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-   -   84 GSL SE Igniter - How to Test (https://www.rx7club.com/1st-generation-specific-1979-1985-18/84-gsl-se-igniter-how-test-1087904/)

RXrick 08-09-15 08:05 PM

84 GSL SE Ignitor - How to Test
 
How can you tell if one or both of your ignitors are bad?

Besides looking at the dashboard tach, how can you test?

Do both need to be good for the car to start?

Thanks for reading.

j9fd3s 08-09-15 08:35 PM

best way to test is with a timing light, or the tach. there is a test procedure in the FSM, but its easier than running the car, so a marginal ignitor will pass.

if the car runs or not depends on the model, the 84-85's have the fuel pump and or fuel injection tied into the trailing ignitor, so they won't run at all with the trailing bad, and they run badly with the leading bad.

KansasCityREPU 08-09-15 09:12 PM

Here are a couple of threads on how to build an ignitor tester.

https://www.rx7club.com/1st-generati...esting-577683/

https://www.rx7club.com/1st-generati...tester-495974/

RXrick 08-09-15 10:49 PM

1 Attachment(s)

Originally Posted by j9fd3s (Post 11952709)
best way to test is with a timing light, or the tach. there is a test procedure in the FSM, but its easier than running the car, so a marginal ignitor will pass.

if the car runs or not depends on the model, the 84-85's have the fuel pump and or fuel injection tied into the trailing ignitor, so they won't run at all with the trailing bad, and they run badly with the leading bad.

Does this recording help solve the problem?

RXrick 08-09-15 11:51 PM


Originally Posted by j9fd3s (Post 11952709)
best way to test is with a timing light, or the tach. there is a test procedure in the FSM, but its easier than running the car, so a marginal ignitor will pass.

if the car runs or not depends on the model, the 84-85's have the fuel pump and or fuel injection tied into the trailing ignitor, so they won't run at all with the trailing bad, and they run badly with the leading bad.

Can you please post the (PDF) page in the FSM here for us to see and learn?

Thx

j9fd3s 08-10-15 12:08 AM


Originally Posted by RXrick (Post 11952753)
Does this recording help solve the problem?

nope, what is the problem? the tach is moving while its cranking so the trailing is working...

j9fd3s 08-10-15 12:09 AM


Originally Posted by RXrick (Post 11952768)
Can you please post the (PDF) page in the FSM here for us to see and learn?

Thx

Foxed.ca - Mazda RX-7 Manuals

RXrick 08-10-15 12:17 AM


Originally Posted by j9fd3s (Post 11952777)
nope, what is the problem? the tach is moving while its cranking so the trailing is working...

Yesterday the tach spiked up to about 1000 rpm about every second, Now it just stays as zero. That is what I meant.

Someone on another thread of mine said if you can see the tach spike the ignitor is good. I don't see that happening anymore.

KansasCityREPU 08-10-15 10:31 AM

It's very hard to diagnosis problems over the internet with 100% confidence. At some point, you need to take the suggestions that are given and test things yourself or hire someone to do it for you.

We can all give our suggestions based on our experience, but none of it means a lot until either a part is replaced or tested. it's time to start testing. This will be a good learning experience also.

LongDuck 08-10-15 10:52 AM

Agree with the KCRepu-man, as there's nothing better than getting your hands onto the problem parts and start testing them.

Unsure what the OP means by 'tach spike', as my 84-SE tach on startup just shows whatever the cranking RPM is for the engine and tends to bounce a bit as the rotors find compression and the RPM bumps along. When it starts, the tach shows actual RPM - so don't know what you mean by 'spike'.

The tach on our cars is driven by the white wire coming off of the bottom spade of the front (Trailing) Coil, so if you're NOT getting a Tach signal, you're not getting trigger of the coil which could be a bad coil or a bad igniter (or a bad coil wire, or a bad ground, or a bad power lead, or...). You won't know until you get in there.


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