I was driving to work this morning on the highway cruising at 70 MPH listening to the subtle hum of the Borla when...SILENCE!! The tach read zero. I put it in neutral and attempted a rolling start, but it just sputtered and died. Luckily, traffic was light and I was able to sidle over to the breakdown lane (how quaint). As I sat there mulling the possibilities, I tried to restart the engine with the same result; it tried to engage then sputtered and died. Subsequently, I called roadside assistance and got the ball rolling in that direction. As I was waiting for my tow, I tried again to restart and this time I was successful. I turned the ignition off and tried again to no avail. in the forty five minutes prior to the arrival of the tow truck, I tried a couple more times with no luck. After I got the car home; it started. Now, I'm kind of leaning toward the fuel pump. This is a 3.4L with the 4T60. I have the TCC crimp spliced into the fuel pump relay per the South Coast Fiero method. Traffic was to loud to hear if the fuel pump was engaging. I am pretty sure it's not the ICM (though not positive) although I have experienced that on more than one occasion. I have tentatively ruled the ICM out due to the sputtering and dying issue. If anyone has any other thoughts I would be glad to hear them.

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Peace!!

B2 OUT!!
86GT 3.4LProject

I'd sure check your fuel pressure. As I read your post my first thought was fuel pump or fuel related.
I've had pumps die in a way the I could start a couple times until it died completely. Could even be split coupler in the tank.
Does the tach twitch when you crank?

It sounds like classic ICM to me.

Dodgerunner, I will mess with it today. The problem is that right now it will start. I just hate to chance this happening on my way to work. It's a 35 mile drive an I only have so many sick days. Mabey I'll just change the ICM and the fuel pump and give it a go.

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Peace!!

B2 OUT!!
86GT 3.4LProject

Very first thing to do is see if its got spark. If not everyone should carry a spare ignition module and changing tools. Anyone with a Fiero and no spare is asking to get stranded sooner or later. I also carries spare coil at all times.

When either goes out, car does exactly what you say. Its like turning the key off.

Take note of the recent thread about thermal paste. If the stuff you used was clear it is the wrong stuff....and may actually inhibit proper grounding, because it is non-conductive grease.....

https://www.fiero.nl/forum/Forum2/HTML/117983.html

[This message has been edited by Gall757 (edited 08-09-2011).]

Sounds electrical. Fuel problems tend to burble to a stop. It is not out of the question but before pulling the gas tank to replace the fule pump I would check the Ignition module and coil.

I think I have replied to 6 threads like this already, but my situation sounds similar.

My car broke down at Home Depot after I just drove it there and came back out to leave. It wouldn't start. It was only giving 20 psi of fuel pressure.
I pulled it home. I then replaced the fuel pump, it ran for a week, then did it again, I then replaced the ICM and then the ECM.

On a last ditch effort I added a Ground line from the Negative terminal on the battery back to the Intake to ground the engine and it started right up and has run great since.

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86 Fiero 2M4 Silver, and 86 GT

[This message has been edited by jwrape (edited 08-09-2011).]

I vote ICM as well, mine died like that too....in the middle of nowhere. The replacement ICM left me stranded too, but after a tow home the car would start just fine and act like nothing happened. Like everyone else, I'll say check the ICM, pick-up coil, and anything else that might cause an ignition problem. It might be time for an ignition overhaul.

If the tach died before the engine stopped turning then you have a problem with the primary side of your ignition system.

ICM
Pick up coil
Ignition coil
Power to the ignition coil. Check for +12v on the pink wire at the coil

Connections between the ICM and the ignition coil. Check for +12v also at the distributor end of the harness. To check the white wire unplug the harness from the ICM. Attach a spark plug laying on the engine to the high voltage ignition to distributor wire. Now with the key on insert a paperclip into the white wire end of the cable and tap it on an engine ground. You should get a bright blue spark from the plug.

If the ignition primary died, the ECM won't fire the injectors. Check for spark before looking at fuel. The ECM injects fuel based on ignition pulses.

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Most parts stores will test ICM modules for free. If the below tests show good, take out the ICM and run it down to the parts store.
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Here is a detailed test of the ignition coil and pick up coil assuming you know how to run an ohm meter.

Make sure you use thermal paste (THERMAL PASTE not dielectric grease) under the ICM or it will heat fail prematurely.

Make sure your coil and spark plug wires are not of high resistance or they will shock kill your ICM and it will fail prematurely. No more than 10K ohm per foot for spark plug wires.

If you replace your ICM, you should also replace your ignition coil. Bad insulation on your ignition coil can shock your ICM and it will fail prematurely. If your ICM failed, it might have failed because of bad insulation on your ignition coil. It's cheaper to buy an ignition coil than a second ICM and ignition coil.

