OCwrencher

Main symptom is after starting the car, it will idle fine. Shut it off and come back in a few minutes, no start. Plugs are wet and I am concluding it won't start after it's running with weak spark and loading up on fuel and after it's shut off, the spark is too weak to ignite the rich fuel mixture. When it does fire back up, after sitting for a while, exhaust smells like gas. Also, the car has bad hesitation issues while driving, it's parked now though.

Has weak/missing spark. This is the only conclusive problem I can find, but can't find the problem causing it. No CEL codes, verified with scan tool.

It's a D16Y7 (96 LX) 240k miles. Having trouble chasing it down over the past few weeks.

The down low on what has been done:

-stock fuel psi numbers and fuel psi reg. checked
-close to stock compression numbers (between 178-186 across the board)
-verified injectors pulsing correctly (also just had them ultra-sonically cleaned and flow-benched)
-ignition switch checked out (even bypassed it completely, and still symptomatic)
-PGM-FI relay checked and re-soldered (was good to begin with but did it for preventative maintenance)
-plug wires tested good, even swapped in a new set in case
-distributor has been replaced with new
-tested and tried 3 different coils (all testing good to begin with)
-tried 2 ICMs (both verified by AutoZone)
-checked continuity for the distributor Hall Effect sensors to the ECM and they're good
-swapped in another computer and still same weak/missing spark
-replaced CKF sensor
-timing is set correctly at 12*
-all engine sensors have 5V reference
-battery terminals are clean with good connections
-grounds verified including the thermostat housing ground, and remade a few grounds with bigger copper wire and copper terminals, even ground the paint down and liquid electrical taped over the connections to chassis
-new plugs, stock NGK replacements, gap @ 1.1mm
-replaced ECT sensor
-IACV cleaned and tested
-MAP, IAC, TPS all verified 5V reference and correct output readings to OE spec
-New Honda cap and rotor

Problem started before I did any of the things above, so anything that's listed above is NOT a cause.

No mechanical problems at all. Car is in good repair. Any help would be awesome. I am pretty knowledgeable with a good tech background and this is giving me a run for my money. I have even stumped friends/colleagues with good tech experience and they have no clue either.

Former User

Let's start with the basics.

Any CEL codes?

When the engine won't start:
1) What battery voltage do you measure?
2) What voltage do you measure at the Blk/Yel wire attached to the coil with the key in ON(II)?
3) Is spark bright white at all 4 spark plugs?

OCwrencher

Edit to my first post. I made a mistake writing down the wire color.

No CEL codes, verified with my scan tool.

When the engine won't start and when it will (readings don't change)
(1) ~12.65V at the battery
(2) ignition on, not running ~12.30V on distributor side of connector and harness side also
(3) No, it's weak (yellow/orange, blue at base of the spark) link to spark plug test video below

http://youtu.be/O7Bs5n1fPiU

And if you really want to know here is the results from most of the tests I've done.

-Battery:
Ignition off= 12.65V
Idle & no accys.= 14.45V
Idle & h-lights= 14.35V
Idle & all accys.= 14.27V
Static engine off after idling= 13.43V

-Tests: At Idle and Operating Temperature
ECM Connectors:
• D connector 16P, terminal=(D**)
• C connector 31P, terminal=(C**)
o MAP: at sensor with terminals connected
(D3) Red/Grn= 0.87V to ECM
(D12) Grn/Wht= 1Ω to ground
(D?) Yel/Red= 5.0V from ECM
o TPS: at sensor with terminals connected w/ TB closed
(D11) Grn/Blk= 1Ω to ground
(D?) Red/Blk= 0.5V to ECM
(D10) Yel/Blu= 5.0V from ECM
o Distributor:
Blk/Yel= 14.27V
o Injectors:
Blk/Yel= 14.30V

-Distributor Housing Sensors: Engine off/ Ignition off (350-700Ω @68*F)
o Crankshaft Position Sensor (CKP)
o Top Dead Center Sensor (TDC)
o Cylinder Position Sensor (CYP)
o CKP:
(C2)2 Blu: 1: 417Ω
(C12)6 Wht: 2: 400Ω
o TDC:
(C3)3 Grn: 1: 421Ω
(C13)7 Red: 2: 404Ω
o CYP:
(C4)4 Yel: 1: 417Ω
(C14)8 Blk: 2: 401Ω
o Legend- Resistance across each sensor’s corresponding wires:
o 1: At distributor connector, disconnected from main harness
o 2: At ECM connector, disconnected from ECM, connected at distributor


