rsrsrs

iTrader: (9)

Wondering what can cause this to go bad. I have literally spent atleast $300 within a year replacing this damn part.

At first I thought it was because I had a system hooked up in the car and a leak where water went over the stereo wires. While I had the system in the IM did go bad more often. I haven't had the system in for a year now and the IM hasn't gone bad for a long time. Yesterday it crapped out as I went to pass someone.

Sooo yea, what causes this to go bad since it seems to be a reoccuring problem for me.

SageMoonblade

Normally water or age will be the main causes for going bad. In your case however it sounds like there is a short in the ignition system someplace.

J91

I had a bad, or just wornout pickup coil in my dist. I went throgh two modules in about 15 months, fixed the pickup coil and never lost another module? Can't say if it was the problem for sure, but worked for my problem...

regal301

there has been a lot of cheap aftermarket modules that dont last,mostly autozone.

other causes.......... bad engine ground ...........bad coil...........

Maverick H1L

iTrader: (8)

Just a few that I have either heard about or experienced:

Heat, bad grounds, water, shorted plug/plug wire/coil. And, of course, the most tricky one of all to get rid of: an AC voltage spike. That's right, an AC voltage spike. This comes from the alternator diode assembly. I've replaced 2 of the damn things in the last 3 months and I can't get rid of it. If you hook a DMM between the BAT terminal and a ground and set the meter for VAC, you might find it. The ignition module doesn't like this any more than the ECM does, just as a warning, which is why I plan on installing diodes in each of the ECM power wires when I get a chance.

regal301

what are you using for modules?

i went through this before, on 3 seperate cars, wifes module went , so i bought 2, one for mine and hers while i was there as preventative maint.,one lasted 2 days the other 2 weeks,got them replaced with 2 new ones ,and one went out again the day after,so finally gave up put in 2 boneyard gm modules i had and now 6 years later,still no problems.the third was a ground issue.i cant tell you how many customers cars ive gotten bad aftermarket parts for.

Maverick H1L

iTrader: (8)

If you say so. My GM module lasted the longest of the 3 I've had to replace... all of 2 years. I ordered a Fiero dizzy from eBay, and I hope that one has a GM module, and a GM pickup as well... Maybe I won't have to replace the module again next year that way.
The Wells unit that was in the car when I bought it ran the engine but couldn't be timed, the GM module flat out died after about a month of crazy misfiring 2 years after installation, and now I have a new problem that I don't know what's up. At least I won't have to pay for another module.

2_point8_boy

The number one reason that ignition modules go bad is because of heat.

On most of the cars that have a recurring problem with this, they have the original distributor in the car. As the distributor ages and wears, the bushing in the shaft goes goes bad and starts to cause excessive heat. The heat travels up the housing to the bottom plate of the distributor and cooks the module.

If you have the original distributor in the car, replace it as a unit and there's a VERY good chance that you won't continue to have to replace them.

mtwlkn122

I know this is a stupid question but what size are those two bolts that hold the module in. I CANT SEEM to find a good match! Ive had a module laying around for awhile and havent installed it cause i cant find the right size socket/wrench to get those off! The fact that im missing a few tools around the garage somewhere also pisses me off but oh well(im one of those ppl that has everything in its special spot, then i have an older dad that leaves stuff all around the house and garage and yard and blah blah blah...errrr hes so agrivating; cant wait to get the apartment finished!)

Maverick H1L

iTrader: (8)

Same size as the hex part of the cap screws and the screws holding the dash pad in, 7/32". Don't know the metric size, but that is what works for me.

2_point8, I'm sure I'm not the only one who doesn't exactly have the $200+ for a new dizzy assembly right now. Also, most people don't know that the 2 round things in the plate are for ventilation (they're grills). I took almost an hour cleaning mine the last time I had the dizzy out they were so gummed up. If you can't see through them, they need to be cleaned with some kind of solvent (I used PB Blaster) and a wire brush.

2_point8_boy

You may not have the money for it, but do you have the money to be replacing ICM's every month for the next year??? The bottom line is that if you want to fix the symptom, you need to fix the problem. Spending $250 on a distributor once and not having to replace an ICM for 5 years is WAY cheaper than the $300 he's already spent on new modules.

There are no moving parts in the ICM, therefore nothing to wear out. The only things that kills electronics are moisture and heat. If there's no moisture in the area, but you continue to have a problem, then there's an issue with heat dissipation/production.

