Channing ECM fixed sluggishness…thoughts?
Thread Starter
Drifting
Joined: Mar 2017
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From: Nashville TN
2017 C4 of Year Finalist
Channing ECM fixed sluggishness…thoughts?
the following is from another thread of mine but I think it differs from the original topic enough to warrant a separate thread. I started off thinking I had a sensor issue but it seems the ECM was the problem. Thoughts?
Ok so weirdest thing. I got really into my car this weekend and replaced lots of fluids and the O2 and MAF sensors. That’s pretty much every engine sensor replaced now. None of that made much difference to how the car runs.
On a whim I replaced the ECM with another I had from my donor car. There was an immediate difference in performance. The car idles much better, power is instant, and the car feels like it’s woken up.
the only thing i can think, is that when i first got my car I swapped injectors with my donor as part of fixing it up. The donor injectors were not stock and may actually be 30lb injectors. That’s outside the tolerance of the stock computer to compensate for. The donor ECM most likely was tuned for the injectors (i have receipts saying it was purchased at the same time as injectors, but not why). I don’t know how to tell if that’s the case, but swapping ECM has made one of the biggest differences of anything I’ve done to the car. It added a very noticeable amount of power and I’m thrilled.
On a whim I replaced the ECM with another I had from my donor car. There was an immediate difference in performance. The car idles much better, power is instant, and the car feels like it’s woken up.
the only thing i can think, is that when i first got my car I swapped injectors with my donor as part of fixing it up. The donor injectors were not stock and may actually be 30lb injectors. That’s outside the tolerance of the stock computer to compensate for. The donor ECM most likely was tuned for the injectors (i have receipts saying it was purchased at the same time as injectors, but not why). I don’t know how to tell if that’s the case, but swapping ECM has made one of the biggest differences of anything I’ve done to the car. It added a very noticeable amount of power and I’m thrilled.
Thread Starter
Drifting
Joined: Mar 2017
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From: Nashville TN
2017 C4 of Year Finalist
Team Owner
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Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
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From: Nashville TN
2017 C4 of Year Finalist
The only other thing I’d be worried about is if the ECM has other tuning that might over-advance timing or something, etc. although it’s running so well now I think it’s fine.
Last edited by Bfenty; Oct 3, 2021 at 06:56 PM.
Le Mans Master
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From: New Jersey
Last new ECM I ever put in an 80s GM ran way worse than the one I suspected was flaking out... just saying it may be a little like Russian roulette. I don't know how later cars are compared to an 84 (mine is simple enough to get out) but if it is running just fine... I'd personally leave well enough alone unless you suspect something is amiss.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
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From: Nashville TN
2017 C4 of Year Finalist
Last new ECM I ever put in an 80s GM ran way worse than the one I suspected was flaking out... just saying it may be a little like Russian roulette. I don't know how later cars are compared to an 84 (mine is simple enough to get out) but if it is running just fine... I'd personally leave well enough alone unless you suspect something is amiss.
Le Mans Master
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From: New Jersey
I can see ECMs slowly failing... All the electrical components will inevitably drift per say... I see it with crossovers in speakers... nothing lasts forever and I am sure at that point in time a reman unit was simply anything visibly wrong was fixed and then it was tossed in a box and shipped out. I doubt there was any real testing done considering it had no prom. The company I interned for had systems that used similar chipsets and boards on a simple scale and the company that built them had a test rig. A lot of the ones that were bad tested fine on their machine but it wasn't calibrated like their specific system was and thus wouldn't work when brought back. I'd guess at that time their procedures were probably similar. Or I just got a bad one by chance lol.
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Thread Starter
Drifting
Joined: Mar 2017
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From: Nashville TN
2017 C4 of Year Finalist
I don't disagree with you. It was one of those "reman" units through an auto parts store with a warranty. You had to swap in your prom but it was the correct serial for the car. It just ran like dog poo with that one. I brought it back and they refunded me the 130$ and sent it back wherever. Mind you this was almost 15 years ago now and one of the first things I ever wrenched on with dad but I very clearly remember it just sounding bad and it stalling several times. It was a genuine GM ECM.
I can see ECMs slowly failing... All the electrical components will inevitably drift per say... I see it with crossovers in speakers... nothing lasts forever and I am sure at that point in time a reman unit was simply anything visibly wrong was fixed and then it was tossed in a box and shipped out. I doubt there was any real testing done considering it had no prom. The company I interned for had systems that used similar chipsets and boards on a simple scale and the company that built them had a test rig. A lot of the ones that were bad tested fine on their machine but it wasn't calibrated like their specific system was and thus wouldn't work when brought back. I'd guess at that time their procedures were probably similar. Or I just got a bad one by chance lol.
I can see ECMs slowly failing... All the electrical components will inevitably drift per say... I see it with crossovers in speakers... nothing lasts forever and I am sure at that point in time a reman unit was simply anything visibly wrong was fixed and then it was tossed in a box and shipped out. I doubt there was any real testing done considering it had no prom. The company I interned for had systems that used similar chipsets and boards on a simple scale and the company that built them had a test rig. A lot of the ones that were bad tested fine on their machine but it wasn't calibrated like their specific system was and thus wouldn't work when brought back. I'd guess at that time their procedures were probably similar. Or I just got a bad one by chance lol.
The unit I swapped in is a remanufactured one. So that could have something to do with it maybe?
Le Mans Master
Joined: Aug 2017
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From: New Jersey
I'm pretty sure that the prom is the vehicle specific tuning... IE the parts that can be adjusted in tuning... I'm not that familiar with those aspects however... Any tuning I've done I swapped to an EBL flash so its kind of a foreign language to me but I would assume that is a chip burn type thing that everyone has referred to. I to am unfamiliar but I do recall a ton of surface mount components in it that could go out of spec lol.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
I'm pretty sure that the prom is the vehicle specific tuning... IE the parts that can be adjusted in tuning... I'm not that familiar with those aspects however... Any tuning I've done I swapped to an EBL flash so its kind of a foreign language to me but I would assume that is a chip burn type thing that everyone has referred to. I to am unfamiliar but I do recall a ton of surface mount components in it that could go out of spec lol.