Mystery No Start -- Please Help

My 1990 Honda Civic 1.5 cranks but will not start. 134k miles. No trouble codes on ECU. ECU does give the 1-blink ?hello? signal. Fuses appear good. Decided to replace starter, which was original. No difference. Battery is good. Attempted to start during jump to our van -- no difference. Main relay clicks as it should (once at key to start, once after check engine light goes off two seconds later, once on cranking). Fuel pump whirring noise can be heard with key to start position (good). With cover to intake removed, could see and smell fuel entering chamber. Starter fluid tried ? no effect. I suspected ignition might be the problem. Distributor cap, rotor, spark plug wires, and plugs were all replaced. Didn?t help. Doesn?t seem to be getting spark. Couldn?t get spark from grounded plug attached to wire. I measured resistance for both primary and secondary in ignition coil -- both were within specs. Wires going to ignition coil are receiving battery voltage. Resistances for TDC and Crank sensors (within distributor) tested good (Codes 4 and 8). Ignition output signal (code 15) also checked out fine. Distributor was removed and rotor shaft does turn freely. You can see rotor turn while cranking engine. So timing belt is not broken. I suspected the igniter (only thing left in distributor) might be the problem, so I replaced this. No help (and $70, non-returnable). Anybody have any idea what might be causing this?

Reply to
sprog
Loading thread data ...

Probably the ignitor or whatever drives it. Make sure you see 12V on one side of the coil first (common to both primary and secondary). Also make sure that you measure a low resistance across the primary of the coil. You'll see a higher resistance across the primary of the coil.

Electrically, the ignitor switches the primary of the coil to ground periodically. To test, you could put a small low current 12V bulb (so we're not talking about a headlight or tail light - just a radio shack 12V bulb) between the +12V and the output of the ignitor. (envision hooking it up across the coil but taking the coil out of the circuit).

If the bulb flashes when cranking, your ignitor is ok. If not, it will take a little detective work to make sure that you indeed are getting a periodic input on the ignitor.

Probably 9 times out of 10, your ignitor is bad, though.

Remco

Reply to
Remco

Oops -- sorry misunderstood that you had already replaced the ignitor. Just noticed it after re-reading your post.

Still the method does apply: the bulb would tell you if you are getting some sort of periodic input to the ignitor and trace it back from there.

Reply to
Remco

"sprog" wrote

No spark, despite replacing all these parts and, ISTM, doing a pretty thorough job of covering all your bases.

I would check the ignitor (even though it's new) per various tests you can do from the manual or with others' suggestions here and elsewhere.

Then I would start changing out old parts with the new, one by one, to see if maybe one of the new parts is defective. Also at this time, double check that you have everything connected correctly.

If everything still checks out, and you still have no spark, I'd be looking at replacing the distributor housing or ECU. The housing mostly to start fresh. A new one every dozen years is not a bad idea, given all the problems it can give.

You gotta get that spark back. The cause shouldn't be too hard to identify.

Elle Original owner, 91 Civic. On 2nd Distributor housing, 3rd igniter, 3rd coil. Didn't use OEM always. Big mistake. Use OEM. Car runs like a charm. 40+ mpg. No oil leaks (though I've been changing the major seals in the last year or so).

Reply to
Elle

You have done some very good work so far. I had a similar problem with a

95 Civic after doing a valve adjustment. By just cranking it just a few turns in my driveway with the secondary of the coil disconnected, I fried the coil and ignitor. You should always disconnect the primary of the coil or ground the high voltage secondary before cranking. Otherwise the high voltage creates its own path through the coil shorting it out internally. It seems it's not unusual for a coil and ignitor to go out together as confirmed to me, after the fact, by a dealer and an independent shop. I did not believe my coil could be bad too, but when I checked it out again with a high quality ohm meter, it was just outside the spec limits. If not the coil, I would be looking at that main relay regardless of clicks, then lastly the ECU. Good luck.
Reply to
duckbill

Duckbill actually has a very good point, about the coil:

On my wife's integra, the coil measured fine, but had discolorations along where it was close to the bracket. It was actually rough in spots, not smooth as one would expect a molded part to look like. I suspect that it may have arced through in those places.

Reply to
Remco

Seconded - an ohmeter won't tell you if high voltage is arcing through (unless you have an ohmeter that tests at 50kV).

Also, duckbill may have a point on the main relay: the clicking shows that the solenoid of the relay is working fine, but the switched contacts may be no good.

Reply to
Matt Ion

This part of Tegger's FAQ seems appropriate:

formatting link
Note Mike's comment that the coil "zap spot" is barely noticeable in ordinary lighting.

