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For those of you FI'd guys who had your module go out....

K5MONSTERCHEV

K5MONSTERCHEV

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Im talking about the ignition module, in the distributor. For those of you who had it take a dump, or needed to replace it, I am curious, what kind of symptoms did you have?

My TPI has around 700 miles on it. I put in all new parts. Recently I have been having problems with it. At first it would fire up then run for a few minutes and shut off all of a sudde, not fuel, ignition problem. However, it wouldnt start back up, until you let it sit for a while. Then shortly after it got worse, it would take a while to start and only run for a few seconds, then wouldnt start back up for a while. This literally happenned overnight. My firend drove it around while I was working on her blazer, I parked it for a few months, went to drive it and had ths problem, so I parked it again, and recently got a chance to work on it. I just cant belive the module went out already, after only a few hundered miles, whats the deal?
 
yeh, i had weird stuff with mine, would run bad & randomly shut off and not want to refire, then let it sit for 10 mins and itd be fine(not cool at redlights). I had one die, just out of the blue, put in another one, a week later it was dead, another one, it was dead in like 2 days, another one, and im still runnin it(like a yr later). I just got a couple crap ones, i dont really know.
 
I have had a module quit a few times over the years and like 85mudblazin said it just quit with no warning.. A module can work fine one minute then you turn the truck off and try to start it and it will die that fast..

Make sure you get the GM module even though it cost more then the aftermarket version.. I made that mistake and the truck won't start as fast because it dosen't produce the same amount of spark.. IIRC the GM module is about $50 bucks and the aftermarket one is about $20 bucks..
 
if you are unsure wether its the module or not you can have it tested at most auto parts stores.

Yea I was sitting at a red light first in line when mine went out. was fine except it was rush hour on a major road :mad:
 
it went out on me while i was driving i got fuel and air but no spark so i checked everything and i bought the msd box that takes out all that stuff and she fired right back up.
 
Have you checked trouble codes? If there are none except the usual 12. Its most likely the ign module. Your symptoms sound like a bad module.
As said in above posts get a GM module. Sometimes the cheaper and even aftermarket like MSD modules dont last long. Sometimes all it takes is a hot summer day to make one fail.
Many auto parts stores will test them for you if you pull it and take it to them.
 
mine quit on me managed to get it running again then two days later hauling a load of dirt and it went out had to replace no problems since
 
I had two go out on me in my p/u.. One just up and quit all of a sudden... No warnings. :( The other gave me some spitting and spuddering before it poop'd out....
 
Working on a no-start condition of my own.

Had done this to me before just twice, only once bad enough for me to leave the truck in a parking lot.

After the truck sat for a few months (changing tranny, t-case, broken rear axle) I fired it up, and let it get to operating temp. Shut it down, no start. Went through the troubleshooting chart for no-start, and although there is some weirdness with one of the tests, (my scanner has never registered cranking RPM, nor can I force it to via the GM test) it appears to be a module issue. Never dies while driving, just waits until I shut it off.

Just because I had a spare around, and I wanted to see how tough it was, I decided to swap the module. The one I put in was used as well, not even sure where it came from. Now the problem is 100% when the vehicle is hot.

The only thing left that I'm going to do is test each wire in the ignition circuitry to make sure I don't have a bad wire somewhere. I doubt it's an issue in this case, but my MAF error was because of a wiring issue. Never hurts to check stuff like this.

One test given to me over on thirdgen was to run a test light between the white coil wire and 12V. The light should blink when the engine is cranked. If it doesn't, supposedly bad module. Mine fails that test as well.

I've never seen official reference to this, but after being told this, I saw it with my own eyes. GM modules have fail indicators built into them. There is a yellow dot in the very center top of my modules. When the modules fail, supposedly this dot turns into an upward bulge. The module I pulled does have this, the one I installed wasn't bulged, at least when I installed it.

Since all my stuff is high mileage used, and if it hasn't failed yet, will in the time I own the truck, I'm putting together an ignition parts list of AC Delco stuff that I'm going to order from GMpartsdirect.com. Coil, pickup, modules.

GM number for '88 and '91 (two years I crossreferenced) TPI Camaro module is 10482827, AC Delco # is D1943A. Almost $40 at GMPD, ouch. Distributor is 1103952: $161. Not sure how complete that is.

pickup/coil testing Since you'll be inside the dist. anyways. :)
 
yellow spot?

I know GM "matches" the module to the pickup coil and ignition coil by putting a spot of yellow or white paint on the module,coil,and the dust cover of the distributor....the "yellow" one goes with the coil with red and yellow wires,and the "white" one goes with a coil with a white wire..I guess the pickup coils are wound in the opposite direction on distributors that rotate counterclockwise VS clockwise,and the module and ignition coil must match(though I've used ANY coil in an emergency,and the truck still ran ok!..???)...never heard of the "bulge" being an idicator of module failure,but I guess its possible..

I've seen EFI modules act goofy too..one friends 94 GMC with a 4.3 would not fire up some mornings--until he used starting fluid!--then it would start and run normally the rest of the day--sometimes it would not do it again for days or weeks-then it would act up every day!..he tried another "used" module,but it started doing the same thing a few days later,leading him to believe it was not the module...

Several garages and a dealership could not find anything wrong,so in desparation he had a genuine GM module installed at the dealer(at a cost of 150 bucks! :eek1: )and its started every time since!...that was 6 months ago!...I guess the EFI module controls both the ignition AND the fuel injectors,and sometimes one "half" of it wont fire the injectors properly,but it will still have spark,or vice versa.. :crazy:
 
Usually ICMs will sputter at high rpm and eventually fail. Sometimes they just plain go. For $20 you can get a new one. Or you can get a high output one from GMPP for about $40. A normal one draws 2.5-3a and a high output one draws around 4a.

If it's heat related it's usually the pickup coil or the ignition coil. If it is to the point where as soon as the motor gets the underhood hot then it's usually a coil wire problem.

I always keep a spare coil, rotor, and ICM around. If something goes bad I use T&E to fix it.

Don't forget to put thermal grease on the ICM. If you don't, it'll quickly burn out.
 
The only time I've seen a problem like you're describing as when the engine is hot, the problem was a bad coil. The car would run fine until it warmed up, then it would die. The coil would only give a spark when it was cool.
 
Bad coils won't result in spark at the plugs....well, of course part of the test procedure is to use a spark checker to make sure it's putting out enough voltage, so saying spark=run isn't necessarily correct.

If your injectors aren't firing when the engine is cranking, it's also not a coil problem.

From looking at the diagrams of the module, if my particular problem is the module, more than likely one of the internal switches is getting stuck once it warms up. That is fine when the engine is running, but once shut down, the swtich doesn't go back to normally closed or open like it should.

I second code checking. On MAF setups, MAF problems can result in stalling or problems starting. Not sure how a MAP system would handle MAP sensor problems.
 
Wow, thanks for all the input guys! I have no codes related to the ignition module (no code 42). Yes, the next module I buy will be a high quality one, I am sick and tired of buying crap parts from places like Kragen and they dont last worth a ****. Dyeager, thanks for the info and PN's, never knew about the bulging thing.

I had wondered if mine was the coil, (at first thats what I thought it was) but the fact that it does it when its cold, not a heat problem. I didnt do as much diagnosing that I should have on it, but I had some problem last year with the module when I first did the TPI, with like 20 miles on it. I will still check to see if I have current at the coil (white wire).

Dont think ill have it ready for Blazerfest.

Thanks again guys!
 
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