-PGM-FI Relay:
o Bench tested using a 12VDC battery (measured at 12.37V)
o Resistance across terminals after relay is energized:

o Before re-solder:
Relay #1: Injectors
• Terminal energized= Terminal measured/resistance:
#5 = Pos+ #6 1.8Ω
#3 = Neg- #7
Relay #2: Fuel Pump
• Terminal energized= Terminal measured/resistance:
#6 = Pos+ #4 0.4Ω
#1 = Neg- #5

o After re-solder:
Relay #1: Injectors
• Terminal energized= Terminal measured/resistance:
#5 = Pos+ #6 0.00Ω
#3 = Neg- #7
Relay #2: Fuel Pump
• Terminal energized= Terminal measured/resistance:
#6 = Pos+ #4 0.00Ω
#1 = Neg- #5

-Coils: Tested off vehicle

o Primary= A(+) and B(+) 0.63-0.77Ω @68*F
o Secondary= A(+) and Secondary terminal 12.8-19.2k Ω @68*F
Tec (original)
o Primary= 0.7 Ω @54*F, 0.7 Ω @71*F
o Secondary= 15.93k Ω @54*F, 16.27k Ω @71*F
Cardone Distributor coil (new not reman)
o Primary= 0.7 Ω @54*F, 0.8 Ω @71*F
o Secondary= 16.01k Ω @54*F, 16.18k Ω @71*F
BWD (new)
o Primary= 0.7 Ω @54*F, 0.9 Ω @67*F
o Secondary= 15.67k Ω @54*F, 15.49k Ω @67*F

-Plug Wires: 25k Ω max @68*F

Cylinder # (4) (3) (2) (1)
o Super Mag (Old):
@47*(k Ω) 0.86 0.90 1.10 1.21
o NGK (New):
@47*(k Ω) 3.47 4.10 5.12 5.79
o Xact (New):
@50*(k Ω) 6.23 6.27 7.84 8.66


-Injector Flow After Professional Cleaning: cc/min @43.5psi

o Cylinder # (4) (3) (2) (1)
189 190 186 188

-Fuel Pressure Test: Operating Temperature

o Static: 44 psi
o Idle: 36 psi
o Fuel Pres. Reg. vacuum hose disconnected: 46 psi

-Compression Test: 250 rpm and wide open throttle (before and after cylinder head rebuild and head gasket, all Honda parts, 0.012” machined off head)

o Cylinder # (4) (3) (2) (1)
o Initial: 197 176 184 176
o After: 167 157 160 164
o After 2k miles: 192 187 179 187

Nominal: 184 psi
Minimum: 135 psi
Maximum Variation: 28 psi (~15%)

OCwrencher

Anybody got any better troubleshooting ideas?

Former User

Spark seems erratic and off colored. Is it the same at all 4 spark plugs?

My first concern is the aftermarket distributors. Your best bet is OEM. It's more expensive but worth every penny.

OCwrencher

Same at all the plugs. I definitely agree about OE parts. I didn't suspect the distributor to begin with and didn't want to drop the bones on Honda one just yet. Got the Cardone unit for about $100 new and it is servicing it diagnostic purpose. For the record I used all Honda parts when I did a head gasket, timing belt, water pump, rad hoses, etc. and normally do on everything else. Only Honda oil/air/fuel filters go on it (and HondaBond is in my toolbox), that will give you an idea of how I service my stuff I think the distributor, plug wires, and ECT are the only non-OE parts on the motor.

Same symptoms before the distributor as after, only difference is that it seems to be getting progressively worse (weaker spark and it used to only start having issues after it warmed up and now it does it upon start-up), but not right after the distributor was installed either. The spark is just getting weaker. I wish I had access to a scope so I could see the spark. I don't have another Civic to compare to, just what the Honda FSM has to reference.

What do you think of this?

This was the new Honda rotor I installed towards the beginning of diagnostics of the problem. A new coil was also installed at the same time. This is after less than 200 miles around town and idling in the driveway, during diagnostics



This is the one I pulled off at the very beginning of the first signs of the issue.

Former User

Our Civics don't do well at all on non-OEM distributors.

OCwrencher

I hear ya, I am just finding a hard time believing that it would be so bad that it would cause the spark to be so weak that the engine floods and won't restart minutes after shut off.

So say I replaced it with an OE unit, and it was still symptomatic. What would you think then? Anything I am overlooking other than part brand?

Former User

Your distributor seems to be getting proper voltage. What are you using for ground in your voltage tests? Have you cleaned and tightened the grounds on the thermostat housing, from the transmission to frame, and from frame to (-) battery?

