Another Car wont start-wierd spark timing...

Another car wont start, :(

OK, I know some of you guys dont like Hondas. But I dont really like the honda forum... And I need a mechanics advice. Its a 1990 Honda Accord with an internally mounted coil

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
I have tested the coil and got the same resistances as a new one.
Used a spark tester 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. So this doesn't help...

I now suspect the Igniter/ Ignition Control Module... would/could this cause the coil to only fire at these times?
Battery 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 though 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!

are you using a inductive tester or fake spark plug type?

some manufactors use a ballast resistor. with the engine running, the coil does not get full voltage, but during cranking, the resistor is bypassed so the coil gets full voltage. - i would need a wiring diagram to confirm or disprove this theory.

also, i don't know how this car got to this point but another off the wall theory is somehow the coil was rewired so its voltage source was somewhere where its shut off when cranking (IE the radio) see if the coil has voltage while cranking

I'm using the fake spark plug type spark tester,

I have a wiring diagram that I'll send you when I get back to a scanner... I actually have 2, I'll look for a resistor listed on them in the morning, where is that normally located?

It doesn't seem like it was mis-wired, the car was running at one point, but has since died like a component has gone out...

Again do you know if the igniter unit (ICM) which I believe controls when the Coil geives spark could be at fault?
It is a strange symptom to be showing, also and its probably related when we have tried cranking he car and stop cranking, it kinda lurches, I'm wondering if this is the spark givin to one cylinder (the one the ditributor cap is lined up with) igniting that cylinder as we turn the key over to off... Seems like last time we did get it started it was by kinda tapping the ignition over to start twice, Like maybe this fired the cylinder and was enough to start it.

I'll check to see if the coil has voltage while cranking although i'm not exactly sure how to test for this since it should be supplying the spark plugs with ~25,000DCV and my multimeter only goes to 1000DCV, thus the use of a spark tester. I tried hooking the coil up through a spark plug wire on the secondary (winding) terminal and thought if it was giving out this voltage it should give a continuous spark

Oh ok i check to see if it is getting battery voltage at its primary + and - terminals not what voltage it is giving out...

Battery is still weak, starter draining it enough to cause a no spark condition?
Maybe sparking at on and off is normal (doubt it)?
gonna try jumping it off again in the morning though, and if I can't get it started then it looks like I'm headed back down here to Austin in a few weeks. I feel bad that I haven't had any luck with this car

We thought we had figured out it was the coil three times now becuase of inaccurite readings of the resistances, but have been disproved by checking against new coils at Auto Zone and O'Reilly's
Also the Austin AutoZone has been nothing but a disapointment-not renting the correct tools as advertized only offering them for sale, and when I asked for a noid light the lady (who seemed like she was the only one who knew what she was talking about) brought us back a test light for circuits 6V, 12V, 24V... and then after asking for a spark tester (Calibrated Ignition Tester) it took asking a third guy to tell us that it was on the shelf, where we stumbled across 3 noid lights. (Hope I don't see that lady again) And going to 2 autozones to get the coil checked on some machine they had at the second store, where we found out they dont have the right adapter for a '90 accord's coil
:(
But I wont let this get me down, I will "gladly" come back down here and make another attempt on the car...

Thank You for the quick thoughts sierrap-hoped you'd be posting tonight, :)

Dear god i love DIS.

check battery voltage while cranking. (below 9.6 is bad)

i'm not sure what a bad ICM would do. i would like to see a wiring diagram if possible

check your paperwork, see if there is a way to enter "base timing mode"

did the noid light blink?

sorry for the lack of definitive answers, distributors are not my strong point. you may also want to post here - http://www.automotiveforums.com/vbulletin/forumdisplay.php?f=670

Checked voltage to the coil... today it was alot less than battery voltage, about 5V, when battery was at about 12V

Battery is still slightly discharged, but I've left Austin and I'm back at home again, I'll probably go back down there in a few weeks and would like to have something new to try...

