dist.cap?) A 95 motor would have considerable mileage on it,so it's possible the wires insulation is going,or the "used" spark plugs are due for replacement.
BTW,did you change the ECU when you put in the newer motor? if they are different part numbers,they probably have different programming maps.
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Jim Yanik
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Jim Yanik wrote:

most definitely - first place to look. plug replacement is a top priority also.

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ok here's what i've noticed recently, starting up cold it runs fine, once i get the engine warmed up it'll start chugging at idle. ie. stopped at a light etc.. but it never dies, rpm bouncing down to 3-400. what sensors could have this effect once warmed up?
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Various engine control sensors are exposed to the cooling system and malfunction with insufficient coolant. A common culprit for your symptoms is a low coolant level. First thing to check are the coolant level in the reservoir and, with the engine cold, radiator. Top off both with coolant. Observe. If problems continue, then do an air purge of the cooling system. Be aware that the engine may have to run 30-60 minutes for the radiator fan to come on twice, as required by the air purge instructions.
The coolant to use depends on what's now in the car.
Please always state your Honda's year and exact model in posts. Some problems are unique to certain years and models.

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wrote

mileage would help,too. also if any parts have been replaced already,or any repairs done recently.(motor-related repairs....)
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Jim Yanik
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come on, read the first post!!! my 92 has 150-160k miles the motor is supposed to have 120k im currently running the 95 engine, but have swapped back in the 92 throttle body, map, tps, distributor, wires, plugs, o2 (in bottom of exh manif) my dad broke the plastic upper radiator connection and it has been leaking slightly... im glad you mentioned that, i know what i'm fixing next!!
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Oops, beg pardon jpurl. I read the subsequent post and it sounded like a new one [blah blah lousy excuses]

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snipped-for-privacy@hotmail.com wrote in

whne cold,the ECU uses a preprogrammed map to run the engine. MAP,throttle position,and air intake temp sensors are used to give a generic starting point in the map for the ambient conditions. O2 sensor data is ignored.(open-loop operation)
Once the O2 sensor warms up,in a couple of minutes,then the ECU can begin controlling the fuel input to get proper fuel/air ratio.(closed-loop operation) Once the coolant gets up to temp,then the ECU can fine-tune even further.
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On Jan 7, 8:14pm, snipped-for-privacy@hotmail.com wrote:

distributor cap has the coil in it; can give funny results also if it gets cracked or other defect. i know you said you have the one off the old engine, but if the one from the 95 is around, might be worth a swap.
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