Also - yes the picture shows the distributor removed while testing the pick up coil - but that is not needed to test. Removing the distributor is needed to REPLACE the pick up coil.

[This message has been edited by phonedawgz (edited 08-09-2011).]

Ok, as I stated earlier; when I got the car home, it started. So all of the perscribed checks mentioned would check normal. What I did do is, replace the pickup coil (26 years old) and I am in the process of replaceing the ignition module. The symptom was simply Cruising... then Silence. No tach, no stumble, no nothing. Once I got pulled over it acted like it wanted to start but stumbled and died. 15 minutes later it started. I turned it off and tried to restart, nothing, it just turned over and over. Towed home, got it on the ground and voila! its starts.

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Peace!!

B2 OUT!!
86GT 3.4LProject

Sounds like the module is working till it gets hot enough to fail. The same thing happed to me one time.

Replaced the module, drove the same rout past the breakdown point and came back with no issues. So, to those of you who said it was the module thanks again. I was convinced it was fuel related due to the stumbling when I tried to start it. So I stand corrected. It seems to idle smoother with the new pick up coil.

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Peace!!

B2 OUT!!
86GT 3.4LProject

Even though that one has failed, you might want to put it back in just to see if it will start the engine. If it will, remove it and throw it into the trunk. It could be what gets you off the road and home the next time.

It does and I did. After closer inspection it may have actually been a case of too little heat sinking compound. I mean, it was there; but it was very lightly applied. With the new module came a packet of the compound and I made sure to use it generously and wipe of any excess that squeezed out. There wasn't much of that though.

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Peace!!

B2 OUT!!
86GT 3.4LProject

UPDATE:: I made it to work this morning with no problem. Save for the fact the 4T60 is now being screwy with the overdrive. It will shift all gears and then hovers somewhere in the overdrive range. I was taching just over 2100 @ 70 MPH, now it varries between 2200 and 2600 depending on the load. Any ideas here??

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Peace!!

B2 OUT!!
86GT 3.4LProject

You can only accurately test the module while its hot right out of the car. Ive had a few known bad ones tested, that tested fine at the parts store.

It sounds like the torque converter is not going into lockup. Perhaps a bad torque converter control solenoid?

quote Originally posted by rogergarrison: You can only accurately test the module while its hot right out of the car. Ive had a few known bad ones tested, that tested fine at the parts store.

Are you sure about that? I had one tested at an Advance Auto, and it got hot while testing. Hot enough that I was concerned over it being damaged from the tester.

quote Originally posted by Formula Owner: Are you sure about that? I had one tested at an Advance Auto, and it got hot while testing. Hot enough that I was concerned over it being damaged from the tester.

just ask them to run the test about 4 or 5 times in a row, it will get hot enough to test accurate

OK, I need to revisit this issue. It is doing the same thing.....AGAIN!! Here is the symptom(s); I drive to work everything is smoothe and car couldn't run better. It just quits, silence, nothing. Tach is at zero and coasting to the side of the road and...restart on its own. Drive another 25 miles and all is well then, it quits, same thing. Coast to the side, try a couple of times to no avail. Sit for ten minutes and it starts, but it stumbles as it does like it's flooded or having a hard time getting gas. While pulled to the side I checked the shreader valve for pressure and there is pressure, turn the key on and I can hear the fuel pump. don't have any meters or tools with me to check voltages.

This is a new ICM and pick up coil and ignition coil. Could I have gotten a bad ICM? I got it at AutoZone and not sure who makes them for Duralast. Should I go to my local AC Delco store and get an OEM ICM? This is getting very frustrating.

One more thing; This is a 3.4 upgrade. Just about everything is new. When I went back with the motor I didn't install the heat shields. Could I have toasted the ignition coil? I know that its been getting real hot. this past week I put the heatshield on around the IC and ICM. Could I have been to late??

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Peace!!

B2 OUT!!
86GT 3.4LProject

There are a few possible items. You could have an intermittant contact in one of the harness connections, or a thermal fault in the ICM. I would check each harness connection by opening it up, checking the pins and sockets on both sides and spray electrical contact cleaner in there and then reassemble. If you suspect the ICM is going into thermal shutdown, you can remove it and take it to an auto parts store that tests them for free and get their results of the test. as was suggested above, have it run multiple times to build some heat. it would be worth swapping modules for a known good one to see if the problem persists.

[This message has been edited by Joe 1320 (edited 09-01-2011).]

Did you put plenty of the heat sink paste on the module? I run the GM modules in mine and they seem to be a little better than the aftermarket ones.

I post this file often for problems like yours:


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


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trueleo.com
RSpiderII@aol.com

[This message has been edited by Francis T (edited 09-01-2011).]