What does that low battery voltage to the coil mean exactly, I believe this voltage comes from the PCM/ECU

Never hooked up the noid light, because we weren't getting a spark I figured this was our problem, no longer the injectors...

What does that low battery voltage to the coil mean exactly, I believe this voltage comes from the PCM/ECU



the power is going some where else instead, chances are, this this means you have high resistance in the circuit somewhere. if you have a ballast resistor this is to be expected, but even then 5volts doesn't sound quite right, unless its a VRef(5 voltage referance signal from PCM). but if it is suppost to be geting 12 volts-

basic electrics 101 - power from terminal to terminal of the battery is also known as source voltage. all voltage is used in a circuit. hence if you are puting out 12 volts, 12 volts is being used. the power used for one compontent, measured from the + side to the - side is also known as that component's voltage drop. so if your source voltage is 12 volts, and the voltage drop of the coil is 5 volts, the other 7 volts are also being used somewhere else. (again i would need to see a wiring diagram to guess where the drop is, but i know they are on the way) in the mean time, try to find where the other 7 volts are going. test the voltage drops of the wires, measure voltage from + battery to + coil and from - battery to - coil. after you have those number, refer to the wiring diagram and determine what areas are possibly at fault, and if possible, keep checking voltage drops of wires and compontents until you find the exact problem(or as close as you can get) also remember you need a compete working circuit to test voltage, meaning backprobing may be nessacary(thats another how-to for later)

also, are you using a digital or analog multimeter? if you are testing and circuit connected to the PCM, do not use a analog meter.

I think the only thing that is in between the ECU and the Coil is the ICM (igniter)
So again I may decide to blame this component...
But with low battery voltage, would the ECU be sending the wrong voltage to the coil?

Or do these guys make more sense to you?

Posted by Mpumas (Honda Forum)

"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 to zero as the ECU tells the igniter to fire. Keep us advised on what you find."

(Where would I probe the yellow/green wire for OHMs? Both sides of the wire?)
(The voltage should drop to zero when the ECU tells the igniter to fire? Because the coil takes the 12V?)

Posted by jeffcoslacker - 03-20-2005 at 05:07 AM
"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."

(Is the coil Pickup the ICM on these hondas?)

ok, got the diagram.

what is fuse 4 labeled as?
do you have another name listed for PCM terminal A21 or A22?
when exactly can you get spark?
plug in the Noid light, i want to know if you get anything.

the voltage droping 12 to zero is the backprobing thing.you need a closed circuit to truely measure voltage. if you measure a open circuit, you will most get source voltage, the ECM controls the ground(by opening and closeing the circuit). since we are measuring after the load, 12 volts means a open circiut and 0 volts means a closed circuit.

at this point i'm leaning toward the CPS, ICM, or a sight possiblty of the ECM.

see if the injectors are firing if not the CPS may be bad, if they are, try the test the honda guys gave you.

Fuse #4 is not labled as anything in the fuse box... barely sqeezed in the 4...

A21 and A22 are only labled as IGP1 and IGP2, but that is also in one of the two diagrams that I sent you

I get a spark when the engine is not cranking... just when the key is turned to the on or turned to the off position where ever the distributor cap is lined up to, when the coil is charged/discharged

I figured that they were firing since I was getting so much of a fuel smell, origially thought that they were leaking... But I will check with a noid light next time I'm down there (probably 2 weeks)

Yeah I got the backprobing thing, use the probes to check while the wires are plugged in...
Ok thanks for clearing up the after the load voltage thing,

BTW, not sure since Im no longer at the car, but I think they used 75A fuses in place of the 7.5A fuses (maybe not) including on #4, would this provide enough resistance to screw me up, or just short something else out when the fuse should have blown?

Sorry, what is the CPS?

