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-   -   Lost ignition spark to both leading and trailing sides? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/lost-ignition-spark-both-leading-trailing-sides-749052/)

84stock 04-17-08 09:56 AM

Lost ignition spark to both leading and trailing sides?
 
Alright, last night video run ended up with ride on the tow truck home. :wallbash: Problem, "NO SPARK". So after trying all I knew, I searched, and here is what I have found and done. Changed ignitors, changed distributor (in case of pick up failure), changed distributor rotor (Doc's thread), tested engine fuse (fuse panel under dash), swapped out (over and over) top 2 fusible links, tested "all" 5 fusible links (test light and battery), tested for voltage (via test light) to coils, with the cable grounded my probe lights up on all 4 coil posts (???), tested the distributor power (black wire) (via test light), grounded the clip and probe lit up no problem. All this and still no FU^&ING spark. Any more suggestions pleaaaaaaaaaaase!!!! :wallbash: :wallbash: :wallbash:

gsl-se addict 04-17-08 10:14 AM

Is it both leaing and trailing that have no spark?

You ae getting power to the coils (test light lights on all 4 posts). Sounds like you are getting power to the ignitors too. When the key is on, but the car is not running, you should have 12v at the + and - on each coil and should have 12v on both pins of each ignitor.

If that checks out, you could do a continuity test between the ignitors and coil. Turn igniton switch off. Resistance should be about 0 between both coil + terminals and also between a coil + and either black wire to the ignitors. Then check the YG wire (between ignitor and corresponding coil). Then check YL wire.

If you lost spark to both, the only thing that would take out both at once would be a loss of electrical power, but it seems theat you have ruled that out. Could be a bad coil..it doesn't sound like you have tested/replaced the coils yet.

Good luck.

Kent

84stock 04-17-08 10:53 AM

Update, found my voltmeter and I get about 9-9.8 volts at all copil poles. I have some spark (using the coil + spark plug visual test) but even less spark when doing the plug wire + spark plug visual test. So I figures, maybe it is also flooded. Pulled out leading plugs, cranked it over to clear the chambers, added a little 2 stroke oil, 2 nd set of plugs installed (mine weren't soaked or anything though). Same fuck'in deal,:wallbash: :wallbash: :wallbash: :wallbash: :wallbash: . So I tried another distributor cap that I had in the garage, same deal! I give up, gonna snow the next 4 days anyhow. I'll go buy a new cap and rotor today and go from there I guess. :scratch:

84stock 04-17-08 10:56 AM

And as many already know, fesh bridgeport with about 4000 km, so it si good, 3 nice swooshes on each rotor as well when I cleared the chambers (at least that gave me peace of mind). I bought an SE a year ago that was flooded to hell and after deflooding and wiring a fuel cut switch and adding oil in the plug holes she fired up right away.

Jeff20B 04-17-08 12:40 PM

Install a relay to feed full battery or alt power to your ignitors and coils. 9.8 or whatever is WAY TOO LOW!

teddyrx2 04-17-08 12:57 PM

9.8 volts damn i was reading thread then saw 20b's post yeah bro thats way to low...

Did you check the little igniter box on the driver side up near the front just between the battery and the headlight?

84stock 04-17-08 05:24 PM


Originally Posted by teddyrx2 (Post 8103673)
9.8 volts damn i was reading thread then saw 20b's post yeah bro thats way to low...

Did you check the little igniter box on the driver side up near the front just between the battery and the headlight?



Duhhh, ignitor box? Can you be more specific?

Rx-7Doctor 04-17-08 05:52 PM

Do you have a tach signal when you are cranking the engine?

84stock 04-17-08 06:19 PM

yup, bouncy bouncy bouncy

84stock 04-17-08 10:33 PM

Well I got ignition and tach signal, still no go, did a compression test and 90 lbs on the front and 30 on the back:wallbash: :wallbash: :wallbash: :wallbash: :wallbash:

djessence 04-17-08 10:46 PM

What was wrong with the ignition?

84stock 04-17-08 10:51 PM

Hard to pinpoint, once I got it home I swapped out distributors, ignitors, fusible links etc.....

Rx-7Doctor 04-17-08 11:27 PM

You can either put some MMO in the housings and let it sit then recheck compression.

Or after letting it sit with MMO overnight get someone to tow you for a couple of miles with the transmission in 3rd gear. Then recheck the compresssion.