That's actually not 100% true, voltage spikes can also kill the module, but it's very unlikely that multiple modules have the same problem with spike protection.

regal301

5.5mm

Maverick H1L

iTrader: (8)

Point 1: Which is why he should make sure the vents are clear before he goes and spends $200+ on a new distributor. Cost, maybe $10? Proper ventilation will dissipate the moisture and heat better, right? You're also forgetting that not only do overheating and moisture kill electronics, but so does overcurrent and high voltage (not just a spike). Also, going off topic just a bit, how would you explain how I've seen a few cars going down the road, that have those LED tail lights (mostly Caddys), can have a few of the individual LEDs die but not the whole strip (brake light across the tail gate/trunk lid) or the entire tail light? A diode is an electronic device, right?

Point 2: If he continues to replace the module with pre-existing voltage spikes WITHOUT correcting the spikes (not assuming he has them, just saying), doesn't it make sense that the modules will continue to fail because he isn't correcting the REAL problem? They're still going to fail, even if he DOES replace the entire dizzy assembly because it's actually the alternator or whatever that is (possibly) causing the problem and a dead module is just the result.

Either way, I'd still do some PM, since you have to replace it again anyways. Clean the vents and clean all the grounds you can see before you go and spend a lot of money on something that might not work anyways. Don't forget the heat sink grease under the module, and don't forget to clean the old grease off of the dizzy housing. If you have to, go to RadioShack or BestBuy or somewhere and get some of that copper heat sink grease they use in high-performance computers to make sure the module has good heat conduction through the bottom plate. Clean up the mounting screws as well, since they provide the ground for the module. Also check ALL of your connections. Loose connections can cause arcing (especially with the plugs and wires).

I'd replace the entire assembly as a last resort (not looking forward to rebuilding mine but the plastic part of the connector on my 23 year old PU coil refuses to hold the terminals and reassembling the thing is a PITA because they slide out the back, and I lost the bid on eBay), kind of like how a lot of troubleshooting charts end with replacing the most expensive part of all, the ECM.

(and now my argument ends... kind of a cma thing)

regal301

ya ok..........................

the heat soak from the engine 200-240 deg is as hot as it will get. no worn brass bushing would ever get any hotter than that ,and not melt and seize,resulting in shearing the dist. drive gear pin. not burning up modules.you most likely have a poor engine ground or bad coil, the module is a switch,on the hot side ,and a bad ground or low resistance on the load (ign coil) will cause excessive heat and voltage through the module and kill it.

regal301

how old is the coil in your car?if its old or original get a new one.they are prone to failure.

2_point8_boy

The ICM is actually on the ground side of the coil, not the hot side. A bad ground will NEVER cause failure since high resistance in a ground causes lower amp draw, and nothing EVER dies from too little amp draw. A short in the coil could...I'll give you that.

mtwlkn122

Haha thank you guys for the sizes on that. Ill have to go check it out today.


And guys im sry but id have to agree with 2.8 boy, replacing the whole thing will be alot cheaper in the long run. Unfortunately, with the economy the way it is, ppl dont want to shell out any "large" sum of money for anything right now. Im a salesman for the fastenal company and you wouldnt believe the amount of ppl that go crazy when a bag of 100 bolts is xx.xx dollars. Or even more often they say "the nuts arent included with the bolts!". Even if people do have the money they dont want to spend it. BUT if your being money smart, like 2.8 boy said, it would be cheaper to replace the distributor now then keep replacing parts in the long run.

regal301

the module is on the ground side .............

a bad ground will kill a starter,alternator,or any other number of things ,your wrong on that.i melted 2 sets of plow pump motor brushes before running a new chassis ground on my s10.

at least ohm the coil out hot , or replace it before getting a dist.
you can pull out the dist , and see if its worn but i seriously doubt its causing any of your problems.

DNK

This is a good conversation as I had both Heat and Moisture as I had a header tank leak caused by the ICM plate rubbing against it and creating a hole. Instant moisture, the heat came later when the car over heated.
Why I posted is, I am looking for a connector to go to the P/N side of the ICM. Can't seem to locate one.
Any help
Thanks

mattchevy

I have an 1988 chevrolet camaro IROCZ 350TPI I have replaced the spark plugs and plug wires. Along with the coil and the distributer and my ICM keeps burning up any suggestions?

J91

Bad Pickup coil in the distributor will wreak havoc on the module, if the pickup coil is bad the dizzy is probably worn out and could use replaced....

mattchevy

It was a new distributer a year ago its a summitt billet street strip