Another Car wont start-wierd spark timing...

[mysatilac]

Its a 1990 Honda Accord EX with an internally mounted coil (in the distributer)

It cranks but wont fire
I've been working on this honda for the last two or three weekends, not to mention several other times.

Again Intake and exhaust seem to be operational
We at first thought it was leaking injectors because of the strong gas smell...
Well Now I'm thinking it may be a lack of spark, the battery is a little low (although we've tryed jumping it off)
Replaced the ditributor cap because it was cheap and I wasn't sure if it was good, the distributor does rotate (not the bearings)
I have tested the coil and got the same resistances as a new one.

Used a spark test and got an interesting result. There was no spark while the motor was cranking on any of the spark plug wires, but while the tester was hooked up I noticed I got a spark at where ever the distributor cap was lined up every time the accessories were powered on or off. This is the only time the coil gets power as well...
So I got a spark at #1 when it was at TDC, But only when the key was turned between On (not start) and Off or vice versa. So this doesn't contribute to starting...

I now suspect the Igniter/ Ignition Control Module... would/could this cause the coil to only be charged at these times?
Voltage at the igniter is slightly below battery voltage which is what is listed as correct.
I cant figure out how to check the continuity between wires and the ECU... is there an ECU wire I need to connect to?

What COULD cause me to NOT get a spark only when the engine is cranking?
I also thought perhaps its that the starter motor is draining all of the battery's power not allowing for a spark, but why?

Help me get this car running PLEASE!

[jeffcoslacker]

I've seen the ignition switch go bad on some of these and do this. I bet if you release the key very slowly from the start position, you'll find a spot somewhere before it comes to rest in the run position where it will start and run. If so, that's your problem.

[jeffcoslacker]

If not that, it could be whatever passes as a coil pickup in these too. I don't remember what Honda calls it. But if it goes bad, you'll get a single discharge from the coil when the ignition is shut off, but no contiuous spark signal. The coil fires once to discharge when its primary power supply is cut (key off), regardless of signal or not.

[mpumas]

A spark is produced when the ECU grounds a lead that goes to the igniter. So if it is continually grounded, you will get a spark when you turn the key off because you removing voltage to the ignition coil. You could also have an igniter shorted (good possibility) The igniter is an electronic switch in the distributor which detects the ground from the ECU and completes the coil circuit to ground. The ECU can be checked with an ohm meter. Resistence should be high on the yel/grn wire with it disconnected from the igniter and the key on. As you turn the engine over, the resistence should go from high to low as the ECU temporarily grounds the lead. Or with everything hooked up, the voltage on the lead should go from 12 volts go zero as the ECU tells the igniter to fire. Keep us advised on what you find.

[mysatilac]

Jeff- I tried letting off on the key slowly, but with no luck...

Mpumas-
"The ECU can be checked with an ohm meter. Resistence should be high on the yel/grn wire with it disconnected from the igniter and the key on. As you turn the engine over, the resistence should go from high to low as the ECU temporarily grounds the lead. Or with everything hooked up, the voltage on the lead should go from 12 volts go zero as the ECU tells the igniter to fire."

Where do I probe with my Ohm meter for the resistance of the yellow green wire? am I checking the wire to see if it is broken here- Resistance between the two ends of the wire? or how do I hook it up to the ECU?

What does it mean if the ICM is not recieving the proper battery voltage... it was several volts shy of battery voltage, althought it was getting some voltage ICM at ~9V, battery at ~11V? so it did have some voltage...

Man I am confused on this car...

Don't want to just replace the ICM for $80 if its not the problem...But if it is I will gladly replace it

[mpumas]

The ECU is a ground point for the igniter when the spark is to be produced. So hook the ohm meter to the wire and the other lead to ground.

ICM?? What do you mean by ICM?. If you mean the igniter, battery voltage goes through the coil to the igniter. Any voltage drop would be caused by drop through the coil. Are you getting battery voltage at the top of the coil, the blk/yel wire. If not, that voltage comes through the ignition switch and that may be your problem. You can go directly from the battery to the top of the coil and see if that works.

[mysatilac]

ICM = Ignition Control Module... The Proper name for the Igniter,


By the top of the coil what do you mean?
jumper a wire to the primary + of the coil from the + of the battery?

At this point I'm no longer able to go read voltages at the car, I left town...but will go back down there in a few weeks

I got similar voltage at the coil and ICM of about 8V while the battery was at about 11 V ( I know it was low, could this cause the problem?)
Although we did try jumping it off.

But you're saying that this would cause the problem of only getting spark at the turn of the key where it would charge/discharge the coil? (turning the key from off to on and on to off)

[mpumas]

When the key is on, the wire that goes to the + terminal on the coil should be battery voltage. If OK, hook up and disconnect wire from coil to igniter. Read voltage. If not battery voltage, the drop is either the ignition switch or the igniter. There should be no drop unless the ECU is telling the igniter to fire. The distributor needs at least 10 volts to work. Turning the key on and off is simulating the ECU/igniter firing.