We keep one (genuine GM only) in our Fieros at all times. In 15 years we've used the spare module only twice, but like seat belts we don't leave the driveway without it. It controls both ignition and fuel injectors. Clean and reinstall the proper heat transfer greese regularly because it gets crappy over time.
Drive robustly with confidence.

Yellow

This is a new ICM and I used ALL of the heat sink compound that came with it. Was it enough? I'm not sure. Francis T Mentioned the connectors and that is a good place for me to start. two of the four connectors between the coil, the ICM and the harness have broken holding tabs (the tabs that lock the connector to its receptical. That may be part of the problem. Also, though I haven't inspected them real thouroughly, the connections seem to be free of corrosion and dirt.

Back tio the ICM, I plan on getting a new one from the Delco parts house here locally, I carry a spare in my trunk (my old one), but what about the heat sinking compound? Is there a viable source for this stuff? LMK

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Peace!!

B2 OUT!!
86GT 3.4LProject

You can pick up a small tube of heat sink compound from any Radio Shack for just a couple buck.
Any electronic supply shop will also have it but they generally have larger tubes that would last you a 100 years and cost more.

http://www.radioshack.com/p...sp?productId=2102858

[This message has been edited by Dodgerunner (edited 09-01-2011).]

Non GM ICMs are junk.

I hate to generalize, but I have seen it too many times.

I have had nothing but problems with anything other than AC Delco ICM - once I decided to spend the extra coin, never had the problem again.

I am assuming that this is the unit you are refering to? http://cgi.ebay.com/ebaymot...&hash=item56408fbcbc Think I'll skip on down and get one. BTW, is that silicone grease that comes with it the right stuff??

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Peace!!

B2 OUT!!
86GT 3.4LProject

I'm not sure if the part is any different but it has a different part #.

http://cgi.ebay.com/ebaymot...meZSTRKQ3aMEWAXQ3aIT

Just make sure the goop they give you is not clear.....if it is clear it is not the right stuff.....the site URL here does not send you any grease...just the ICM.

[This message has been edited by Gall757 (edited 09-01-2011).]

Ok, $100.00??? Really? Man, there is just no gett'n lucky.

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Peace!!

B2 OUT!!
86GT 3.4LProject

Where was that? Autozone?

Nope, that was at the AC Delco parts house here in southern Nevada. I found it for less than half that on E-Bay for the same OEM product. OUCH!!

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Peace!!

B2 OUT!!
86GT 3.4LProject

Anybody have opinions on this? Just wondering if this is better than the stock unit.



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Peace!!

B2 OUT!!
86GT 3.4LProject

[This message has been edited by BAM-BAM (edited 09-02-2011).]

quote Originally posted by BAM-BAM: Anybody have opinions on this? Just wondering if this is better than the stock unit.

Personally I wouldn't mess with it. Go with a GM ICM and be done with it. That might not be a bad ICM to keep as a spare though.

Sorry, I can't let this die. I think I have got this down to the component that is of issue in this case and it effects the ignition (or is it) in the same manner as a bad ICM. On the coil there are two connectors, one comes from the ICM and the other goes back to the harness and the tach filter. I believe my issue is with this second connector or more, the wires coming off of the connector. my connector has it's retainer clip broken off and is just "plugged" in. Also, the wires are smashed down on it pretty flat.

Today as I drove the car on a 70 mile round trip, it cut out on me 6 times. On the fourth round of this garbage I decided that while I was waiting I would study the ignition system and look for anomolies. I found that both harness connectors have broken retainer clips and that the wires on the afore mentioned connetor were smashed flat. I decided to ensure that the connectors were in tight; nothing. then I decided to neaten up the smashed wires and it started then died. I messed with them again and it started and I drove about four miles and it cut out again. I got out messed with it for another minute or two and it started got about a quarter mile and died. I keep messing with the wires off of this second coil connector and it seems to help. I'm thinking that by replacing this connector I will solve my problem. It would explain why the tach dies and it kills the fuel pump.

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Peace!!

B2 OUT!!
86GT 3.4LProject

Is all this happening with a new ICM?....

Yep, that would be correct. Gall, as you are more than likely aware, the connector on the coil (grey one) is the return to the ECM and the tach filter. I assume that this is what sets the injector pulses. As such, if there is an intermittant interruption in the continuity of these wires, then it would inhibit the injectors and the tach and bring the whole works to a stop. Someone please correct me if I'm wrong.

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Peace!!

B2 OUT!!
86GT 3.4LProject

[This message has been edited by BAM-BAM (edited 09-03-2011).]

I have a spare pigtail harness (coil to ICM)......if you think it will help I'll mail it to you. I also have a few used ICM's lying around.....LMK if I can help.