Originally Posted by 84stock (Post 8105704)
Well I got ignition and tach signal, still no go, did a compression test and 90 lbs on the front and 30 on the back:wallbash: :wallbash: :wallbash: :wallbash: :wallbash:


84stock 04-17-08 11:31 PM

At just 30 psi on a fresh motor, it doesn't look promising.....she's gonna have to come out. I am really "REALLY" hopiong my brand new fd housing survived! Good news, just a partial teardown, other good news, builder offered to just charge for parts and donate a rotor if needed, only bad news potential is the housing.....:wallbash: :icon_no2:


Originally Posted by rx7doctor (Post 8105866)
You can either put some MMO in the housings and let it sit then recheck compression.

Or after letting it sit with MMO overnight get someone to tow you for a couple of miles with the transmission in 3rd gear. Then recheck the compresssion.


84stock 04-17-08 11:32 PM

Doc, have you seen many housings survive through this??

djessence 04-18-08 12:05 AM

Can we even get MMO here?
............


Did a google search. Apparently MMO is available from TruServ Canada Retailers which are "True Value" stores. However in their find a location menu, they do not list any for any major city in Alberta. Or BC. Or Manitoba. Kingston in ontario though... Any Western Canada guys have luck getting MMO?

Rx-7Doctor 04-18-08 12:14 AM

Survive through what?

You didn't over rev the engine, you didn't have detonation, you just lost ignition.
When you were doing the compression test, did a lot of fuel come out?

Also you stated that you had 3 nice swooshes on each rotor ?

I still say tow the vehicle and recheck the compression.








Originally Posted by 84stock (Post 8105878)
Doc, have you seen many housings survive through this??


bliffle 04-18-08 08:59 PM

Maybe your primary voltage to the coils is low. I just measured mine at:

coil voltages while running:
firewall side screw post: 13.6 v. (Leading and trailing coils)
radiator side screw post: 12.5 v. (Leading and trailing coils)

This is a stock 85SE with 170k that starts instantly and runs smoothly.

Did you clean the battery posts and cable clamps?

84stock 04-19-08 12:19 PM


Originally Posted by bliffle (Post 8108853)
Maybe your primary voltage to the coils is low. I just measured mine at:

coil voltages while running:
firewall side screw post: 13.6 v. (Leading and trailing coils)
radiator side screw post: 12.5 v. (Leading and trailing coils)

This is a stock 85SE with 170k that starts instantly and runs smoothly.

Did you clean the battery posts and cable clamps?

Read above, solved the ignition issue to find lost compression in my second rotor..:icon_no2:

Jeff20B 04-19-08 07:53 PM

How soon before you can tear it down and see how it lost compression?

bliffle 04-19-08 11:22 PM


Originally Posted by 84stock (Post 8110250)
Read above, solved the ignition issue to find lost compression in my second rotor..:icon_no2:

I don't see that you solved the ignition issue. Looks like you just bailed out with a seal problem.

Do you KNOW that your ignition is OK? Do you think the parts swapping you did has solved the ignition problem.?

swbtm 04-19-08 11:28 PM

This might be pointing out the obvious... but I didn't see you mention it above....

have you checked that your spark plug cables are good? If you reused them on your rebuild then they might have little cracks that would only allow a little amperage through...

yup i know how to read.... you did state that you had 3 nice whooshes as doc previously stated... did you notice manage to get a compression test before you switched out all the ignition components? It might be a good idea to put everything back as it was to get a baseline...

84stock 04-20-08 02:17 AM

Got the ignition working, full 12 volts to the coils and spark. While I could hear nice swooshes, rear rotor only put out 30 psi while the front put out 90 psi. Figure I punted a couple apex seals over-revving it or detonating from the shitty fuel (couldn't even hear the detonation with the open header). http://media.putfile.com/blown-rx7-compilation

bliffle 04-20-08 07:58 AM

But what caused the low coil voltage you reported earlier? Bad connection, short, battery corrosion, discharged battery, etc.?

Next time someone reports a poor running engine with low volts at the coils we'd have something to look at. It happens.

84stock 04-20-08 01:02 PM

Weak battery, once under a boost it picked up.




Originally Posted by bliffle (Post 8112321)
But what caused the low coil voltage you reported earlier? Bad connection, short, battery corrosion, discharged battery, etc.?

Next time someone reports a poor running engine with low volts at the coils we'd have something to look at. It happens.



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