Replace distributor module again - no spark

[bryandavis]

Months ago, troubleshooting a poor running problem (while truck was running poorly for weeks), I replaced plugs, cap, wires, coil, distributor pickup, fuel filter, throttle body and finally, to fix the problem the fuel pump. After a couple weeks of running, one day... the truck would not start. Later the same day, it started & ran fine for a few days. Then the problem resurfaced. I found the cause was no spark from the coil. Having recently replaced all other parts, I replaced the ECM in the distributor (with GP Sorensen part from Advance). Problem solved.

Since that time I have replaced the same part... for the same symptom 5 times. One time with a Bourg Warner (Auto Zone) part all others Sorensen (Advance). I am getting about 3 weeks out of the part before it dies. I took one back to test at store & test reported good, however I never returned the part to service. Replacing it with a new ECM immediately fixed the "no spark" issue.

Anyone have any thoughts on the matter? Why would the part need replacing repeatedly. Could the pickup I replaced be causing the issue? Thanks in advance for any advice/opinions.

[GMMerlin]

You are not replacing the ECM , you are replacing the IGNITION MODULE.
next, what year make,model and engine do you have?

I stay away from most aftermarket ignition componants and only use factory parts...you might save a couple bucks, but look at the time and effort you have wasted

[bryandavis]

Engine is V8, 5.7L, EFI. Per your comments, GMMerlin, you tend to believe the problem here is poor quality components? Is it reasonable to assume the initial failure of the factory unit is not related to current failures?

[GMMerlin]

Originally Posted by bryandavis

Engine is V8, 5.7L, EFI. Per your comments, GMMerlin, you tend to believe the problem here is poor quality components? Is it reasonable to assume the initial failure of the factory unit is not related to current failures?

When you replaced the module, how did the pick-up coil look? Was it yellow and appeared to be falling apart?
if so,this may be the real failure.

As far as aftermarket ignition parts go...I am not a fan..have had too many problems with non OEM ignition parts and will not install them in my customers vehicles.
Since I stopped using non OEM parts, my return rate for failures has dropped to almost nil.
These parts include..modules,coils,sensors,plugs,plug wires,distibutor caps and rotors.....just my

[Fireplug]

Did the put the heatsink cream under the module if not he could be kill the new mods

[DDotson]

I hope you aren't paying for this part over and over again. The ICM is warranted for lifetime, at least the one I replaced is, ask your retailer and as was stated go to your GM dealer. I too have not had luck with after market parts. As for the testing of the unit the parts store test doesn't get the module hot enough to cause it to act up. Don't forget to put the cream (should be provided with the module) on the bottom of the unit when mounting.

[bryandavis]

Update! Problem still exists. Symtoms: on attempt to start, no spark is present. If I unplug both leads from the module, wait two seconds and replug them, spark is back & truck runs. Once I unplugged and replugged 3x with no spark resulting, I replaced the module with one of those previously removed, got spark. I have been running with that module for about a month and have to unplug/replug leads appx 4x in the last week.
The truck has cut off at speed above idle, while approaching a red light once; wouldn't start, uplug/replug fixed problem. Occasionally at idle, truck runs rough, like its going to cut off. I cannot detect any such problems at higher RPMs.
Other observations: I did not do the work on replacing the pickup coil, it was done at a shop, I do not know the part's condition. I have not purchsed any new parts since last post; thus still using "cheap" parts. As time passes... time between failure seems to decrease. Leads & terminals are clean. Themal paste has been used on all replacements. The last three mornings, at 1st start of the day, unplug/replug has been required; previous 2 days, throughout day no "hot" starts required procedure. This morning I uplugged/replugged leads separately. 1st the 2-lead harness; truck did not start. 2nd the 4-lead harness; truck started.
Any ideas? BTW, thank u all for your input to date!

[bryandavis]

To finish this thread... I hope... I have replaced the distributor pickup (this time I did the work myself). The pickup I removed was yellowed, but was not falling apart. The truck has started without fail for about 6 weeks now.

[Derby Driver]

well, I had a similar problem, changed all the components, (had a bad coil) among other things,
but heres one that stumped even a gm technican for the longest time , he gave me the "hint" as to what was wrong, IF you get spark at the coil you MUST get spark at the distributer (which I wasnt)
turns out, those "small distributers) the ROTOR is very tight, and the contact (the spring loaded one)
"breaks" the circuit "if" its not pushed down ALL THE WAY< because it is a tight fit, it feels like it is down all the way, but with just a little bit more pressure, it goes down about an 1/8" MORE! ta-da!
got spark now!!! so just wondering, if maybe a poor quality rotor was a not-so tight fit it could possibly "ride up" and break contact?? hope this helps some if not all ..........