Click on "back to top" of this site to see more discussion of this.

I would think such a coil failure would show up on a resistance check of the coil. Sprog, did you do the manual's resistance check of the coil? There are actually three.

Reply to
Elle

"Elle" wrote in news:Ot6af.4843$ snipped-for-privacy@newsread2.news.pas.earthlink.net:

Resistance checks on inductors is kinda iffy. For the secondary of an ignition coil,it is usable because of the large number of turns to get the HV,but if turns close to one end short,the resistance change will not be noticeable,but the short will still affect the coil's operation.

Dick Smith Electronics makes a coil ringer for TV flybacks that IMO would be effective in testing an auto ignition coil,although I've never used one or tried it.(same principle;TV flyback and auto ignition coil.)

Reply to
Jim Yanik

Be careful testing a transformer in that type of setup, because the frequency and duty cycle of the TV flyback driver is a lot higher than that of a car. The car's coil may not be able to take it.

Reply to
Remco

"Jim Yanik" wrote

Makes good sense.

Also, I messed up. There are only two prescribed coil resistance tests for the 1990 Civic.

Reply to
Elle

"Remco" wrote in news: snipped-for-privacy@g47g2000cwa.googlegroups.com:

It's based on the "ringing" test for inductors.Pulse it and check for a decaying ringing waveform,so it would not stress the ignition coil.

Here's a link for more info;

formatting link
It only applies 650mv to the coil,so it's not going to hurt an auto ign coil.It counts the number of 'rings' after the pulse,indicates it on a LED bargraph display,and amazingly,only costs $30 AUS dollars(kit form). I've not built or used one,so I can't say for certain it would work,but his ESR meter was an easy build and WELL worth the money.

Reply to
Jim Yanik

Clever!

When I lived in Europe I had access to Dick Smith kits. They had some cool gadgets on could build, even then. Haven't seen them here in the US :(

Reply to
Remco

Sounds like a winner! I have used a Sencore "Z meter" that also had a ringing test and it was one of my favorite features. You get an answer you can really hang your hat on. Nice to see it in a $30 AUS device instead of a $1000 US device.

Mike

Reply to
Michael Pardee

"" wrote: > You have done some very good work so far. I had a similar > problem with a > 95 Civic after doing a valve adjustment. By just cranking it > just a few > turns in my driveway with the secondary of the coil > disconnected, I fried > the coil and ignitor. You should always disconnect the > primary of the > coil or ground the high voltage secondary before cranking. > Otherwise the > high voltage creates its own path through the coil shorting it > out > internally. It seems it's not unusual for a coil and ignitor > to go out > together as confirmed to me, after the fact, by a dealer and > an > independent shop. I did not believe my coil could be bad too, > but when I > checked it out again with a high quality ohm meter, it was > just outside > the spec limits. If not the coil, I would be looking at that > main relay > regardless of clicks, then lastly the ECU. Good luck.

UPDATE ? O.k. Here?s the latest on my ?no spark? situation. I?m still not getting spark at a grounded plug, with new distributor cap, and new wires.

I did the following test. I took the cap off and ran a length of heavy 12 gauge Romex house wiring from the secondary tower of the coil to body ground. I got spark on cranking! Good, but the question now is: why is this spark not going through the cap and down the wires. I checked for continuity in the cap and rotor (both new) and they were fine. I then decided to crank engine (in the dark) to see if the coil itself was arcing. Nothing was visible externally but as I looked down into the secondary terminal itself, into the tower where spark would enter the cap if the cap were attached, there was all kinds of arcing going on in there. You may remember the old Batman TV shows, when the Batmobile was pealing out of the Batcave, all the flames coming out the rear end of the car. It kind of reminded me of that. Now I don?t think there should be arcing going on within the secondary terminal itself, right? I removed the coil and did a close inspection of the inside of the secondary tower. The insulation appears pitted. So the coil is shorting out under high voltage because the insulation has been compromised. Yet the darn thing still tests good because my multimeter isn?t subjecting the coil to voltage high enough to cause the arcing. Primary and secondary resistances are still within specs! So I?ve learned that a coil can test good even if it?s bad. My only question now is whether I caused this coil failure during the repair process by cranking the engine several times without having the secondary grounded OR if this coil arcing was the original problem. The problem did start after a week or so of heavy rain, so I?m hoping that the bad coil is the underlying problem. Thanks for all your suggestions and I will let you all know when I replace the coil whether that did the trick.

Reply to
sprog

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.