I recently swapped a GSR engine into my 90 Civic hatch and can't get it to start. The car was converted from dpfi to mpfi by the previous owner. The car ran fine for a long time and ran fine 3 days ago before the swap, but now it won't start. I'm using an obd1 p72, obd2 GSR injectors, no resistor box, obd2 distributor, and a obd0 to obd1 conversion harness.

I checked for spark and fuel, there is spark. There is fuel at the fuel rail, the fuel pump turns on, but the injectors have no power to them. If I put fuel directly into the intake manifold via a funnel, the engine fires right up. I get two codes, 8(TDC sensor) and 16(fuel injector circuit). All of the wiring has been gone over numerous times by myself and a few local guys who are familiar with this type of swap. I hooked up my buddies chipped p28 out of his running LS/VTEC Integra, to see if it was an ecu problem, but it didn't start with his ecu either.

I checked the main relay and all of the tests I have done check out ok, but this has been a pretty frustating day, I easly could've missed something.

After looking at some wiring diagrams I jumped pin 8(ground to ecu) on the main relay to a chassis ground and I instantly got 12v to the injectors, but the car still wouldn't start. I unhooked the jumper and found that when the fuel pump primes when the key is first turned on, the injectors have power, but after that 2 seconds the power is gone. Would this indicate that the relay is at fault? Would not clearing the codes after getting power to the injectors cause a no start condition?

Also is there a way to check the TDC sensor? I don't see it in my manual and I can't find the procedure online anywhere. Thanks in advance for any help


Modified by boost_guy at 12:18 PM 6/4/2006

 

Forgot to mention that I made sure all of the grounds were hooked up. I am not very familar with Honda vehicles, but I have two grounds at the thermostat housing from the engine harness, a ground at the valve cover to the radiator support, a ground strap from the front of the transmission to the frame rail, and a ground from the top of the transmission to the same spot on the frame rail.

I added a ground from the thermostat housing to the chassis and from the battery to the same point. I am fairly confident that all of the grounds are where they are supposed to be. What pin on the ecu do the sensor grounds go to? I couldn't find that info anywhere.

 

Just to cover the basics. Can you use a Obd2 dizzy with Obd1? Also is the wiring different for OBD2 injectors than Obd1 injectors?

 

Yes you can use an obd2 distributor with an obd1 ecu and the wiring is the same for the injectors.

 

I just found out that DPFI cars have the main relay setup a little different. Instead of power coming from the main relay at terminal 3 for the injectors, the power for the injectors comes from the fuel pump circuit . So now I'm thinking that terminals 2 and 8 that go to the ecu might be switched somehow, perhaps in the conversion harness.
But if that was the case wouldn't the fuel pump be on all of the time?

 

I just did a dpfi to a mpfi and it runs okay i didnt have to do anything with the main relay but i am using obd-0

 

Does anybody know how to test the TDC sensor?