85 GT without A/C. I have been having ignition control modules problems. First it stopped twice while driving and then restarted after a short cool down. The car did not get overly hot according to temp gauge. I replaced the module, which was a few years old but had low miles. I take the car on a 60 mile trip to Lititz and everything runs fine until on the return trip I’m almost home and In traffic for awhile. Temp gauge is about mid-range and I’m coming out of traffic light fairly hot against a Mustang and it shuts off again. Ooops… a little embarrassing as I coast to the shoulder. I put the flashers on and sit there five to ten or so and it restarts. I’m was on Route 100 N of Pottstown, PA and a pristine white 88 GT drives past without even a beep let alone stopping—what’s with those fastback GT drivers? Hmmm….. maybe jealous that I have less weight and 140 bhp to their 135? (Just quoting published info here)

All three times I was in traffic the temp gauge rising but no higher than mid-range. It does continue to climb a little after failing before it starts to cool again but never very near the red area. The cooling fluid level is good BTW and while driving never goes above quarter range on the gauge.

Pontiac Kid was at the house helping with a project and showed me the trick of grounding the temp sensor switch to check operation of the coolant fan and the engine fan. They both work but the switch had seen better days. So I got a new coil and new fan switch, just in case since they were original. Once installed and my heat shields repainted, everything is pretty again.

I drive 26 miles to work every day. The first 20 are highway and the last 6 are in traffic. The first time out, the car gets 24 miles and shuts down at almost the same location it did twice on the old module. OF course all three times on the return trip home at midnight with lower ambient and no traffic the car runs fine.

It doesn’t seem as if the coolant fan or trunk fan is running when this happens and I have to sit, although the car does not overheat according to the gauge. Since it’s not an A/C car the fan(s) cannot be turned on by using the A/C to avoid overheating. I will put in another new module, but unless the last one’s failure is coincidental it’s just going to happen again. Any ideas?

------------------
Notchbacks RULE

"Let a man drive a Fiero and he'll own one.
Teach a man to fix a Fiero and he'll own eight....errr...nine."

I ended up installing a new distributor (a Cardone from auto zone) which included a new ignition modual, plus a new coil in my 88GT I find the car runs fine now. The replaced items were just old and I was just replacing all the ignition components. It was less that $200 for all the stuff. You could hard wire to keep the trunk cooling fan for distributor and alternator on all the time.

repeat module problems likely is:
Bad brand in replacement parts.
Bad ground(s). Module has two ground and both must work.
Bad pick up coil.
Bad ignition coil. (Coil Frame need good ground to...)
Bad dist cap and/or rotor.
Iffy spark plug and/or plug wires.
Tach Filter is bad.
Not installing parts right.

Also likely has a coolant problem.

See cave
HE Ignition in engine general section
read all coolant section


------------------
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)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 10-26-2010).]

Thanks for the info Ogre. Everything, plugs , wires, cap, rotor only have maybe 5k on them. The coil is new of course and installed correctly and the fan switch is new. Cooling system including water pump is good and doesn't run hot. Perhaps the topic should have been titled 'fan problems'. The initial module that started cutting out was a less than 5k ACDelco. The replacement HEI module I got was a Standard and the next one going in is also a Standard. The problem seems somehow related to heat. I said, I don't think the fan is running even when the temp starts to rise after shutting the car off. It seems as though the fan should kick in at this point like it doe's on my '93 Cavalier 3.1 when it gets tomid-range on the gauge in someway causing the module to fail temporarily.

Pick up coil or Ignition coil?

Have you tested it with a meter?

The ignition module/coil combination should still work even at the extremes of the temperature gauge although it does seem likely that a slight overheating problem also exists. Probably the pick-up coil is going bad at temperature (or you forgot the white heatsink compound on the module base when you replaced it) or the new module is bad (it happens). Next time it quits (if you are somewhere safe to do so) I would check a plug to see if the spark has truly gone - it would eliminate any fuel problems. You did not say if you were getting any codes at all. Although very rare, an intermittent ECM (computer) is a possibility also of course.

I'll be kinda blunt. I hope it's ok but if not you can just call me nasty names and give me a negative rating.

1 - You have made an assumption that your ignition problem is heat related. IF you had an iffy ICM it COULD be heat related. A good ICM will operate at all normal operating temperatures PLUS overheating. I doubt you have two ICM's that have the same heat related problems. I am assuming you are using thermal paste under your ICM. Bottom line, my advice is to look elsewhere for your ignition problem before looking back at your ICM.

