nighthawk34

I have a question.. I have a 85 GSL-SE 13B FI rx7..I replaced one of my coils because i didnt think it was working... No.. Is there a way to test a coil.. I can unhook it and put it near some metal on the car and it sparks very well.. however.. if i unhook the front coil.. the engin runs fine.. if I unhoock the rear coil the car will not run..
I can switch the 2 wires and as long as the rear coil wire is hooked to either coils it runs.. however it will not run with the front coil by itself..

Have a confused ya all yet|?

Let me know what I need to try..

By the way the car misses like hell.. and than sometime.. it run like a well tuned sewing machine.. than dies and runs like hell again!

Siraniko

iTrader: (13)

Ground the primary spark plug wire

rolfs_7

does the tach kick in the 85 se when tryin 2 start?? i have noticed my car is hard 2 start somtimes and somtimes not and my tach doesnt always bounce but somtimes does? odd thx

Siraniko

iTrader: (13)

here's a hint. If you start the car without the pig tail in the alternator, what would you see. thats where I would start for bouncy tach on initial start.

jarath

Is that little blue connector always connected to the front coil itself? The trailing coil blue connector needs to be connected or the SE fuel injection system won't kick in as it is computer controlled. I found this out the hard way when I accidently had the coil wires reversed. Blue connector goes to coil closest to front of car which is trailing. All we did was have the trailing and leading spark wires reversed and it was totally dead till we fixed it because we THINK the computer was cutting the fuel injectors... wiring diagram supports this theory if I read it correctly

FWIW, reason I ask you to check this is the car shouldn't run with the front coil removed as it appears it is since the FI shouldn't be on.

Dom

The front-most coil runs the trailing plugs and the rear-most coil runs the leading.

Without the trailing plugs running the tach and fuel pump will not run. The work around for this can be found here:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/lost-both-ignitors-once-550045/

You may also want to make sure that the ignitors are working. Are you getting spark off either of the leading and either of the trailing plugs?

If either of the ignitors are dead and you can't get a junkyard replacement go with a GM equivalent. Instructions are here:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/how-gm-igniters-replace-j-109-a-527209/

jarath

From my observations in the service manual, the fuel pump doesn't have any connection to the coils at all. The tach does though. The only thing directly connected to the coils is ECU plug positions U (directly to trailing coil and Tach), F (injector 2), H (injector 1), and the igniters. I am guessing from this that if the coils aren't hooked up right, even if you hard wire the fuel pump it still won't run because the injectors are missing their ground.

Dom

Woops, missed out on answering your question on testing the coil.

For that you'll need a meter set to ohms. Place the test leads as shown.

The reading should be around 1.35 ohms for either coils.

Dom

That's right, no hard connections from the coils to the fuel pump. But the fuel pump is connected to the computer and the trailing coil does send a signal to the same computer.

rolfs_7

1.5 on leading and 2.3 on trailing.....should i be looking at getting some msd blasters???

jarath

Ah gotcha, ok that thread makes more sense now.

Dom

FSM says 1.35 +/- 10%, so the 2.3 is too high and the 1.5 is at the upper limit.

Are you getting spark off either the leading or off either of the trailing plugs?

But then again, this is not your thread...

rolfs_7

sry for the jack but im not sure if im gettin spark or not i think it works somtimes and somtimes it doesnt...screw it ill get get msd blasters off ebay. thx

Dom

So you don't know if you're getting spark and you don't know how to verify, but you're going to go with an MSD...

You may be getting in over your head.

rolfs_7

last i knew i was gettin spark i think it comes and goes cuz i can feel it not run right and pick up i dunno im just gonna replace the coils i had plans to a long time ago.