DRFTN09

OK so i have done my research and from what i found in other threads nothing has worked. i have a 2000 si and i just recently got the motor in it. i have a b16 all obd2 with an obd2b engine harness to a p28 and im not getting and pulse from the injectors. I am getting voltage to the injectors but they arent grounding while cranking. ive cleaned up all my grounds over and over again including the one on the tstat housing. its a known good ecu and my main realy is in good working order as well. Any help is greatly appreciated.

Former User

Do terminals B2 and B10 in ECU connector B have continuity to body ground?

DRFTN09

i will check that tommorow morning. im thinking its a bad ground somewhere. anything else i should look for?

Former User

Though you don't realize it, the two ECU terminals I mentioned are grounds critical for the fuel injectors. The tests measure whether the terminals provide the necessary grounds.

DRFTN09

not to sound like a total idiot but how should i hook up my dmm for those pins

Former User

Unplug ECU connector B, touch one probe to the indicated terminal and the other to the metal frame under the dash. Do you measure 100 Ohms or less?

DRFTN09

yeah i measured under 100 ohms

Former User

At both?

DRFTN09

am i measuring key on engine off?

Former User

Key off

DRFTN09

am i measuring at the ecu or plugs off the harness

Former User

Unplugged ECU connector B

DRFTN09

I measured 30 ohms at one of them and 40 at the other

Former User

That^ resistance should be fine. Try swapping in a known good ECU to see if this solves the problem.

DRFTN09

ok im gonna go buy a new one today from a shop anything else that could potentially be causing this?

Former User

May be better to borrow an ECU for test purposes from a friend.

DRFTN09

Ok well I bought a new ecu and still the same result.

Former User

Do all 4 injectors click and pulse fuel if you ground each injector ground wire to the engine?

Are all 4 injector ground wires properly pinned to the ECU?

I also just noticed that I gave you OBD2b pin terminals to test for ground. The OBD1 terminals to test in P28 ECU connector A are A23 and A24. Post the Ohm readings.

DRFTN09

When I ground the injectors with my power probe they spray fuel and I have an Obd2b engine harness to a jumper harness then the p28. I just bought a virgin p28 and still nothin saw the ecu fire up a shop car.

Former User

Unplug ECU connector A, touch one probe to terminal A23 or A24 in the connector and the other to the metal frame under the dash. Do you measure 100 Ohms or less at both A23 and A24?

DRFTN09

im gonna go check right now ill post results in an hour. i appreciate all the help

DRFTN09

the pins on connector a23 and a24 say there for secondary o2 and my starter signal???

Former User

No. Not for an OBD1 ECU.

DRFTN09

Ok well they read 22 and 25 ohms

Former User

Do the same tests for ECU connector terminals A26 and B2.

Then turn the key to ON(II) and test whether ECU connector terminals A25 and B1 have battery voltage.

Also, what wire colors do you see at ECU connector terminals A1, A2, A3, and A5?