24TEN

iTrader: (2)

SUMMARY UP UNTIL POST #14:

No start condition, previously shown CEL code 16 (fuel injector) intermittently over a month or so prior. Car died while waiting at a traffic light.

Key on II:
-ECU Fuse (engine bay) receives voltage
-Distributor plug shows voltage
-No voltage to yellow/black wire on the resistor box wiring plug (harness side).
-Showing battery voltage on ECU plug A, pin 13 and pin 15.
-Main relay showing battery voltage on pin 3 and pin 5.
-Continuity shown between main relay and resistor box plug harness side.
-Fuel Injector plugs read .02v at the connector
Key on III:
-Starter Signal Fuse (under dash) receives voltage
-No continuity shown between main relay and resistor box plug harness side.
-ECU pin B13, gets voltage while cranking.

Tested:
Ignition Switch
-All circuits show continuity per the FSM
ECU
-Replaced with known working unit, no change
Distributor
-Replaced ignitor and coil with new units, no change
-Replaced complete distributor with known working unit, no change
Main Relay
-Replaced with known working unit, no change

*Fuel injectors recently rebuilt




ORIGINAL POST


ENGINE-Z6 block/A6 head set up to run as a complete A6 with a bump in compression.

PROBLEM-I'll be as brief as I can be. CODE 16 (Fuel Injector) randomly for the past month but never showed hesitation or any drivability issues. Then a couple of weeks ago I was sitting at a light, car sputtered and idled very low all of a sudden. Pressed gas to rev engine up and it reved up back to maybe 800 or so but sounded very weak and died after about 3-4 seconds. Started back up but it sounded like it was dieseling or running on fumes and would die after a few seconds again, was able to do this twice before it completely died. Car will no longer start.

Initial thought check for fuel pump function, heard it prime so immediately went to check for spark. No spark. Replaced coil with new unused unit. No change. Verified voltage to the two wire plug and it is receiving 11.46 or so with the key at II. Checked visually for spark, no spark on wires when grounded. Checked for audible fuel pump prime once more and it can be heard.

Additionally, ECU fuse in engine bay checked out (I forget which one it was but it was the 15amp fuse) with similar voltage with key at II but starter signal fuse (#2 I believe, 10amp) under the dash does not receive power. I tested this per RonJ's link, continuity is good but neither terminal is showing battery voltage at all. ECU ground at the thermostat is intact. Switched ECUs altogether with no change. Also worth mentioning is that the fuel injectors were rebuilt after the initial CODE 16 CEL, ran fine afterwards and actually helped make my car pass CA emissions (it was failing prior to the rebuild).

I'm having a difficult time finding/tracing the circuit with the FSM I have, I believe I am using an 88 CRX specific one which for the most part is fine but doesn't have the cleanest wiring diagrams at the end.

Any thoughts or suggestions on what to check for next?

Former User

Do all four fuel injector clips have battery voltage with the key in ON(II)?

Did you check for the starter signal voltage with the key in ON(III)?

Can you push start the car?

24TEN

iTrader: (2)

Haven't checked those items yet but will after work today. Push start...I'm afraid, I live between hills. If it doesn't start I'm screwed and I'll have to tow it back to my house LOL. Are you getting at ignition switch?

Former User

Possibly.

Some more electrical tests also should help pinpoint the problem.

24TEN

iTrader: (2)

I'll post back later tonight. Also I was going to verify that the plug itself to the fuel pump is getting voltage just to be absolutely sure and manually verify fuel at the filter and/or regulator. I pulled the seat and saw a connector there, but I believe this is the fuel sending unit connector (hatchback). Is the fuel pump connector acccessible inside the cabin or is this only accessible by dropping the tank?

Former User

If the pump is priming, I don't see a need to test whether voltage gets there.

10A fuse 2 is for the starter signal. Did you voltage test this fuse in ON(III)?

The starter signal voltage goes to ECU connector pin B13. Did you check for voltage there in ON(III)?

24TEN

iTrader: (2)

True. Figured if it was easy enough to get to I'd do it anyway. I guess I'll pull the ignition switch and do the test per the FSM too while I'm out there later.

Former User

See extra information I added to my last post.