The distributor is located a ways from the engine block, and while heat will travel along the distributor base, most of the distributor is air cooled. The air temp around the distributor has more of an effect than engine temps in my estimation. The distributor has little knowledge of exactly what the coolant temperature is. If your driving down the highway with a lot of air circulation in the engine compartment I doubt there is much coorelation with coolant temp and dist temp.

2 - There are more than one thing that can kill your ignition. Ogre mentioned a few of them. One he didn't mention is power. If the pink wire on your coil looses +12v there is no power to run the ignition and no spark.

3 - The other big thing I see doing this is pick up coil. Have you tested it with the following test



4 - The problem in troubleshooting this is the trouble doesn't occur frequently and long enough to troubleshoot too well. If the pick up coil, and the ignition coil pass the test, then the thing is you are going to have to bring a meter and a test light along with you and hope it fails long enough that you can troubleshoot it. Assuming both coils passed the previous tests the first one I would look for is power. Then again test both coils when the trouble is happening. Hopefully you will find the trouble.

Good luck and let us know how it goes.

quote Originally posted by Fierobruiser: I don't think the fan is running even when the temp starts to rise after shutting the car off.

It's not wired to do that on a Fiero. There is no power to the fan when the engine/car is turned off.

As others have stated, I suspect your problem is with a failing pick-up coil (not the ignition coil).

Thanks for the replies and hints/tips.

Phonedawgz- Thanks for the distributor info, saves having to look it up in the shop manual. I don’t know what the tach does; car shuts off, look at the tach and zero. I didn’t notice if it indicates anything while cranking. I’m thinking thermal because that is what usually kills the HEI. What is really mysterious is it’s almost predictability. Three times thus far with both an (older) and a new module it dies at the almost exactly the same place in Emmaus, PA. The engine is at operating temp and then starts to heat up some in traffic to about mid range and just dies. I have noticed that it gives one little miss a few minutes before it just stops. 5-10 minutes later at most it fires back up runs perfectly. Seven hours later leaving work there’s no traffic at all, temps a little cooler and it runs fine for 50 minutes headed home.

Patrick - I would think the tach filter or pick-up coil would be a more erratic problem; although I can pull the distributor and replace it and the o-ring even though the engine only has 46k on the clock.

All - When I replaced the module. I used the grease provided with it. This was a whitish/clear substance and I thought that it was not correct, so I went to about 4 different auto stores (don’t remember if I went to the dealer) looking for, what I remembered from previous modules, to be a white hi-temp grease to use under these and all anyone had was ‘dielectric grease’ which I have always used for electric connectors. This may be part of the problem. If you know who makes it, let me know. I’d like to use the right stuff before I waste another module.

Anyway, I’m just going to go start it up and let it sit in the driveway and see if the fan comes on before it gets too hot or shuts off and see what the tach does. The HEI ought to test good until it quits, but we’ll see.

[This message has been edited by Fierobruiser (edited 10-26-2010).]

Just for info, I always buy Autozones modules. There $25 (unless theyve gone up in 10 years) and a lifetime warranty. Ive had to replace one twice. I also got an OEM AC Delco one for $89 that everyone says is better, that didnt last a week or two and dealer said no return/exchange on elec parts.

quote Originally posted by Fierobruiser: Patrick - I would think the tach filter or pick-up coil would be a more erratic problem; although I can pull the distributor and replace it and the o-ring even though the engine only has 46k on the clock.

What can I say, it's common practice among long-time 2.8 Fiero owners to replace both the ignition module and the pick-up coil at the same time as faulty pick-up coils appear to eat ignition modules.

quote Originally posted by Fierobruiser: When I replaced the module. I used the grease provided with it. This may be part of the problem. If you know who makes it, let me know. I’d like to use the right stuff before I waste another module.

Go to any computer store and buy heatsink compound used with CPUs.

quote Originally posted by Patrick: What can I say, it's common practice among long-time 2.8 Fiero owners to replace both the ignition module and the pick-up coil at the same time as faulty pick-up coils appear to eat ignition modules..[/QUOTE [QUOTE]Originally posted by Patrick: Go to any computer store and buy heatsink compound used with CPUs.

Well I'm a long time Fiero owner and have changed out 4 modules now and the others all lasted without doing the pick-up coil, but it can't hurt. Thanks I'll try Radio Shack.

[This message has been edited by Fierobruiser (edited 10-26-2010).]

