We all know that the Fiero ICM fails once in awhile. Mine on my 85 SE, with 100K miles went out last summer. Is this due to age, or many cycles of heat/cool? So, a new part, that has been sitting on a shelf for 25 years, wouldn't be affected? My main question is, for those of you who have replaced the complete distributor, have you had your ICM fail? What improvements do the (newer) replacement distributors have? Thanks for all responses.
New distributors are all "offshore" units but what isn't. They ICM that is included is generally equivalent to a second line lower quality unit. I recommend that if and when you replace the distributor you at least replace the ICM with a top line unit like a STANDARD Motor products RED BOX. Keep the removed ICM as a spare. When I did mine, I also replaced the cap and rotor with the SMP red box unit. You also might want to explore a heat sink for the distributor....just use the search feature.
Originally posted by sledcaddie: We all know that the Fiero ICM fails once in awhile. Mine on my 85 SE, with 100K miles went out last summer. Is this due to age, or many cycles of heat/cool?
All of the above, it lasted 36 years and 100k miles, can't ask for more than that. When I replaced the module in all 3 of my GT's they were all original and still working, I replaced them as preventative maintenance and kept the originals in the trunk as an emergency spare.
quote
Originally posted by sledcaddie: My main question is, for those of you who have replaced the complete distributor....... What improvements do the (newer) replacement distributors have?
None, actually worse.
quote
Originally posted by sledcaddie: So, a new part, that has been sitting on a shelf for 25 years, wouldn't be affected?
You will get different opinions, but I replaced hundreds of these on GM cars from this era, and IMO the best option is to buy a NOS module and quality pickup coil, replace them both at the same time, use a nice even thin coating of white thermal paste on bottom of module, and install onto a clean distributor surface with clean vent holes. This is the best prevention and should last another 36 years as long as your engine temps are normal and you have good ignition components (cap, rotor, wires, plugs, coil). The problem with modern aftermarket modules (even AC Delco) is they can't handle the heat. There is nothing wrong with using a module that has been sitting on a shelf since 1992.
Here are some part numbers for you to search for...
10482827 - GM alternate catalog 10496269 - 22P manual Both point to D1943A as V6 replacement
D1960A is listed for the 86GT D1943A is listed for the 85-87-88GT Both work on V6
I've also seen all 3 of these scenarios: #10496269 is on the box for D1960A #10496269 is on the box for D1943A #10496269 is on the box for D1992
I'd gladly use a genuine ignition module that was 25 years old and still new in the box. Probably a better item than the new ones.
Keep in mind though, the same D1943A is used in dozens of other vehicles, not just regular cars but lots of Chevy trucks. Probably all the 2.8 and 4.3 trucks. My old S-10 pickup probably used the same part number as my Fiero. Any new module you buy at the parts store is likely to be pretty fresh and new.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Do you think it is possible that the 'heat sink' paste evaporates or dries out over time, so the heat doesn't dissipate as well, causing the ICM to get hot and fail?
Do you think it is possible that the 'heat sink' paste evaporates or dries out over time, so the heat doesn't dissipate as well, causing the ICM to get hot and fail?
I've wondered that myself... although the thermal paste I used Here (along with mounting a heat sink) was applied 14 years ago, and still seems to be doing its job.
Do you think it is possible that the 'heat sink' paste evaporates or dries out over time, so the heat doesn't dissipate as well, causing the ICM to get hot and fail?
I would think that if a heat sink paste is used that has high solids, even if the viscous carrier dried or evaporated, the solids would still transmit the heat away from the ICM.
As for the pickup coil, I've replaced three in different cars. One of them due to a failure. The other two were precautionary due to the degradation of the plastic on the harness end, and the sheathing that covers the coil itself.
Most Heatsink Grease does dry out but still works after doing that. The "oil" is just carrier to move the compound to install. "Oil" can be silicone oil or whatever liquid to make the stuff.
Don't go by fools in PC world saying you need re-grease or buy expensive crap. Worse some PC products are electrical conductive and "liquid metal" that hate aluminum.
That said... I don't use HS grease anymore. Use green label Permatex Brake Grease. Will allow metal to metal hitting and fills tiny gaps to transfer heat. Plus unlike HS grease never dries or runs when hot.
Started this decades ago because Duke DIS ICM need something just to prevent "rusting" between ICM and mounting tray. GM DIS ICM are too big and HS grease won't flow and cause stress to the ICM. GM installs them dry but Dukes have low location and can get crap off of road stirred up by tires.
I use Brake Grease on PC CPU and more because is plastic safe if gets on PC parts. But it is True Grease so some Heatsinks can move after install.
[This message has been edited by theogre (edited 01-25-2022).]
Most Heatsink Grease does dry out but still works after doing that. The "oil" is just carrier to move the compound to install. "Oil" can be silicone oil or whatever liquid to make the stuff.
