Hey guys, I picked up an '89 CRX Si a few months ago in running and driving condition, very stock. Long story short, had a bad head gasket and a head bolt hole was stripped. I picked up a ZC for a good price and swapped it in but thus far I have been unable to get it running. It seems like the computer isn't firing the injectors but I'm not sure why.

Current symptoms:
- Engine turns over but won't start
- Cam timing is correct (or at worst off by 1 tooth, but looks good)
- I have spark at the plugs
- Fuel pump primes and fuel comes out of fuel rail during cranking
- Spark plug wiring looks correct for a ZC( http://i38.photobucket.com/albums/e1...ngorder2-2.jpg)
- Original Si engine harness, with original resistor box (original MPFI car, didn't wire extra injectors)
- Used injectors off of original D16A6 (with still original resistor box)
- TD03U distributor repinned
- Stock PM6 computer with no check engine light when cranking, no blinking on LED on ECU, check engine light comes on for 2 seconds when key on then goes off.
- CYL sensor on exhaust cam measures 893 ohms, which is in spec
- Engine will run if carb cleaner spray into intake
- +12V at injector connectors verified

I can't figure out why the computer isn't firing the injectors. Any ideas or places to start?

 

couldnt get the print out you posted.
i had the same problem a month ago on a frieds rex ZC.
it was the firing order, which is totally different than the d series.

 

I've checked the firing order several times, and I'm pretty sure I got it right, especially since it will run if I add fuel.

 

when you turn the ignition key to 'on', does the check engine light come on for 2 seconds and then shut off?

are the ground wires coming out of the engine harness connected at the thermostat housing, clean and secure?

 

Check engine light does come on for 2 seconds and then go off.

Ground wires at thermostat are definitely connected, however it can't hurt to clean them again.

 

This is pretty normal to happen on a car with a failing main relay.
Although it seems unlikely (but not impossible) that is the problem since your CEL is going on and off properly.
Unplug the resistor box, turn key to the 'on' position, and check for 12+ volts from chassis ground to the one different colored wire in the resistor box harness connector.
That will troubleshoot 1/2 the possible problem.
If you get 12v then it's all good.

The other half would be the negative signal. That starts at the distributor, then to the ECU, then to the injectors.
First stop would be your grounds and a close second would be the distributor.

 

With the key on I do have +12V at the injector connectors, so I think that part is good. The car ran fine before with no starting issues, so I had ASSumed the main relay was still OK.

The distributor is brand new, however I guess it is possible that the wiring still isn't correct or there is a bad connection. I guess the test to do would be measure from the distributor itself back to the ECU and verify continuity.

Thanks for all the input!

 

I thought I would update this thread. I haven't worked on it much lately, but I finally got it running today. Apparently I'm just a dumbass and had the distributor wiring incorrect (the TDC sensor was mixed up with crank sensor). I could have sworn I tried this combo before, but it's running now. Thanks to all who posted!