While you're on the topic, read the file pasted below:

Your’s could be a common problem and don’t cost anything to check.
Try this:
Watch the tach when cranking if it don’t move you're not getting pulses from the distributor. If so, it could be a faulty module in it or more likely simply corroded connectors at the base of the distributor. Reseating those connectors a few times could clean the pins some and also do the same to the connectors on the coil etc. These cars are old, and old connectors corrode. Such can also manifest itself as intermittent misfires, and engine cutouts.

BTW: lots of folks keep replacing modules and coils thinking they are bad because the new ones FIX the problem, when in actuality the fact that they simply unpluged the connectors and repluged them into the new unit cleaned the contacts enough to make it work again, at least for a while. It's smart, to replace those old connectors with new ones.
BTW: Cliphouse has those connectors

------------------
[IMG]




trueleo.com
RSpiderII@aol.com

Well Dielectric Grease is used to keep moisture out of electrical connections. You should use it on any electrical connections that may be subject to moisture (all exterior lighting, and most engine connections. You should also use it inside the spark plug boots and dist cap connection boots. It's great to use on your trailer hitch wiring plug, but keep it capped so it doesn't get wiped onto the stuff in your trunk.

Thermal Paste - is designed to help the transfer of heat from one component to the other. Thermal paste is not dielectric grease. Thermal paste should be used under the ICM to help keep it cool. The inside of the distributor doesn't really see much moisture and even if it did, the thermal properties of the thermal paste is what is needed there.

If you do have a multi meter you would be well advised to try the pick up coil test. Yes it might not show as failing till it's warmed up/hot, however you just might also find it fails now. It's fairly easy to do the test with a Fiero (easy to reach dist). Make sure you wiggle the wires like the diagram says to see if there is any iffy connections there.

Have you thought about a route that doesn't include Emmaus, PA?

quote Originally posted by Francis T: While you're on the topic, read the file pasted below: Your’s could be a common problem and don’t cost anything to check. Try this: Watch the tach when cranking if it don’t move you're not getting pulses from the distributor. If so, it could be a faulty module in it or more likely simply corroded connectors at the base of the distributor. Reseating those connectors a few times could clean the pins some and also do the same to the connectors on the coil etc. These cars are old, and old connectors corrode. Such can also manifest itself as intermittent misfires, and engine cutouts. BTW: lots of folks keep replacing modules and coils thinking they are bad because the new ones FIX the problem, when in actuality the fact that they simply unpluged the connectors and repluged them into the new unit cleaned the contacts enough to make it work again, at least for a while. It's smart, to replace those old connectors with new ones. BTW: Cliphouse has those connectors

Thanks Francis. I usually try to avoid replacing connectors by using Dielectric grease for connectors. It prevents corrosion and is conductive. Actually the only connector I have tried to replace with new was the one to the v6 automatic neutral safety switch and couldn't find one. Does Cliphouse handle these too?

If you do replace the pick up coil, you will end up having to take out the distributor.

quote Originally posted by phonedawgz: Well Dielectric Grease is used to keep moisture out of electrical connections. You should use it on any electrical connections that may be subject to moisture (all exterior lighting, and most engine connections. You should also use it inside the spark plug boots and dist cap connection boots. It's great to use on your trailer hitch wiring plug, but keep it capped so it doesn't get wiped onto the stuff in your trunk. Thermal Paste - is designed to help the transfer of heat from one component to the other. Thermal paste is not dielectric grease. Thermal paste should be used under the ICM to help keep it cool. The inside of the distributor doesn't really see much moisture and even if it did, the thermal properties of the thermal paste is what is needed there. If you do have a multi meter you would be well advised to try the pick up coil test. Yes it might not show as failing till it's warmed up/hot, however you just might also find it fails now. It's fairly easy to do the test with a Fiero (easy to reach dist). Make sure you wiggle the wires like the diagram says to see if there is any iffy connections there. Have you thought about a route that doesn't include Emmaus, PA?

Thanks for the help Dawg. My suspicions have been confirmed about the Dielectric grease even though the parts stores don't know the difference. The 'stuff' with the new module doesn't look like paste.

Thanks also for the helpful videos. Might be even more helpful for others. I've pulled distributors and replaced o-rings before but never a pick-up coil.

[This message has been edited by Fierobruiser (edited 10-26-2010).]

quote Originally posted by Fierobruiser: Three times thus far with both an (older) and a new module it dies at the almost exactly the same place in Emmaus, PA.

quote Originally posted by phonedawgz: Have you thought about a route that doesn't include Emmaus, PA?

