You read it right, this beast is eating my ICM and or coil. I noticed my ICM has a damaged harness connector. The connector to the coil seems to be fine. The ignition power to coil on pink wire is 12volts and steady. But as soon as I go to crank the car it doesn't want to start. I know I have fuel pressure, pump turns on, I just have no spark at the distributer or at the coil.
It very well could be it's damaged right where BLK/RED and TAN/BLK go into the connector. I would assume this causes a jump in electrical signal since the terminals are next to one another and the plastic around them is gone and metal terminal is exposed.
So did I just answer my own question haha, I'm a bit tired I racked my brain on this all day. I also ohm tested my coil, primary is 0.3ohms and secondary is 9.980 ohms which is in good spec correct? I had my ignition control module tested 7 times before I put it in and it passed all time. So I assume yes I answered my own question 😂
LOL Sounds familiar. When I bought my car, the plastic connector where the pickup coil leads clip onto the module had long since broken and fallen off. So it was just the two wires with the terminals on the ends, press-fit onto the module terminals. Hardly a confident connection!
Just FYI, the black wire with the red stripe is the ignition ground. If there's a bad connection on that wire, you'll get weak or no spark. Also, the tan wire with the black stripe is the bypass wire. If that connection is broken, it shuts off the ECM timing advance. So the engine won't accelerate very well.
So yeah... having bad connections on those wires can really mess things up. If worse comes to worst, you can buy a new pigtail and splice it in. I think this one would do the trick: http://www.repairconnector....epair-Connector.html
Or you could search for one in a salvage yard. It should be a pretty common item. That style of connector was used on many GM cars with HEI distributers, and many GM idle air valves.
LOL Sounds familiar. When I bought my car, the plastic connector where the pickup coil leads clip onto the module had long since broken and fallen off. So it was just the two wires with the terminals on the ends, press-fit onto the module terminals. Hardly a confident connection!
I had one that crumbled apart, so I used some heat shrink tubing and slipped a piece over each wire lead to insulate them. I just had to make note of which wire went to which side of the ignition module each time I had occasion to disconnect them. Never had another problem.
The crumbly connectors definitely sounds familiar to me, too. And a lesson in "leaving well enough alone."
My car is low mileage, and I got the bright idea to replace the ICM out of an abundance of caution. After all, its a 2 minute job, right?. Did my research, and paid extra for the ACDelco. Then, went and bought high quality heat sink grease.
Only for that stupid connection to break apart when I went to remove the old ICM. Rather than rebuild or get creative with the connector, I ended up just upgrading to a new distributor. And, of course, the first new distributor I bought had a very suspect connector, so I had to send it back and get another.
All's well that ends well, but what a PITA just for a preventative measure.
Unplug tach filter and leave it unplug til you maybe find any other things wrong. See my Cave, HE Ignition
------------------ 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)
I bought a new pigtail connector today, now just need to wire it up. My first question, would my ICM need to be replaced you think if it had signal jump in the pins? Secondly what would unplugging my tach filter do, and if I did where is it located?
I'm not sure if that would damage the ICM or not. But you'll find out soon enough.
The tach filter should be a little grey cylinder sitting next to the ignition coil. (see photo below) If it's been deleted, then you can rule out a faulty tach filter.
In case you're wondering, the tach filter smooths out the movement of the tachometer needle. If the tach filter is deleted, it shouldn't hurt anything. But your tachometer might be a little twitchy.
And yes I found out my ICM is bad, so I'll need to be getting a new one (oh the boys at Autozone hate me😂) also yes my tachometer is a bit jumpy at times. Would the tach filter missing show a high idle like I have been experiencing since I have owned the car or no?
And yes I found out my ICM is bad, so I'll need to be getting a new one (oh the boys at Autozone hate me😂)
The Boys at AutoZone refused to honor the warranty on my brother's ICM after he returned several within a few days. They tested each one as he returned them and they were bad. They said they were losing money and wouldn't replace any more.
The Boys at AutoZone refused to honor the warranty on my brother's ICM after he returned several within a few days. They tested each one as he returned them and they were bad. They said they were losing money and wouldn't replace any more.
That's what they told me today, but I said back to them how do you know they weren't bad when you gave me them? They never tested them for me until today, they just kept swapping them out. To be fair Duralast isn't a bad brand, I just had a faulty pigtail. Now I gotta chase this intermittent misfire in a bad wire or plug. It's hard because it misfires every once and awhile an not long enough for me to trace it by pulling wires. I would use a scan tool to measure current flow but I don't have one.
Last time I checked AZ uses Wells as store brand ignition parts. Wells like Standard is a very old brand and works good.
Repeatedly frying ICM is most likely cause by other ignition part(s) bad and/or install poorly. I've seen many DIY claiming "icm sucks" are most wrong and does not fix the root cause then whine when another ICM dies.
Examples: Bad plugs wires and other HV parts can cause HV "feedback" to the HEI and DIS coil(s) and other low volt parts and quickly or slowly kill them. See http://www.wellsve.com/vide...gnitiontraining.html HEI often have similar problems killing ICM. (Wells DIS coils have extra insulation to prevent HV flash over when car has bad plugs/wires.) All HEI coils need good ground to the engine. Iron frame w/o this will cause problems and often kill ICM etc. Means HEI coil w/ crap/missing mounting screw etc are large problems. (Many idiots throw away ground terminal for HEI coil on cap for V8 and wonder why they have problems...) HEI ICM uses One Mounting Screw as a Ground. Crap screw then expect ICM death.
Originally posted by Gall757: You could be killing ICMs by pulling the spark plug wires with the engine running.
Yes. Pull any HV wires on a running engine is a good way to kill the coil(s), ICM, etc. Yet Haynes and others still say pulling a plug wire to test whatever... Is same BS telling car will still run by discon the battery but causes many problems and can even kill ECM/PCM etc.
I don't pull the wires alone, I use a test light to ground and let it grab that spark listening for rpm drop. But like I said it's hard to catch it because it does it every once and awhile. It has to be in the back 3 spark plugs closest to the window. Because the front 3 are new they are Champion spark plugs, not sure what type though. I took a picture of the 3 in the back because I couldn't see them, they are slightly rusty not bad though, there is no gunk around them either. I'm just going to change all 6 with AcDelco copper plugs.
[This message has been edited by FieroChicken86SE (edited 01-24-2018).]
I'm not familiar with Fieros or any car for that matter. This is the first car I have ever fixed. It's been a hassle and learning curve for me. But I'm slowly making progress. I have learned a ton about cars, and how to diagnose them. Check out Scannerdanner on YouTube, he's a diagnostics teacher and has excellent videos that are very informative. He teaches at Rosedale tech in Pennsylvania.
OP, you should reconsider your statement that Duralast is not a bad brand. I don't like generalizing anything negative on any particular brand, but I have yet to buy anything Duralast that wasn't junk. I buy lots of other parts from Autozone, but no more Duralast.
That said, I do agree that killing multiple ICMs quickly is likely not a brand problem. If nothing else, consider getting good heat sink past, rather than using the crappy dielectric grease that comes with most ICMs. If the problem is excessive heat, that might at least buy you more time and give you other data to consider in your investigation.