24TEN

iTrader: (2)

Yes, that is the one (fuse 2 under dash) that doesn't receive voltage at key position II. Continuity is good, swapped with fuse 1 right next to it since it's a 10amp also, no change. Verified at fuse 1 that the original fuse from 2 got voltage after switching it around and it did. Safe to say the fuses are good right?

Haven't checked anything at ECU side yet so I'll add that to the "to do" list for tonight.

Former User

You did not measure voltage at fuse 2 because it only receives voltage with the key in ON(III), hence the name "starter signal".

24TEN

iTrader: (2)

Doh! It was 1:30am, wasn't thinking too clearly. Will retest again correctly tonight.

24TEN

iTrader: (2)

Checked for voltage at fuse 2 with key on III and cranking. Voltage was showing but battery is almost dead. Leaning on igniter now. I have a busted dizzy I can strip one from but couldn't do it tonight because it has Torx style screws holding it in and I need to find those specific sockets in my garage. I'll update again tomorrow evening.

EDIT - Just checked B13, gets voltage while cranking.

24TEN

iTrader: (2)

Finally had a chance to check the fuel injector plugs, key on II all plugs read .02v at the connector. Tested resistance on the resistor box per the FSM and all were within spec.

EDIT: Just found voltage test procedure for resistor box, will do this tomorrow.
EDIT2: Key on II, no voltage to yellow/black wire on the resistor box wiring plug (harness side).
EDIT3: Key on II, showing battery voltage on ECU plug A, pin 13 and pin 15. On the main relay showing battery voltage on pin 3 and pin 5.

Guess I'll be chasing an open at this point?

24TEN

iTrader: (2)

Bumping this. I have some time now to look into this. Just resistance tested the wire from the main relay to the plug for the resistor box and it shows minimal resistance so this indicates there's no break in the wire. Semi stuck at this point...

EDIT: Resistance set at 20k, measured from main relay to resistor box it shows 2.4k ohms with key on II, but as soon as the key is switched to III it immediately shows -1_.__ like it has negative infinite resistance.

EDIT2: Just completed ignition switch test procedure. All appropriate wires show continuity per the test in the FSM.

4drEF

"EDIT: Just found voltage test procedure for resistor box, will do this tomorrow."

How did that work out?

24TEN

iTrader: (2)

No power going to it, resistance between all wires check out.

From the plug side, I have continuity going back to the main relay with key on II, but as soon as I turn the key on III it reads -1_.__ on the multimeter.

24TEN

iTrader: (2)

Bump

4drEF

You won't get a proper resistance test when you apply power.

Check for voltage out directly at the main relay when ignition is on - terminal 3, yell/black wire.
If you get power on that wire, then do another voltage check at the resistor box on the yellow/black wire.

24TEN

iTrader: (2)

Did that with key on II, shows battery voltage at pin 3, no voltage at the plug for the resistor box. I thought there was an open in the wire so I did the resistance test with no power to verify and it showed 2.4k ohms up to key on II. As soon as you go to key on III (cranking) it shows open. That's where I'm stuck.

4drEF

Get a jumper wire the same thickness of the yellow/black wire.
Connect it to the yellow/black at pin 3 on the main relay and connect it up at the yellow/black at resistor box.

24TEN

iTrader: (2)

Manual bypass? I'll give it a shot.

4drEF

Yup! manual bypass.
One last thing though -
Disconnect the resistor box and disconnect the main relay.
Do a resistance check from either end of the yellow/black wire to chassis.
Just to make sure you don't have a short.

No short and I guess you could just run directly to the yellow/black at the resistor box going directly from (+) battery rather than going from pin 3.

24TEN

iTrader: (2)

Thanks for the tip, I'll post up results as soon as I get a chance to do this.

24TEN

iTrader: (2)

Just updating this post. I finally had a chance to work on the car for longer than 30 minutes. Did the bypass, still no start but I could definitely smell fuel. Swapped distributors and it fired right up. I'm going to remove the bypass and if it works in its original wiring setup my guess is that one of the internal sensors in the distributor went bad causing a signal not to be sent to the ECU which in turn didn't allow the fuel injectors to receive power.

EDIT: Confirmed. Removed bypass, car fired up with no issues. Problem lies within the distributor. Thanks to all who helped