Heh heh, that's funny...

quote Originally posted by Fierobruiser: Thanks Francis. I usually try to avoid replacing connectors by using Dielectric grease for connectors. It prevents corrosion and is conductive. Actually the only connector I have tried to replace with new was the one to the v6 automatic neutral safety switch and couldn't find one. Does Cliphouse handle these too?

They may have that one too. Before I retired I was a computer hardware engineer -the ole main frames and minis DIGITAL mostly- perhaps 30% or more of the fixes were jsut cleaning Circuit board edge connectors with erasers. It's amazing what a lil corrsion will do to electronics. Intermitant connections and what not. Sadly most gearheads just dont look for that to be the real problem, they just want to swap out parts and then think they fixed it when they just brought a lil more time by plugging in the new unit which cleaned the connector.

Great example:
Last week I had a coil go bad an MSD too, yup it was the coil not the connectors -they were all new- and I got it running again with a suposedly-BAD stock coil I got from a friend a long time ago -he wasted his on money on new one thinking he had bad one. Moral: Don't trash any old ignition parts until you try them a 2nd time.

quote Originally posted by Fierobruiser: Thanks Francis. I usually try to avoid replacing connectors by using Dielectric grease for connectors. It prevents corrosion and is conductive. Actually the only connector I have tried to replace with new was the one to the v6 automatic neutral safety switch and couldn't find one. Does Cliphouse handle these too?

Dielectric grease is non-conductive. It keeps the air off the metal so it doesn't corrode but it doesn't electrically connect the metal pieces. The metal itself has to make metal to metal contact for that to happen.

quote Originally posted by phonedawgz: Dielectric grease is non-conductive. It keeps the air off the metal so it doesn't corrode but it doesn't electrically connect the metal pieces. The metal itself has to make metal to metal contact for that to happen.

+1

However; There are greases out there that are specifically formulated to be highly conductive. I've used those on all my ground to frame connections and ground to engine connections. Never had a bad or poor ground problem.

Quote from Wikipedia:
"A dielectric is an electrical insulator that may be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric polarization."

"However; There are greases out there that are specifically formulated to be highly conductive. I've used those on all my ground to frame connections and ground to engine connections. Never had a bad or poor ground problem."

Care to shed some more light on this type of grease, i'd be interseted in something that prevents corrosion and intices better conductivity.

Information on conductive greases. Sure thing, there are a couple of links below (my grease came from Digikey). The grease I have used is a silver conductive grease. In simple terms it's a silicone based grease blended with silver dust.

The bad news: Silver is expensive so grease blended with silver dust is VERY expensive.

The good news: A little bit of the grease goes a long, long ways. So you don't need very much. It's best to apply a small amount and spread it around with a small artist brush. I've had the same container and brush for years.

Also be careful where you use it because it truly is highly conductive and it will get everywhere if you use to much (just like never sieze compound which always seems to get all over everything before you know it). I would not recommend using it multi pin automotive electrical connectors unless you are extremely careful (if not you will short stuff out!).

http://parts.digikey.com/1/...-syringe-cw7100.html

http://www.2spi.com/catalog...grease-techdata.html

http://www.hmcelectronics.c...1/Chemtronics-CW7100

http://www.grainger.com/Gra...ductive-Grease-1UYE2

[This message has been edited by W Scott (edited 10-28-2010).]

It's fine to use dielectric grease on your ground connection. In fact it's a good idea. Where the metal touches metal the grease is squeezes out and you have a gas tight seal anyways. Where the metal isn't tight together the metal surfaces are protected from gasses and thus corrosion

Listen to Phonedawgz. I was having the EXACT SAME PROBLEM. My pickup coil was bad. Easy to replace, just pull the dizzy, mark your spot so you dont lose it, knock the pin out, disassemble and reassemble with new pickup coil. (Removing the pin is the hardest part.. all my punches were too big, so i had to use the buddy craid drill bit method.) $7 part.

I did a tune up on my car in May, and when I put the cap back on the dist., I crushed the pickup coil wires. Look there. Also check your connections where the hook onto the dist... (The 4 prong connector especially) Run your tests from those connections all the way to the ecm connection on the inside of the firewall with your multimeter. You could have a short somewhere along the way.

I'm about to rebuild the dist. in my Indy.. that one looks like fun. Good luck, let us know how you fixed it so we are not in the dark.

Did you test the bad modules? O'Reilly's (used to be Murray's here) and probably most other auto parts stores will test things for free.