Hello all. I'm back once again, as this board has always proven helpful in the past and I have no doubt y'all will provide results once again.

I have an intermentent problem that I think I am about to solve, but I am ignorant of too many things to know for sure.

Here's the detailed situation from beginning to now. If you want a TL;DR, skip to the bottom.

>car runs good
>one night while driving in the city, notice lights are dim
>amp gauge in dash show it is at 8 instead of the normal 14
>car seems like it wants to die - rough idle, decrease in power, some surging
>never dies, make it to destination
>drive home, NO problems what so ever

>few days later, drive again at night
>lights dim, amp gauge down to 8 again
>this time, engine runs so rough I cannot keep my speed and I pull over. Sputtering, I shut the car off
>wont start. Cranks, but doesn't turn over at all.
>15 minutes later I get it started somehow
>drive home, park

>next day replace alternator since it is suspect and has a squeaky bearing anyway
>attempt to start car
>cranks, will not run just like last time
>notice I cannot hear the fuel pump priming
>check fuel pressure at schraeder valve - nothing
>replace fuel pump relay - no change
>put 12v power directly to Pin G under dash, and notice fuel pump primes now!
>Stumped, I research some and then notice the CEL does not come on when key is in ON position
>find out about the ECM inline fuse
>Check fuse. It isn't blown, but the plastic around the metal fuse is bubbly and melted
>replace fuse, car STARTS AND RUNS!

>drive car during the day time for 30 miles, no issues
>drive car again that night, it does the same damn thing after about 5 minutes
>notice the CEL is, once again, not lighting up while in ON position
>check ECM fuse, fuse is good but notice that the housing is super hot
>further inspect the ECM fuse housing, notice the orange wire at the housing has a lot of corrosion
>in order to get the car home I cut off the fuse housing and wire it directly together
>5 minutes later CEL light is there
>starts, runs fine, get it home
>no more heat in that wire

>start it up this week (daytime), let it idle for 5 minutes, rev it up and down in park for 5 minutes, runs fine. No issue

TL;DR - Amperage was off, car ran weird, then died, verified it was not the fuel pump or FP relay. Finally discovered the ECM fuse was buggered because of a lot of heat/resistance at the fuse housing, cut it off and wired it directly, and it worked fine getting home. Test ran engine during day again, no problem. No CEL at all during any of this.

An obvious pattern here is that this has only happened at night, when my lights are on. I find this strange, though, as I replaced the alternator and it still continued. Does anyone think this is significant? If so, how?

Anyway, where I am at today is rewiring the end that I cut off with a new fuse and housing and then test driving it with and without my lights on. I will post the results here later, but until then, my main question:

The ECM. Does it have a standard procedure for "resetting" when the power it recieves from the battery is intermittent/ insufficient? It seems like it does, but the search on Google and here has not netted me any info on that. Is there a way for me to manually "reset" it? Is this entire scenario a symptom of the ECM going bad?

How does the EST module, alternator, and burn off relay play into this, if at all? I know some of these items are connected by wire to each other, and obviously all are connected to the ECM in different manners.

If anyone could shed some light on this issue, it'd be much appreciated. I've searched this forum and found a lot of people with ECM related issues, but nothing quite like mine, so I decided to make this thread.

Some additional info:

-ECM is original, but the PROM is one burned for me by Hawksthirdgen back in 2010.
-Engine is a ZZ4 Crate that was swapped back in 2010, hence the new PROM.
-Car was originally a 305 TPI. I kept the TPI intake and fuel systems on this new engine.
-Ignition coil and dizzy are MSD. Also have MSD box connected.
-MAF is only 4 years old, fuel pump is 6 years old, battery is 1 year old

Thanks in advance.

 

Resetting the ECM consists of disconnecting power to the ECM (however you want to do that IE battery, unplug it, etc...) This will not erase the prom you had burned. ECM will take a small amount of time to "learn" and "fill" the variable tables to run optimally after reset.

You should be able to succesfully check the computer for error codes

https://www.thirdgen.org/service-eng...ht-error-codes

 

I suspect you meant to write "8 volts" instead of amps. Operating at 8V will skew a lot of ECM inputs. Solve the undervoltage/charging system issue, and that may just cure your other ills.

 

Just for posterity's sake, I did replace that ECM fuse with a new, good holder and fuse and rewired it properly and it has solved my woes.

Thanks Keoman for the info, and thanks Vader for that, as you were right. The improper voltage was the direct cause of the cars inability to operate.