I'm a bit (read bit as "way") out of my league here, but i was about to say, "hey, isn't there some kind of relay that allows voltage to go to the coil? that would be my guess"

But in reading the descriptions up there, the igniter seems like it "is" that relay. Which would make me agree that is the problem. I've never had to fool around with one of those though...

edit: oh, 'bout the fuses, bigger gague fuse wont (shouldn't) add any resistance, but it sure could fry some wires.

edit: oh, 'bout the fuses, bigger gague fuse wont (shouldn't) add any resistance, but it sure could fry some wires.


Thanks, thats what I thought, but also thought I should ask incase I was wrong... If they are the wrong Amperage, I will change them out next time I'm there. So I dont fry anything... I'm thinking maybe he kept blowing fuses at 7.5A and went to 75A (bad idea), which would just fry something else instead of the fuse...

I now susepect either the Igniter or the Ignition switch, although I would like to see if the injectors are firing to get sierrap's conclusion about the CPS (still not sure what that is though)

CPS - crankshaft position sensor, both the injectors and the spark timing depend on it.

that 75 amp fuse may just be a 7.5 amp with out the dot. if its a mini fuse, i can granutee it. the wire inside the fuse would be about ten times larger. just look and you'll see what i mean.

is it a manual transmission?

i'm think of a few other tests, but i want to do a little research myself on ALLDATA before i list them.

its an auto tranny, tried starting it in nuetral and park...

Thanks, thats what i though CPS stood for, and would have known but on these Hondas it is just called the CRANK sensor (crank angle sensor) (w/in the distributor-checked out with proper resistance)

Not a mini-fuse, just a normal size blade style
Yeah I know exactly what you mean about the relative fuse wire size, but like I said I'm no longer there to look...

Think I'm gonig to change out the ICM if the injectors are firing
Thanks (as always) for the tips!

Hey,

The problem sure sounds to me like a ground is either missing or you have a ground somewhere where it shouldn't be. As to where to find that, whoo...you got me. My first guess would be in the ignition switch, but I know they can be costly to just up and replace, and I haven't the faintest idea of how to check for a missing/shorted ground there. Just my two cents.

Sorry if thats redundant or not much help at all,

phattyc75

Thanks, always glad to have another person's opinion on the whole thing,
yes, that has been mentioned but not explored. I may go to a junk yard and pull both an ignition switch and an ignition control module (if I can find them).
But that is after I check to see if the injectors are firing (although I believe that they are since I smell fuel so badly, though I supposed they/one could be stuck in the firing position due to a bad CRANK sensor...)

My mechanic mentioned that the distributor bearings on these go bad alot of the time causing an oil leak which causes these sensors to go bad, so it is a good posibility

found sometime today - a recall from 1993. it says the distributor may fail causing a no start. an updated assembly was released. have your friend check the VIN plane for a center-punch mark above the last digit of the VIN. that punch is the completion mark, if its not there, you have the old bad design.

So, then could I send it in, as a recall-free of charge? :):):)

you will have to ask honda, i don't know if they will honor a 12-year old warrenty claim. the bulletin number is 93-032

:( I'll have to call and get the VIN # from my buddy, and see if there is a mark above the VIN *hope not*

But thank you very much for the info even if they can't help, it narrows down the problem

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

I had my buddy check the VIN, he says its right behind the inspection sticker and can barely see it, but doesn't think that there is a mark.
But the car has had the engine overhauled/swapped... will there still be a mark, or a new distributer?

Is there an easy test for the ICM/Igniter?

I'll try the noid light for the CRANK sensor as soon as I get there...

Always glad to get new opinions/confirmations!

Again, PLEASE help me get this car running!

But the car has had the engine overhauled/swapped...

that changes things, depending if it was rebuilt or swap,if it was swaped then with what year, when it was done, who did it, ect, ect..... they may have used the old distribor or put in a different used one or put in a new one. check the service records if you can (as i bet they would have charged you), failing that, see if you can be lucky enought to spot a date stamp. otherwise, pick up a junkyard one for cheap to test(or buy a new one from honda)

Thanks For All the Great Help Sierrap,

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!