From time to time, I receive emails asking for help and I generally send an email back to the original sender and consider the matter closed. Sometimes, these answers to these questions are general enough that others could benefit from seeing the answers, so I’m starting a Reader Mailbag section of the site. Send in your questions and I’ll publish any questions that could help others.
My name is Eric, I’m Bam’s friend he told you about with the CRX? Anyway, here is the trouble I’m having. I have a 91 CRX HF shell, that bam had previously swapped the guts into off of his old 91 Si. When I got the car it had a pretty much dead motor, the car still ran, but it had no compression, so I swapped the motor. The motor I ended up with is a D15b6 out of a 91 HF. So the motors in there, and has the correct motor harness, PM8 ECU, connected to the Si’s dash wiring. Here’s the catch, everything works, except I’m not getting spark? I have fuel, I have compression, but not spark. Plugs are new, I’ve tried swapping dizzy’s, ECU’s and checked connections, and can’t seem to find a problem? and am at a loss as to where to look next? Any help or insight you could give me would be awesome.
Well Eric, there are a few causes that you can check for. I would go about this by process of elimination. Systematically eliminate problems in the chain, one component at a time. Start from the end result and work back until you find the source of the problem.
- Spark plugs — Inline spark testers are inexpensive and work well, but you can also test them the old-fashioned way. Unscrew the plug from the engine and put the diode (the end that would go inside the engine) close to bare metal and crank the engine. If a spark jumps from the diode to the bare metal, the plug is functioning correctly.
- Spark plug wires — Test spark plug wires with a multimeter or a test light. Plug one end into a power source and the other end into a test light. If the light doesn’t turn on you can be relatively sure that the cable is bad and should be replaced.
- Distributor — The most common malfunction with distributors is a worn cap and rotor, which will prevent spark plugs from receiving electricity that would allow it to create a spark. It’s also a good idea to make sure your distributor timing is correct (check with your manual) using a timing light (available at most local automotive stores).
- Ignition Coil — An ignition coil is essentially a capacitor which stores electricity and powers the spark plugs (the distributor just controls when the coil and a spark plug are connected, the coil is the power source). Most Hondas (including your CRX) use an internal coil, meaning the coil and distributor are one unit. Since you’ve replaced the distributor (and I’m assuming you tested it to make sure it worked in another car, or bought a remanufactured one that had been tested), you should be in the clear on both the coil and distributor.
- Fuses — Check the fuse box under the dash, on the driver’s side. There should be a fuse labeled ‘ignition’. Is it blown?
- Relays — Relays are a great idea to put in cars, until you have to start troubleshooting. The main relay on obd0 cars are notorious for dying on all Hondas, and are generally in terrible locations (close to the fuse box under the driver’s side dash). There’s a good writeup on tegger.com that discusses them.
- ECU — Since you’ve already swapped the ECU for another pm8, this is probably not the problem. Double-check to see if the ECU is throwing any codes (a blinking light on the ECU itself is a good indication).
- Wiring — If you check everything above, the wiring harness or connectors are most likely at fault. Since so many CRX owners upgrade to obd1 (or even obd2 in some cases) wiring harnesses are inexpensive online and you should be able to get a replacement without breaking the bank.
I definitely want to know how this turns out, so be sure to update me directly or on the forum (link below). I hope to hear that this is sorted out and your HF is purring like a kitten soon!
My beater's better than your Beamer.