Ok I know this has been asked 1000 times, but I tried searching a lot and still couldn't figure this out. Car is an 89 CRX DX, Z6 head, Y8 cam gear, mpfi & OBD1 conversion. The car cranks and fuel come out of the injectors, but it won't spark.

For the ignition coil test, I went off this: Primary winding resistance was 0.7 ohms and secondary was roughly 14.5k ohms, putting both well within spec.

Also checked for continuity at the TDC, CKP & CYP sensors by following Alldata, which said they should all be 350-700 ohms. They all tested between 355 and 360 ohms, so those are good as well.

Then testing the ICM, I used Alldata again, but this picture is basically the same:
BLK/YEL-chassis ground, got battery voltage.
WHT/BLU-chassis ground, battery voltage.
YEL/GRN between ECU & ICM, got 10.6mv.
BLU between tach & ICM, got 136mv.
On the jumper, B15&B17 OBD0 side splice together and go to A21 OBD1 side, which are all for the ICM (nothing in A22 OBD1 side, don't know if that's bad). Back-probing, both OBD0 pins got roughly 5.5mv, and the OBD1 pin I think got around 10mv (I didn't write down the results for those tests so I can't remember the exact numbers, but it was close to those).

Anybody know what might be causing that low number for the YEL/GRN wire? The directions don't say what the voltage should be for those, but I think it should be close to battery voltage. Someone correct me if I'm wrong. Are there any tests I should do, or any I didn't do right? Which grounds should I check? A23, A26 & B2 are all currently being grounded to a body ground under the passenger dash, since they were on the subharness.

I'm open to any suggestions.

 

B21??? - there is no B21 on the OBD1 ECU - did you mean A21?

the OBD1 igniter (ICM) wire is yellow with green stripe - it should be connected to the OBD0 thicker white igniter wire in the engine harness which splits inside the harness and becomes 2 wires, which go to B15 and B17 - the yellow green wire on the OBD1 splits inside the harness and becomes 2 wires, which go to A21 and A22

on the jumper harness:
OBD0 B15 should run to OBD1 A21
OBD0 B17 should run to OBD1 A22

voltage between A21 and A26 (ground) should be approx. 10v
voltage between A22 and A26 (ground) should be approx. 10v

 

Ah sorry, yeah I meant A21, fixed it in the OP. It's easy to get them mixed up sometimes
So based on what you wrote, the jumper MIGHT be wrong, which I don't doubt... It is connected to the thicker white wire and I noticed it did split into 2 wires somewhere in the car, which do go to OBD0 B15&B17. From there the jumper turns it back into a single wire, going to only A21 and leaving A22 completely empty (as I already said in the OP).
Also, for the voltage I tested between A21 and the part of the body where A26 is being grounded to. Would it make a difference if I back-probed A26 on the ecu connector and retested? Either way, I can easily do it tomorrow afternoon if needed.

 

I should also mention the jumper is an ebay piece from uneeksupply.. Slowly been regretting it

 

Hey now! I have a $40 eBay jumper and it works just fine. I don't remember the sellers name. Have you tried a known good distributor? I had a no spark in my OBD1 conversion because my distributor was just being a pain.

 

Was it from uneeksupply? That's what mine is. And I don't have another dizzy to try, but did resistance test a known good Y8 and h22 dizzy off the vehicles with similar results

 

Try and check your wiring to the distributor again. The MPFI wiring could be off ya know. Make sure you have it pinned right and just trace the pins through your conversion harness and make sure they go to the right plug.

Mine was from gccreeker by the way. $43 shipped to the US. 2 Day delivery. The wire is colored and has instructions.

 

I checked the distributor wiring countless times, but it is possible I might have missed something obvious somewhere else. And good idea on tracing pins through the conversion harness, I'll definitely do that on my free time.

 

Update- Last night I used my free time to make sure the wires on the jumper were correct. Yes I traced every single wire from the OBD1 side to OBD0 side and it's all good. Biggest headache of my life Today I decided to check the main relay since I didn't do that yet. Used this as a guide: https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/checking-main-relay-pics-2535047/
Everything on the main relay tested good. On the harness side, there was no voltage between pin 1 & 2. Found that the 15A fuse in the main box was blown! swapped in a new one and now there's battery voltage between those 2 pins and also at the YEL/GRN wire at the distributor.
So hopefully that fixes it... My battery's dead so it's getting charged at Autozone, but I won't be able to pick it up and retest anything until maybe tomorrow or Sunday.

 

Dang! Grounds and fuses first my lad!