Otherwise, the quality of spark is determined by components inside the distributor. The ECU tells the distributor when to spark but plays no role in spark strength.

Oh, and are the spark plugs properly gapped?

Former User

OCwrencher

I use the battery negative terminal and the thermostat housing. I have cleaned ALL the grounds, at the thermostat, trans to frame rail, radiator support to power steering cylinder head bracket.

Thanks for the diagrams but I already have all that in my Honda FSM.

Here is a shot of the new grounds I made up.





Spark plugs gaped @ 1.1mm (0.43in)

I guess I am going to re-install my OE distributor and swap the new ICM and coil in it, and see what change there is, if any. Thanks for the help so far.

motegicivic

I assume the distributor is under warranty, I would swap it out.

As for weak spark the coil can also be the culprit, I would swap it out as well under warranty.

OCwrencher

I am getting to that I think. I guess failure rate is high.

So now I finally got CEL codes....P0302, P0304, P1300. I know what they mean, cylinder 2 & 4 misfire and Manufacturer control ignition system or misfire (multiple misfire). Question is that I have a new distributor on it (got it that it's not OE but it's new and not reman), new plug wires, new OE NGK plugs gaped @1.1mm and all my grounds are good. Had the ICM in the new distributor tested by AutoZone and it passed three times. Have correct voltage at the distributor. New coil has tested good but I am still getting really weak erratic spark. I am putting the OE distributor back in with another new (different) coil, the new ICM, Honda cap and rotor, and see what I get. If it's better or I get a change, I guess I am going to swap out the distributor under warranty.

Any other troubleshooting ideas?

motegicivic

Swap it for sanity sake.

I had a new aftermarket MAP sensor bad out of the box, so aftermarket parts can be bad off the bat.

Swap the distributor first, then the coil.

OCwrencher

I've never ran into bad parts right out of the box before, as far as electronics go, but seen and heard of it plenty. Probably because I usually strive for the better, usually more expensive parts, if they're not available OE. I went for the aftermarket distributor for cost purposes at the time.

Yeah I know about the sanity thing This specific problem has been testing my troubleshooting experience/patience to the max.

OCwrencher

Forgot to mention I was going to swap the OE distributor housing and various new parts back in because I already have them.

If I don't get a change from this, I am going to return the distributor as defective and swap it out from a new one. If I still don't get a change, I am going to disconnect my alternator charge wire to the battery and test the alternator for AC voltage/amperage output because I know if it's getting ready to go see Jesus and the diode pack is failing, it will do all kinds of weird crap to the electrical system. I haven't tested the alternator in the car yet because it's kind of a pain to get to, but that's next.

OCwrencher

Update:

Swapped out the replacement distributor under warranty for another new one and no change to the erratic spark. The spark seems stronger (White/Blue) compared to the original OE stuff that was in it, but the spark is stilling missing randomly on all cylinders. At one point I was able to get some misfire codes, but it hasn't reproduced the codes again while it's been sitting, while I've been working on it, and it's pretty much just idled and not been driven.

I've replaced the whole ignition system to include the CKF sensor and tested all the connections to and from the computer, and they're all within Honda resistance specs.

I am very confident in my wrenching skills and this problem is taking me to my wits end. Any ideas/suggestions?

motegicivic

Have you tested your charging system?

All grounds are clean and intact right?

Former User

Have you measured the resistance of the Yel/Grn wire running from the ICM to the ECU and tested it for a short? If that's fine, try swapping in a known good ECU.

OCwrencher

Alternator was replaced just recently and was tested before it left the store. All grounds were redone with new wire and copper terminals.

Speaking of charging system though, new piece to the puzzle today. The charging system indicator light (battery) flickered at me for a short while today when test driving it. Couldn't get it to do it again later though, and after it sat for a while, I tested the battery voltage which was 13V. Overcharge situation there, but while idling it stayed at 14.3V which is normal. More investigating to come on that. Going to check for shorts in the alternator wiring.

I have swapped in a known good ECM but no change. Come to think of it, I don't think I tested the Yel/Grn wire's resistance between the distributor connector and the ECM. I'll do that tomorrow along with my charging system tests.

turbomikeg88

have you figured this out yet? im having the same problem and i have replaced and tested the same components you have and still have that erratic weak spark and the car dies and does not want to start unless i let it sit for 5-10 minutes and the car fires back up like nothing happened. Really need help with this, so any solution you find will be appreciated , thank you.

Cody Bentley

Me to bro.. i need help too

muellersfan

8 year old thread

Dez203

anyone I have same problem cannot figure out ready to give up on this car! has weak spark random times