That said... I don't use HS grease anymore. Use green label Permatex Brake Grease. Will allow metal to metal hitting and fills tiny gaps to transfer heat. Plus unlike HS grease never dries or runs when hot.
So, Ogre, does Permatex make a HS paste? If so, what is the difference with its green label brake grease?
PBG Green label has been around for Decades. More recent also have a ceramic brake grease w/ a lt blue label. Claims even bigger temp range to operate but never tried it.
Isn't a HS Grease/compound and Permatex doesn't make a HSG but most should have it doing brake work. Will flow much thinner because is not a HSG allowing metal touching and fill small gaps too.
HSG is to fill small gaps and mostly stay put years or decades later. Most normal and syn grease will work but still runs cold, hot or both and makes a mess and not plastic safe too. IOW Many things will work same or Better then "standard" White HSG (Silicone oil w/ Zinc Oxide) including Hyped High $ HSG used by PC people to remove heat... White HSG was made 70+ years because most normal grease had same or worse problems and still made because very cheap and does a good job. PBG is plastic safe and doesn't run or even get thin.
I have use White HSG and Many others for PCs and other electronics but ran out one day years ago and have PBG from brake jobs so used that and many time since never bother w/ HSG again. Example: I use it for current PC and AMD 8 core CPU pegged @ 4.3mhz never goes above ~150°F w/ "just" Hyper 212 and One slow fan. Most times runs ~ 70°F all day long. GPU w/ whatever installed by ASUS runs > 100°F even @ idle w/ 2 fans spinning faster.
Even when Hyper 212 moves because how it's mounted... PBG doesn't care unlike most HSG will need re-greasing as has dried out and now "breaks" the joint even moving Fractions of a mm. Knocking a heatsink or fansink around is easy just trying to clean dust inside of vast majority of PC and other cases.
[This message has been edited by theogre (edited 01-26-2022).]
Is standard White HSG. For the amount and package type is a rip off.
PBG can use it on brake parts, as HSG, and more. Like Can use it to keep out "water" from wire joints like ends bolted/screwed to engine and frame because plastic safe and won't wash off easy. silicon oil/grease and most dielectric greases (which are silicon grease) are ok but not as good. Many things included ICM came w/ dielectric greases as HSG but no longer to cut cost for them.
I get small bottles of PBG and last for years because you often use very small amounts even for brake jobs.
[This message has been edited by theogre (edited 01-26-2022).]
Originally posted by Patrick: Ogre, is Permatex Brake Grease much different than Sil-Glyde (which has always been highly recommended for brake use).
Yes Sil-Glyde may contain Silicon oil or solids but has Castor oil "30-60%" by publish MSDS/SDS.
PBG green is >90% SYNTHETIC BASE OILS (TRADE SECRET) by same source.
Castor oil like most organic oils (like corn and other cooking oils) can go "rancid" or otherwise degrade often over a short term. Even in dark cool places degrades just from O2 let alone from Ground Level Ozone in cars.
Plus Sil-Glyde MSDS say... Harmful to aquatic life. Harmful to aquatic life with long lasting effects. but says Clean Water Act and others rules/laws may not apply. ???
I was using Thermalloy 250G (yellow tube) heat sink grease under a 2.8 ICM.
It worked, but it needed to be wiped clean and reapplied as part of an annual tuneup.
When I tried to stretch the maintenance interval, problems arose around 2 years. After 2 years, I had the ignition cutting out, and I found water trapped underneath the ICM (no more close contact between ICM and distributor base).
Originally posted by sledcaddie: Who knew there was so much to learn about heat sink grease? Thanks, Ogre! I will try the Permatex green.
Actually is not much to HSG to know for most cases.
Biggest problem is PC world w/ vendors hyping whatever and users including "expects" believing the Hype.
Like nearly all "Silver HSG" has No Silver in them. Most are Aluminum, Al Oxides and other things w/ carrier oil. Including Current Arctic Silver 5... Zinc Oxide, Boron Nitride, Aluminum Oxide Source: http://arcticsilver.com/PDF/AS5_SDS.pdfAnd still want High $ for a Fraction of 1 ounce.
Meanwhile can get... 2oz Tube white HSG at mcmaster.com for $17 100g(~3.5oz) white HSG at amazon $16 And many other places sell larger packs for > $, often a lot > $
Only thing is often can't use any silicone oil/grease in direct contact w/ silicone chips like many GPU don't have metal covers. Some non-silicone HSG are more expensive.
I use PBG because can use it for indented job and other things and does care if takes Years to Decades to use it. Larger or smaller HSG amounts can separate oil out and go "bad" sitting in the package. Same problem w/ many other "car" grease even some Moble1 syn grease. More so when loaded in most grease guns sitting months to years DIY trying using up a tube. (Big spring can squeezes oil out even if storing normally oil stays put w/ a tube on a self.) Another example, Many have soft tubes of White Grease for cars etc does same thing sitting for months to years. Would do their job but when have little/no carrier oil to letting them flow make it hard or impossible to use...
