Possible problem with ignition module

[andrew21]

So I inherited this cute little '89 Ford Festiva that had been sitting for two years. The word on it was that the ignition module (mounted inside the distributor on this model) was bad. We checked everything else out and agreed that this was probably the problem. As the module somehow costs way more than a remanufactured distributor with the module in it, I bought a reman distributor and put it in.
The car started up and ran great for about 5 min, then suddenly quit. I checked the battery connection and got it to turn over again, but not start. We checked and found that there was no spark at the sparkplugs. We then checked the coil and all the wires - all of them checked out. We have power at the distributor.
So all we could come up with is that the module is somehow bad already, possibly defective? though it's strange that it started up at first and then went out.
I'm wondering if anyone has any insight as to some other problem that could be causing the module to go bad? or maybe we're wrong about it being bad?
The auto parts store was accomodating enough to order me another distributor and exchange it, but I want to get some other opinions before putting it in, in case some other problem might zap the module right away, since it was bad when i got the car, and the new one i put in seemed to go out right away.
Any ideas?

[WmWatt]

There is some information on a webpage here

http://www.ag384bn.bravehost.com/Cars.htm

Good luck.

[25Horseplay]

Make sure all your grounds are tight. When the module went out in my 89 the tach started acting all crazy right before it went out and I had to push the car home!! LOL

[jglutz]

I'm wondering if anyone has any insight as to some other problem that could be causing the module to go bad? or maybe we're wrong about it being bad?
.................................................. .................................................. ........Any ideas?

Good question and concern...however....sometimes the failure is the part itself....not pre nor post. The circuit internal to the dist module is pretty simple the input is 12 volts and the output is the TDC/Tach signal. The most common failure is breakdown of the insulation/potting or crud build up internal to the dist that inhibits the pulse pick up. Some here have disassembled the dist...cleaned them up and reassembled them with improvement.

[deathegg]

I installed a new module in my dist a few months ago, it only took about 10 minutes, and now it starts up like it's a new car. Got it pretty cheap on Ebay. I got lots of help here at FF.com (you know who you are!), otherwise I wouldn't have known where to look for the problem. While it was out I cleaned the inside of the dist, and also was sure to use the dielectric grease for the module.

[andrew21]

ignition control module again!????

wow...after buying a remanufactured distributor, then exchanging it for another, as it went out immediately, I finally got this festy running. It's been running strong for a couple weeks, figuring out an oil problem and other stuff, and then suddenly the other day it cut out completely while driving along in 2nd gear. It started up again, but then last night I started it and it died, then today again, it would mostly just turn over but not start. We checked for spark and it was intermittent. Usually no spark, then sometimes we got spark. We checked the coil and it's ohm readings are right in the appropriate range. could it possibly be ANOTHER faulty ICM, or is there something going on here that I don't understand? I found some mention of the pickup coil on some people's similar problems. any input?

[sanjeet]

I may be wide off the mark but a problem that can occur and its a pretty obscure one is an open circuit on the ballast resistor, what the ballast resister does is lower the voltage to the coil when the engine is running normally, so what happens is you crank the engine it starts and you release the key and it stops.... because the ballast resistor is open circuit

[FB71]

Festiva doesn't have a ballast resistor.

It sounds like you have a bad coil. Here's the scenario; the coil is functioning, but has reduced primary resistance. Insufficient primary resistance will cause excessive current flow, which is provided by the module in the distributor. Excessive current flow will overheat the module, eventually causing it to fail.

If I remember correctly, primary coil resistance should be 3-6 ohms. This can be checked with a DVOM (Digital Volt/Ohm Meter) at the two screw terminals on the coil. Make sure the wires are disconnected from the screw terminals before you check the resistance. Otherwise, you could get a false reading thru the vehicle wiring.

If the coil is less than 3 ohms, that's your culprit. Replace it and the distributor, and you should be good.

Again, this is provided you have verified all of your grounds are in good condition first.

[sanjeet]

FB71 your right the Festy does not show a ballast resistor and I agree shorted turns in the primary winding of the coil, FB71 the distributors can get a bit expensive and that's also for second hand units and in NZ they can cost around $120 with a guarantee. there are so many issues with distributors that can cause problems and most probably best to just replace it.