carey83gsl

so i was driving on the freeway the other day, and my tach died. after doing some reading and searching, i discovered that that could be a sign that the trailing coil is dead / dying.

so, i disconnected the spark plug cable from the trailing coil and held it near a ground on the engine block and sure enough, no spark (but spark came from the cable from the leading coil when I did the same thing).

i went to check the resistance across the coils (as per chilton guide), but couldn't get that to work - both wouldn't register on the ohm-meter. also, the tach began to register when i hooked it up to the leading coil, but the car then wouldn't start (???). but the tach would respond during cranking, which it won't do when its hooked onto the trailing coil.

and if only the leading coil is hooked to the distributor, either trailing or leading, the car will start and run. but the car will NOT start or run if only the trailing coil is hooked onto the distributor.

also, the voltmeter has a mind of its own. sometimes it reads between 13 and 14, others it's just below 12.

So, is the coil the only thing that could be bad? or could the ignitor be bad / how would I check that? Is there wiring going to the coil that I should check? Would a bad coil cause the voltmeter to go crazy, or could there just be a bad ground somewhere?

I'm pretty lost. any help would be appreciated.

bliffle

Could be igniter. there's a battery-and-bulb test in the FSM, but I've been fooled by it.

bliffle

Swap the two ignitors and see if the symptoms change.

Get at least one spare ignitor, either from a local junkyard or Pick n Pull or from eBay or from the classifieds here at the forum. Should be about $20.

carey83gsl

alright, thanks. i'm gonna pick up a coil from someone later this week who should also have ignitors. i'll let you know how it works out!

edit: the ignitors are on either side of the distributor, right? little black boxes? which is trailing, which is leading? and can i just swap the plugs, or do i need to physically swap the ignitors?

thanks!

j9fd3s

iTrader: (3)

90% chance its the ignitor and not the coil. swap ignitor connectors, see if the failure follows, replace ignitor.

the FSM test kind doesnt work, because you're not cycling the ignitor fast enough, and at temprature

carey83gsl

alright. i should be getting the car back from the shop tomorrow and i'll check out the ignitors then. if i swap the connectors, then the coil that's working should swap, right?

thanks for all your guys' help!

bliffle

Huh?

How do you intend to 'check out' the igniters?

How do you propose to 'swap the connectors'?

You can swap the igniters, and if the symptoms change then you have an igniter problem.

Be sure to use Heat Sink Compound between the igniter and the distributor.

carey83gsl

well, there's plus going into the top of each ignitor, so i was thinking i could just swap those. but i'll just physically swap ignitors and see what happens.

bliffle

Trial-and-error changes that are not informed by a clear experimental goal often result in new problems that can be more severe. But swapping ignitors (really) is OK because they are identical. Swapping leads is dangerous if you don't figure things out in advance.

gsl-se addict

iTrader: (3)

You can swap the connectors...but make sure that the plug wires are disconnected from the engine. Crank with a spare plug in L1 wire (plug body grounded to chassis). Repeat with T1. If before you swapped, T1 wasn't firing and now it does but L1 isn't, then you are looking at a bad ignitor. Remember to swap connectors back. Reversing them will cause T1 to fire before L1.

It is safer and probably has less chance of confusion if you just swap the ignitors.

carey83gsl

update! okay, it ended up being the ignitor. got a pair of new ones (a spare!) for $10, but after putting the new one in, now both coils are putting out a spark, and my tach works (yay!).

new problem: the car now starts up fine (and actually, easier) but now runs rough, won't idle on its own, and won't rev easily. I'll be checking the timing tomorrow, is there anything else it could be?



....oh. just occurred to me i may have unplugged a vacuum line... anywho, i'll update again on this tomorrow.

bliffle

Did you put Heat Sink Compound on that igniter?

carey83gsl

thank you for checking. i forgot. guess it's a good thing that it won't run right now.

turns out i did forget to plug in the vacuum lines to the distributor, so i did this morning, and it will start and run for about 5 seconds tops and then die.

i'll put heat sink compound on the ignitors in the meantime, but is there something else i've missed? are there more than 2 vacuum hookups on the distributor?

bliffle

That's EXACTLY what my SE did a few weeks ago when the trailing igniter failed. Finally, it quit starting at all.

carey83gsl

damnit...which ignitor is the trailing and which is leading? my coils still put out spark though...but maybe i'll swap in another ignitor when i have the distributor out to put on heat sink compound.

bliffle

The trailing ignitor is at the top, next to the alternator.

You don't have to pull the distributor to apply Heat Sink Compound, just put it on the metal side of the ignitor when you install it.

Pulling the distributor may lead to a whole slew of problems if you don't have experience re-setting the timing. Unless you have good reason to believe the PO pulled it and upset timing. But you should be able to determine that with a timing light.

DivinDriver

iTrader: (15)

What was the rationale behind the fuel pump being driven by the ignition circuit, anyway? Anyone know?

gsl-se addict

iTrader: (3)

As bliffle says, trailing is next to the alt. However, since you have confirmed spark on trailing, it may not be the problem. There are a couple of other possibilities:

1. there should be a blue spade connector on the trailing coil (-) terminal. Make sure it is connected. This carries signal from the coil to the ECU. Since it starts, it is probably connected, but double check.

2. on the SEs, the fuel pump runs with the car cranking (key turned to 'START') or running (the door in the AFM open). Take off your air filter and push the AFM door. It should spring back and close completely. If it is sticking shut, this would cause the engine to die after starting. Also related to this is the AFM itself could be bad. Near the AFM, there is a connector with a black boot over it. If you connect a wire between the two terminals in that boot, the fuel pump will run whenever the key is in the 'ON' position (bypasses the switch in the AFM).

3. could be bad trailing ignitor. bliffle had this problem where the trailing seemed to be okay when cranking or using the FSM, but would cut out after the car started. I haven't seen this happen much, but it is a possibility

4. do you have gas in the tank?

5. could throw a fuel pressure tester on there and see what is going on when it dies.

As far as the fuel pump being driven by ignition, it is a safety thing. This way, if you were in a crash and the engine stopped running, the fuel pump would also stop. If it didn't it could potentially keep pumping fuel into a fire or start a fire.

carey83gsl

ah. well, i just pulled the distributor last night to put the ignitor on since it's nigh impossible to remove the screws holding on the ignitor without pulling it out. but i put it back in exactly the same way i took it out (as per chiltons), and i didn't think it would have upset the timing...

carey83gsl

update:

situation resolved!

i got two ignitors for cheap, and not knowing which was leading or trailing, just put them both on. that fixed my trailing spark, but apparently broke something else (?), so I just took the leading ignitor that i had before and KNEW worked, and put that back on there WITH the new trailing one.

so, now i have spark from both coils! hoorah. i think i'm still going to take my alternator in to be tested, the voltage jumps around sometimes for no reason. but at least it runs now