Hondata

Hi All,

Sorry for the NOOB question.

I have a 1974 Fiat X1/9 that I've swapped a K20A3 into.
Software version 4.4.2.0


I think I have it set up correctly. The immobilizer and multiplex are both off. I'm using a K20A2 intake so the secondary intake runners are disabled. The car cranks strongly but I am not getting spark (based on observation when it's out of the cylinder and grounded) and am not getting fuel (spark plugs dry). Fuel pump seems to be working fine. It primes with ignition on and pressure is about 60 psi on fuel rail gauge while cranking.

In the datalog, the main thing that appears awry to me is that the voltage drops down to about 9V when I'm cranking. I've tried two batteries and both do the same. They are both on the older side but work fine in the cars they came from and were both fully trickle charged before using.

Questions:
1) Could the battery voltage be the cause for the no start. If so, what is the reason, i.e. does the ECU not send spark/fuel if too low?
2) Anything else funky that any of your experienced eyes note in the calibration or datalog?

I appreciate any help. I've been working slowly on this thing for several years and am excited about finally getting it fired up.

Why the K20A3 rather than a K20A2?

Check your main relay wiring and that it gives voltage to the coils. Same with the injectors. From the datalog both should be working.

I'm guessing it's going to be a wiring problem, but I can't figure out where yet.

I'm getting voltage on engine harness 20 (black/white wire) via the main relay, so the coils should be getting power. However, I pulled a spark plug, grounded it and plugged it into the coil and I am not getting spark while the engine is cranking.

The plugs are dry, so I don't think the injectors are getting power either.

Would crankshaft position sensor do this?

I went over the wiring again today and it all looks right to me. I tested the relays as well and they appear to be working correctly, too.

Thanks for any suggestions you can offer.

p.s. K20A3 because I got it for free!

Try the ECU in a known working vehicle. If it works then you will have to start going through the wiring.

I resolved the problem - it was just stupid wiring errors. The plugs to the fuel injectors looked like they were making contact but they weren't, and the 20 pin off the C101 also looked good by visual inspection but wasn't actually connected/providing power to the coils. After resolving those two issues it started right up. Thank you for the help.