botboy

Backstory: Got this 1999 Prelude after it was abandoned on my bosses rental property. It had been bought from an auction and story I heard was that it stopped running on the drive back. I pulled the H22A4 out, it had blown apart a piston and was locked up solid. Bought a replacement H22A1 from an earlier Prelude motor off of CL that had ~110k on it. I did hear it run before they pulled it so I know that mechanically, this engine is a good runner.

With that said, I didn't get keys when I got this car so I bought a full key/lock set from eBay. Read up on the immobilizer, wired the starter wire direct to the key and installed a Doctronic Mobilizer-AO in the ECU as per instructions on the Doctronic website. Key light on the dash is off and the PGM system has power so I don't think this is an immobilizer issue. Check engine light turns on for a couple seconds then shuts off when the key is turned to the on position, and I can hear the fuel pump priming at the same time. New fuel filter and if you crack the nut at the fuel rail its got pressure there.

Car will start given a whiff of starting fluid but dies out shortly after. So I definitely have spark and compression, but not getting fuel. I have +12V at the injector harness and no fuses appear to be out for the PGM system. Pinned a scope to the injector harness and I'm not getting anything when the engine is cranking.

From what I can find from google most of the differences between this engine and the one it replaced are pretty inconsequential from a swap standpoint (especially if you revert to an OBD-1 ECU to avoid hassles with the immobilizer and emissions) but I just want to get this thing to run like it was more or less stock. I live in a state with emissions testing so I don't want to revert to an OBD-1 ECU as getting it certified will be a pain in the *** even if it passes the sniffer test, as they hook up a scan tool and check for emissions readiness monitors during a normal emissions test. Also I'm trying to spend as little as possible to get this thing running so I can sell it.

I found a thread elsewhere with similar problems to what I'm having where they swapped a JDM H22A into a H22A4 car, one of the responses suggested that the sprocket that the ECU reads from the crank sensor to pulse the injectors is different between the H22A4 and the rest, does anyone have a picture of what the H22A4 one looks like so I can verify if that's my problem? Unfortunately the old engine was junked so I don't have it to compare to what's currently on the H22A1 in the car.

Otherwise any other suggestions to what else I ought to be looking at would be much appreciated.

JRCivic1

How did you handle the TDC and CKP sensor conversion ??? Did you move the H22A4 oil pump over to the H22A1 engine or did you convert the single sensor A4 distributor to the three pick-up OBD-1 style distributor ??? If you used the sensor equipped oil pump, then it will be important to use the matching balance shaft gear which has magnets cast into the gear near the perimeter of the gear itself and they are shaped like a half of a jelly bean. The OBD-1 style balance shaft drive gear has a smooth outer ring with a limited number of spokes radiating from the center (three or five I believe).

If you didn't change either of these options... you have found why the injectors won't fire... no TDC signal to begin the injector firing order.

botboy

I have no idea if it was original or not, but this H22A1 was in an OBD-2 car though I think it was a 96-97 Prelude. Wasn't sure if the trigger wheel would be the same between that year range and what I have (99). Distributor is not an OBD1 unit and plugged right into the 99 harness, I still have the original distributor if I need to swap it out. The crank sensor wires coming out from bottom of the timing cover also plugged into the 99 harness.

Going to pull timing cover today and see what trigger wheel looks like. Going to pull distributor cap and make sure they look the same on the inside as well. On another forum someone linked to this picture showing the correct trigger wheels for an OBD-2 H22: Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting

botboy

Pulled distributor cap - they look exactly the same underneath, same modules, plugs and trigger wheel. Don't think that's my problem. Going to start pulling harmonic balancer and lower timing cover next.

botboy

Thought some more about this as I need additional tools to get the harmonic balancer off so I can pull the rest of the timing cover -
I have a Vetronix Mastertech (very similar to the Honda factory PGM tester) which I tried to communicate with the ECU with and had no luck. Figured maybe it would let me see if its getting signal from cam/crank sensors when cranking over. Using the Honda/Acura specific card it says unable to communicate. If I try "generic OBDII" the ECU will click periodically as the Mastertech tries different communication strategies but after letting it try different comm protocols for 15 minutes it still won't pull codes, normally it figures out protocol in a minute or so and will let me access generic OBDII functions.

I know that the cable and scan tool are good because they communicate fine with my OBDII Toyota pickup

I have power at the OBDII port. If I short the service check connector the CEL just stays on indefinitely and the fuel pump doesn't cycle when the key is turned from off to on.

I have a second ECU (the original one out of the car, still has immobilizer on it) and can't get scan tool to communicate with that one either.

I was led to believe I had ECU power because the PGM fuse is good and CEL is working but wondering if there are multiple circuits I should be checking?

Would I still have spark if the ECU was toast?

botboy

Hooked a scope to ECU pins for crankshaft pulse and TDC sensor, and both are within acceptable resistance values shown in the factory service manual. When the engine is cranking they both have a clean waveform so I don't think its either one of those sensors.

Also checked ground pins on ECU as per factory manual and nothing out of place there either.

Still very confused on why I don't have any communication when I try and talk to the ECU with a scantool, other than the possibility of a bad ECU.

Going to do some more electrical checks tomorrow.