hisnibs

I have a 1989 Civic STD
I got it as a rolling chassis and put my D15B2 from my CRX into it.
I used the engine harness that came with the car as it had been upgraded to MPFI and am using the PM6 ECU that was running the engine in my crx before.

I got the engine in and went to crank it and it just turned over and over but didn't catch.

since then, when I turn the key to the start position, the main relay buzzes (actually it's clicking but so fast it sounds like a buzz) CEL and the Code light on the ecu both come on and flicker so fast that it appears dim.

I unplugged the main relay, and measure the voltage at the harness. (ecu is plugged in, key turned to on)
Dash shows solid CEL and brake lamps

[1] - to battery = 12.5v
[3] - to ecu = .8v
[5] - to ignition = 12.3v
[7] - to fuel pump = no voltage

[2] - ground = 1v
[-]
[6] - ST switch (starter?) = no voltage
[8] - to ECU (A7,A8) = .8v

Previous owner had a supercharged d16 running on an obd 1 ecu with a jumper harness

Please help with this as I am a step away from just tearing down the entire harness

dephtone

Sounds like the main relay is bad. Grab another one from a junkyard and try it. They are known to go bad in EF's

hisnibs

The main relay seems to be good;
I just got a new one in my crx.
It was working a week ago.
I swapped it in and I have the same problem with either relay

hisnibs

I just checked all of my fuses; none were blown or loose
My thermostat grond is tight
I have a 2 stock ground wires running to the valve cover and a 4ga ground wire from the frame to the tranny.

Any hints or anybody else with this issue?

LightWeightED8

does the ground wire to the relay have continuity to ground?
is there voltage on the BLU/WHT cable when the car is cranking?
If not, check continuity between the starter and the relay.

If I have the colors wrong, forgive me. I'm at work without my car or a manual

On ignition [BLK/YLW] the relay should allow current to flow from the battery [YLW/WHT] to the ecu and injectors. Then once the starter engages the relay will let the current from the ignition flow to the fuel pump.

[1][YLW/WHT] - to battery = 12.5v
[3] [YLW/BLK]- to ecu = .8v
[5][BLK/YLW] - to ignition = 12.3v
[7][YLW/BLK] - to fuel pump = no voltage

[2] - ground = 1v
[-]
[6][BLU/WHT] - ST switch (starter?) = no voltage
[8][GRN/BLK] - to ECU (A7,A8) = .8v

LightWeightED8

Also, If ur ECU is flaky, then it may not be pulling the contact in the relay to allow current to flow from the ignition to the fuel pump

hisnibs

The ground wire to the relay has continuity to ground
There is battery voltage on the BLU/WHT wire when the key is turned to ign. but the voltage does not reach the starter terminal. The fuel pump however can be heard pumping

hisnibs

I just took the multimeter to the (OBD0) ECU plugs and got the following voltages
A2, A4, A16, A18 = 2.2v (Shouldn't these be ground? ie 0v)
A12-15 = 12.5v Main Relay/injector power

B1 = 12.5v hazard fuse
B13 >>> key on = .5v >>> key turned to start = 12.5v

C11, C14, C15 were depinned. Shouldn't these be my MAP sensor?

jlicrx

you are correct for all of the ECU pinouts listed

sanimalp

is your battery bad by any chance? have you tested it?

LightWeightED8

If you hear the fuel pump turning then you should have battery voltage on the ylw/black wire on the relay.

hisnibs

The car now cranks
I am seeing 0v at ecu plug pins A2, A4, A16, A18

The battery is good; It's a Optima Redtop 34/74 that I've been running from last november til last 8 days ago, at which point she went on the bench; She's still kicking out 12.6v and change, despite 8-10 minutes of cranking

Unfortunately she still wont start

Should she be able to start without a map sensor hooked up?

LightWeightED8

Depends on what harness you used. Some OBD1 harness, the MAP sensor connector goes directly to the ECU. On others, it connects to the connector on the shock tower connector and then to the ECU.

LightWeightED8

these are grounds so you would get 0V. Whats more important is that they have continuity to ground. You would get 0V on a open (disconnected) ground wire. Have you checked for continuity to ground on the these pins?

Has the main relay buzzing gone away?
Have you checked for spark? Do you happen to have a fuel pressure gauge installed?

blasterman87

double check all the grounds, my friends hatch did the exact same thing we finally found the ground to the engine harness was rusted inside the wire.. i pulled it and it broke in half and rust fell out...cut off the rust and attached it up, runs like new

hisnibs

The buzzing has gone away; I sanded the paint away from the frame rail ground point and since then I am getting continuity to ground at the ecu pins and she is cranking like a champ.

It is an OBD0 ECU (PM6) and OBD0 harness with OBD1 Injectors and no injector box.

efsihatch91

make sure the grounds are connected to the waterneck were the thermostat is it took me 2 hrs on a friends rex to find he didnt connect that lol. but his was doing the same exact thing till i connected that then it ran like a champ.

LightWeightED8

It is grounded on the water neck (G101) since the main relay is now working and the ECU is getting grounds on the 4 pins he mentioned.

hisnibs

I just spliced in the MAP pigtail to the ECU and hooked it up to the Intake manifold
It is cranking but is not getting a spark

Seems that she's throwing codes 1, 6, 7, 8, 10, 13 and 15. Yay!

LightWeightED8

Ahh, that will give you some work to do.

I would start troubleshooting the TDC sensor and Ignition sensor first. Maybe a bad distributor or igniter?

The TPS, 02 and coolant sensors can wait once you get its started. It will run shitty, but they wont prevent the motor from starting.

hisnibs

It's running now; The igniter power wire was loose from the back of the main fuse box

LightWeightED8

Yeah, wish my car was in the same state

hisnibs

I can't start it now that I've got an exhaust on it (had just an open header before)
It was throwing codes 1, 3, 4, 7 and 15.

I found that my signal wires were reversed on my MAP and TPS.

Now it just has a Solid LED light in the ECU.
I tried disconnecting the battery foir 15 seconds, but the LED just comes back on Solid.

Is my ECU fried? How do I resolve this?

LightWeightED8

Sounds fried to me.

hisnibs

Frack.
I managed to clear out all of the codes by redoing my harness from scratch.
I am not getting any codes and the dizzzy seems to test out fine (~440ohms across a-b and c-d, proper voltage at the 2p connector)

but it just cranks and cranks and cranks with no spark.

WTF?
Is this an icm or an coil/ignitor issue?