Car dropped dead.... cause?

[King_V]

Ok, so, I've done a tune up in the past few months - new plugs, wires, cap, rotor, fuel and air filters, PCV valve and screen.

I've also recently replaced the battery.

I have noticed in recent weeks an odd stumbling that happens sometimes at light throttle, very light throttle, then goes away. At first I thought it was when the car was cold, but it seems that it almost always happens about 2 minutes after first starting the car, then goes away shortly thereafter, regardless of temperature outside. Even if the car's not fully cooled off, and I start and drive it again, it happens.

Today, I was at my son's birthday party at his mother's house. She lives about 20 miles from me. Was there for about 3 hours, then went to leave.

I started the car, it idled perfectly for 10 seconds or so, then cut out.

It would not restart. It'll crank eagerly, but just won't catch.

I checked at the schrader valve at the fuel line underhood, and the resulting spray of fuel on my hand indicates plenty of pressure.

I am guessing it has to be the coil or the ignition module. Both, as far as I know, are the factory original parts, with 26 years and 111,000 miles on them. I figure I can confirm a no-spark situation if I attach my timing light and get nothing while cranking, right?

Am I going down the right track? Or is something else likely the culprit?

If it is the coil or rotor, which parts stores' brands would be better to go with, or which to avoid? Napa, Autozone, Advance, and Pep Boys are all close to me.

Thanks in advance - gotta get this thing up and running to get to work Monday!

[L1011tristar17]

Have you checked the TFI module? Mine would do the exact same thing and that turned out to be the problem.

[King_V]

TFI Module? That's the term for the ignition module, right? The flat gray thing approximately the size of a Hershey bar that's on the side of the distributor? Or are the TFI and ignition modules two separate things?

How do I check them to narrow down if it's that item or not?

[VicCrownVic]

+1 TFI/Ignition Control Module, it is the flat gray module on the side of the distributor that you are describing, from your symptoms it is the most likely culprit. The one on my 89 died last summer, I'll have to do some digging but I thought I had come across a way to test it a while back. I'll post if I can find it again.

[VicCrownVic]

Not finding what I was looking for, I'm pretty sure I have it bookmarked on my computer at home, but I'm at my parents' house for the weekend.

[sly]

also pop the cap off the dizzy and check to make sure the position pickup is still in one piece. When those get old, they tend to lean into the fins and get chopped up.

[King_V]

Well, found this page and it seemed like a lot of the resistance measurements for the TFI were close - though some were off by about 15% or so. It doesn't say HOW close the resistance measurements have to be!

Stuck it back in and did the probe of the blue (#1) wire - stabbing my finger in the process, dammit! . . . and I have 5 volts when cranking.

Wish me luck, going to stick in a new module and see if that does it.

EDIT: Module it was! Stabbed myself for nothing checking PIP . . but the one site did list that as being a more common reason for no spark than the TFI (with TFI coming in a close second) . . but, hey, learning experience. I would just prefer my learning experiences in milder weather.

[King_V]

Oh, and I did check the position pickup as well - looked just fine and still in one piece.