Honda prelude no spark

Test or check the crank position sensor. Look for the 5 volt reference signal (your prelude may have a higher reference voltage- I don't know), check that the ground wire is good, then see if you get a signal from the signal wire. See if you can back probe the signal wire with the engine cranking. If the sensor is at fault, the ecu cannot determine spark timing.

Look at a wiring diagram to see if the camshaft position sensor is also part of spark timing.

how about the relay up under the dash on left side of wheel (steering)

if you have changed the distributor cap,rotor button,spark plug wires and plugs and you still dont have fire then its most likely your distributor.first check the fuses or relays if you have replaced those items.

Sounds like a bad ECU. Why did you change motors?

try replacing the main relay. location is under the steering column usually bolted down with a single bolt. this relay controls spark and fuel.

Unfortunately you probably need a new distributor. There are three pick-up coils mounted down inside the base of it. They go bad quite commonly. The unfortunate part is; the new distributor will come with a new cap, rotor, coil and module...which you have already bought. The distributors are not that expensive though, maybe you can sell the extra parts???

compression? distributor? leads? plugs? relay? electrical wiring circuiting out? any of these is a factor.

Bad distributor if the main relay was changed. Good luck and thanks for using FIX YA

I suspect that your spark plug wires or your distributor is going out. Check your spark wires and distributor. To do that take out #1 spark plug wire from the spark plug. Next take out your spark plug then put it in the spark plug wire. Then turn on car and take a look at the spark plug to see if it's getting a spark. Do this with all the spark plug. If it is your spark plug wire I would replace all of them.

Go to your nearest Autozone or other parts house and buy an inexpensive plug gapper. I gap the Honda plugs at .045 .