TurboSmoke

how do i test a coil to make sure they are working right. cause after 2-3 revs my tac falls to 0 and someone said it was my coil

HAILERS

Theres a way that will leave no doubt in your mind if the coil is good or bad. Professional mechanics please close your eyes and go to another post. You may not like what you see.

I'll assume its your LEAD coil assy that you are worried about, the trail isn't worth looking at. On the coil assy, pull each of the two plug wires out of their bores, and lay the ends just at the top of the holes. Remove your cas. Turn the key on. Turn your cas in a counter clockwise direction. You should see bodacious sparks and the crackle of the coil firing.

Now there is a more high tech method than the above, and if you care not to try it, just say so and I'll copy the procedure out of the haynes manual.

Actually I think a lot of people do the above method. I've seen it recommended on this site before, I just never tried it till a day or so ago.

TurboSmoke

remove my cas what cas

HAILERS

Never mind. Someone will come along a little later with a method.

Oh, there is something you can use. Its online at http://www.fc3s.org if you look around on that site, there is a free download of the factory service manual. Its free and worth looking into. There is another site with a factory service manual, its at http://www.iluvmyrx7.com and its a free download also. Or there is something called a HAYNES manual that cost money at say PepBoys or Autozone. Each has a section on checking the coil assys. The HAYNES might be your best bet.

TurboSmoke

what is cas tell me

HAILERS

CAS is the crank angle sensor. Looks somewhat like a distributor. Its got a black plate on top held with two screws. Its what determines when the coils fire and the injectors inject. has a little white plug on it. I sota dropped that suggestion since you would have to pull it out, and then reinstall it. Now pulling it out is easy but putting it back in is a little more detailed and a timing light is required to set the timing after you do that.

Not knocking you, but I got a hint that maybe you might not have a timing light or maybe have not set the timing on this car before.

HAILERS

Following are two jps out of a haynes book on checking the coils, lead and trail.

HAILERS

And the second page

TurboSmoke

thanks for the help i will do it in the am

HAILERS

And the values:

banzaitoyota

A good reason to keep a spare CAS on the shelf. Thanks Hailers

TurboSmoke

if my coil is bad how much do they run for a s5 na

inboost

Doesn't the tacho signal come from the trailing coil pack? I would test the ignition on all of the coils to be sure.

TurboSmoke

yes they run off the trailing coil pack

HAILERS

Damn me to the hot place Banzitoyota. I pulled the one on my car when I had a couple of spares laying around. Waddaa dummmy I am.

Turbosmoke.....I'd just forget about the jpgs, pictures that I posted. Go ahead and pull the cas out. It has one 10mm size bolt at its base that hold it in place. Take that out and lift it out of the housing.

Then do as I described earlier. In fact this time take the sparkplug wires out of the coils and just lay them in the openings of the coils where they are just inside the hole.

Now take the black cover off the cas. Its held with two screws.

Turn the key to *on* not *start*.

Turn the cas by rotating the gear on the bottom. Looking into the cas's top, make it rotate counterclockwise.

I guarantee the coils will be spitting sparks and crackling snap, crackle and pop.

OOOps. Got to go
do some work now.

vmb

i had this problem , i ran a big *** wire from the body of the tranny to the firewall and problem was solved

Felix Wankel

Line the leading timing mark up before you pull the CAS out, that way you will put it back in the right way (with the dimple and notch lined up).

HAILERS

You know, VMB is right. I never got past your first sentence where you wanted to check the coils out. Trail coil makes the tach work. Might check the connections at the trail coil assy(rear set of coils) and that the trail coil assy is bolted down good to the chassis. If a coil assy body does not have a good bond with the chassis, it will not work and if its a poor, somethimes bond, will make your tach act up and the trails not to fire.

Not nearly as much fun as watching the sparks as you twirl the cas gear. Yeah, check your grounds at the coil assy and connections first. Sorry 'bout that.

blu_gxl

dude, just do what the manual says don't mess with the cas. just get an ohn meter and place the sucker across the two bolts that are under the platicthat tells you t2 or t1 then it will give you a reading you have to disconect the battery ground first (sorry forgot to mention) then the reading at the coil will be within .2-1 ohms if it's more replace. i just don't suggest taking out your caS because if you get it in incorrectly you will not be happy with the results.

HAILERS

Sorry BLU-GXL......I'm just argumentative today. If he spins the cas he'll also check the operation of the igniter at the same time. And learn how to install the cas properly.

Kinda weak argument, eh? Yeah, your right. Still.......