[mysatilac]

niether one was at the same voltage as the battery, they were recieving close but not the same as battery voltage

with neither one at correct voltage Does this mean that it is the ignition switch as you said? (supposedly replaced 3 times previously)

And This did not work (a test for ignition switch?)

Posted by jeffcoslacker - 03-20-2005 at 05:03 AM
I've seen the ignition switch go bad on some of these and do this. I bet if you release the key very slowly from the start position, you'll find a spot somewhere before it comes to rest in the run position where it will start and run. If so, that's your problem.

Also,

Posted by mpumas - 03-21-2005 at 07:41 PM
When the key is on, the wire that goes to the + terminal on the coil should be battery voltage. If OK, hook up and disconnect wire from coil to igniter. Read voltage. If not battery voltage, the drop is either the ignition switch or the igniter. There should be no drop unless the ECU is telling the igniter to fire. The distributor needs at least 10 volts to work. Turning the key on and off is simulating the ECU/igniter firing.

According to your post even if the igniter were not recieving voltage, the coil still could be... "If OK"-the coil voltage, wouldn't the coil be at low voltage if the igniter or the ignition switch were bad

i'm about ready to replace the Igniter and then try the ignition switch if it wont fire after that
But thats $80 into a non-returnable part, so I want to be sure if I can be

Thanks You for your help, I would love to get this car running because my friend is going to be moving soon where it is no longer practical to walk to work...

[mpumas]

If tbe igniter is shorted, then the low resistence in the distributor circuit could make an otherwise good looking ignition switch be bad because of the voltage drop through the switch. There should be minimual voltage drop through the switch with everything operating normally. The igniter receives voltage through two routes one from the coil and the other through the blk/yel. When the ECU tells the igniter to fire, it essentially grounds the wire the wire that goes to the coil. If in doing so, the voltage going to the coil drops well below battery voltage, there won't be enough to cause a good spark out of the secondary of the coil. I can understand your concern about not buying something that is not needed. We try to set up test procedures that will minimize any extra expenses. As you say the ignition switch has been replaced many times, and the igniter not, I would suspect the igniter. Also it is cheaper then an ignition switch. Keep us advised of your sucessfull fix.

[mysatilac]

Ok I'm headed back down to Austin to work on this poor girl's car. i could really use some advice.

Does anyone else agree that this is a bad Igniter/ ICM? Or is there a problem that I'm not seeing here.(mpumas) is there an easy test procedure for the Igniter?

anyone know what honda calls a coil pickup (jeffcoslacker)

it was suggested that the CRANK sensor might be at fault here and to test with a noid light to make sure that the injectors were firing properly to rule that sensor out. (sierrap615)

Also there was a recall in '93 on Accord distributors, but I need to go check the VIN (the motor has been swapped/overhauled), and I'm not sure if it has a new distributor or not.

Again PLEASE help me get this car running!

[mpumas]

To test the igniter, disconnect the distributor coil and connect a light to the wires. The 12 v light should be something like a tail light or of the same cp. Turn the engine over and the light should blink. If it doesn't and you have good voltage at positive side of the coil, then it is the igniter, or ECU or the wiring between the two.
The coil pickups are the TDC sensor, Crank angle sensor and cyl. sensor. If they go bad, you replace the whole distributor.
There was a recall of the 90 Accord distributor also.

Troubleshooting the Honda electrical problems can be a real task. Systems are inter related and to be sucessful, you need a plan to eliminate good parts and find the bad ones. To just replace on a hit and miss basis will bankrupt you. Also you may not gain much on electrical parts from junkyards as they may be defective. Good luck.

[mysatilac]

Thanks For All the Great Help mpumas,

i tried the test, the light didn't come on, but then when I tried to test it through battery voltage, i touched my wires together and burned the bulb out...

So...I took out the ICM and got it tested, then replaced at AutoZone.

Thankfully it turns out this was the problem and the car fired right up with the new igniter.

When I fixed it, I think I was about as happy as the girl whos car it is
She had been without a car for about four months, needless to say even though she has a problem finding parking there in Austin, Its better than walking!

[AccordCodger]

Glad it's all fixed, man. I'm a bit mystified how you managed to burn out a 12v bulb with (12v) battery voltage, though.

[mysatilac]

Thanks,
I would've felt like a dumbass if it wasn't fixed on this (my third) trip down there,

This is long which is why I just posted the short version, but for clarification

I used the battery to test how the bulb was wired, outer part of the bulb was neg, the two bottom contacts were positive.

After the bulb did not work in the test mentioned by mpumas-wire the bulb in place of the coil (may be where it got burned out)

I tried to test it again using the battery, didn't work, thought maybe I forgot how it was wired, so I accidently wired up the 2 postives as + - and fried my wire (like 22 ga. bat. smoked it in like half a second I gotta good laugh and thankfully no shock ) when I checked the bulb it was burned out.

So I'm not sure when I actually burned it out, just that it was burned out after the test for ICM and the 2nd battery test
I really think that the bulb was burned out before the second battery test, but not sure when.

I also dropped the bulb twice, could've busted the filament at that point,
but I didn't exactly burn it out just running battery voltage through it correctly