Originally posted by pmbrunelle: I was using Thermalloy 250G (yellow tube) heat sink grease under a 2.8 ICM.
It worked, but it needed to be wiped clean and reapplied as part of an annual tuneup.
When I tried to stretch the maintenance interval, problems arose around 2 years. After 2 years, I had the ignition cutting out, and I found water trapped underneath the ICM (no more close contact between ICM and distributor base).
HSG won't cause surfaces to loosen or other problems like that.
Iffy screws and/or Dist base can let screws to back out from vibration and heat cycling. Any oil including Carrier Oil in the HSG might make this easier. Many have Black Oxide coated screws there that cause problems too. While that prevent rust, have problems as a Ground. GM has many TSBs to remove the coating or replace the screws.
there is also the dist shaft. removing the whole dist assembly, removing the roll pin from the shaft, and cleaning the actual shaft and making it spin free again. I know mine was pretty sticky when I first pulled it. that stickiness makes heat. after doing that, I never had to replace my ICM again. tho, I did go to a 7730 and coil ack ignition a while later.
I don't have a good explanation for that, but water between the ICM and distributor means that were was enough of a gap that would cause poor heat transfer.
quote
Originally posted by theogre: I use PBG because can use it for indented job and other things and does care if takes Years to Decades to use it. Larger or smaller HSG amounts can separate oil out and go "bad" sitting in the package. Same problem w/ many other "car" grease even some Moble1 syn grease. More so when loaded in most grease guns sitting months to years DIY trying using up a tube. (Big spring can squeezes oil out even if storing normally oil stays put w/ a tube on a self.) Another example, Many have soft tubes of White Grease for cars etc does same thing sitting for months to years. Would do their job but when have little/no carrier oil to letting them flow make it hard or impossible to use...
Usually grease separation is a reversible process. At work we have 55 gallon drums of grease, and sometimes the oil can separate. Stirring the contents with a stick makes it good as new. Some greases seem to separate more easily than others.
Stirring the contents of a grease gun tube may prove to be tricky though.
quote
Originally posted by theogre: Iffy screws and/or Dist base can let screws to back out from vibration and heat cycling. Any oil including Carrier Oil in the HSG might make this easier. Many have Black Oxide coated screws there that cause problems too. While that prevent rust, have problems as a Ground. GM has many TSBs to remove the coating or replace the screws.
You can install the ICM with heat sink compound, and then remove it immediately as a test. If you see the white paste close to the screw hole, you can wipe away and start over again, until you're able to reliably install the ICM without getting heat sink compound on the threads.
I guess I would suggest liquid anaerobic threadlocker for something like this. It won't interfere with electrical conductivity, it will prevent corrosion (assuming the screws were cleaned to begin with), and it helps prevent screws from unscrewing. Once the threadlocker has cured (hours to days), it won't matter if any carrier oil seeps towards the threads.
Originally posted by pmbrunelle: Usually grease separation is a reversible process. At work we have 55 gallon drums of grease, and sometimes the oil can separate. Stirring the contents with a stick makes it good as new. Some greases seem to separate more easily than others.
Stirring the contents of a grease gun tube may prove to be tricky though.
Grease gun tubes are often stable stored on a self. Often for years... Once loaded in a gun, the big spring for 14oz cap or bigger drives out carrier oil and other thin parts out and gun leaks oil on everything and whatever left is often "bad." If you pull the tube can use the paste for somethings but not going thru zerk and other small holes w/ many greases.
Small 3oz cap grease guns can have same problem but have smaller springs so less of this happening but have to keep in plastic bag to stop drips staining whatever touches.
Many have White grease and more in soft plastic tube that separate and knead the tube can mix the stuff so works ok again. If those leak oil out because cap is loose or tube w/ small hole on sides, the product is often a HAZMAT waste.
Examples: I had a very old silicone/dielectric grease in soft metal tube and got a very small hole and leaked oil out and then just solids and won't even flow to push out of the tube. 30+ year old white grease in plastic tube separate oil but oil stay in the tube so can use it but messy. 14oz tube Mobil1 in a gun leaked red oil on everything until gone then grease paste left won't even flow thru the gun.
5 - 55gl bulk product often won't care if separate some. If separates a lot, try "paint" mixer and drill. Make sure can reach bottom of container where most systems pick up the product. Many bulk systems have mixers build into them for product likes to separate quickly.
there is also the dist shaft. removing the whole dist assembly, removing the roll pin from the shaft, and cleaning the actual shaft and making it spin free again. I know mine was pretty sticky when I first pulled it. that stickiness makes heat.
That is one of several reasons its recommended to replace the pickup coil when replacing an ICM, because it forces the overhaul/maintenance of the distributor shaft.
[This message has been edited by Skybax (edited 01-29-2022).]
I just received my new GM ignition control module (from Rock Auto). The box shows that it is made in U.S.A. It also shows the date of 1995. Maybe this is a NOS from roughly, the Fiero years.
