I'm not entirely sure these issues are related, but after switching my ls vtec on s300v3 to COP (burton racing kit with new Denso coils) I'm having issues with the charging voltage being all over the place. The car will start but doesn't stay running on its own, and when I use the gas to keep it running it's anywhere from 12-20 volts per the datalog. You can watch all the interior lights repeatedly get super bright and then dim again as the voltage surges. Don't worry, the car had plenty of oil pressure (oil/coolant/fuel pressure & ethanol sensor aren't calibrated yet)



I initially assumed the issue was the voltage regulator in the alternator so I replaced the alternator, but unfortunately, that didn't change anything. There wasn't anything in the COP kit instructions regarding settings in Hondata that needed to be changed, and it looks like the COP settings in SMangaer are just for Hondata's own COP kit, not this kit from Burton Racing. I just emailed Burton Racing to confirm no settings need to be changed in SManager.

With the new alternator, the car did run fine at first for maybe 2 or 3 minutes before the voltage went back to going all over the place. The ELD is disabled in SManager and for reference I'm using a small AGM battery, pc680 size mounted behind the front bumper that's 4 months old. The car has been sitting not on a charger for maybe 2 weeks and the resting voltage on the battery is 13 volts which seems high to me, although from what I see it's not abnormal for AGM batteries to rest higher than the 12.6 volts we're used to with lead acid batteries. The ICM and OEM coil are removed from the distributor with a block-off plate. Any suggestions would be much appreciated

 

I'd be suspicious of the voltage regulator in your new alternator. I've had one bad right out of the box. I've experienced the super high voltage thing too with interior lights getting super bright and windshield wipers speeding way up. It's weird as hell.

 

Where did you source your replacement alternator ? I suggest a Genuine Honda Reman... pricey, but it will work longer than a day.

 

Did you check the ALTc function or whatever that hondata instructed. I know its for hondatas kit, but it may make a difference.

 

That's not a bad point, I didn't really consider this new one could be a dud as well. Just started a return and ordered another one that should be here this weekend

The replacement alternator and second one I just ordered is an ACDelco from Rockauto

I tried it with that and the other two COP settings unselected and selected but it didn't make a difference. Apparently I'm also blind as I ended up finding the instructions and they do actually say to leave those three things unchecked (last bullet), and it's even highlighted



In other news, Burton racing was quick to respond to my email and stated "This kit is on a completely isolated circuit within the ecu itself and is unable to effect the ecu directly as it does not change or modify any signal or input the ecu reads/receives. There is something else going on or the kit was installed incorrectly." They then asked for pictures of the install including soldering and I sent all of that, and they responded by asking to clarify that I'm using resistor type spark plugs (I am) and suggesting that I send the ecu to them for diagnostics since they didn't perform the COP board install. I guess I can keep that option in mind if the second replacement alternator doesn't end up fixing anything.

 

Sounds like they have good support, that's nice.

 

Update?

 

So did the car only work good the first time you started it for 2-3 minutes. Or if you turn the car off, let it cool off, then cold start it again will it operate good for 2-3 minutes?
Or do you mean it ONLY worked for two-three minutes once and that was all?
What about if you enable ELD- does it make a difference?

 

Just put the second replacement alternator on and it seems to have fixed the problem thank you Dax! I can't drive the car right now but it sat there idling for 10+ minutes and warmed up the whole way perfectly fine

I initially test-started the car with the COP kit and it started up ok, but the idle was definitely abnormal (almost loping like it had a huge cam). When I went for a drive it immediately started sputtering and barely wanted to run once I pulled out of the driveway. My brother made some changes in the tune trying to get it to stay running at idle which looking back on it may have just coincidentally fixed the issue - I believe he left the ELD disabled the whole time. Then we drove a few minutes down the road to a friend's house and were getting ready to head out to a meet. Once I started the car back up (it only sat maybe 5-10 minutes) it was running all weird again as in a surging idle, wouldn't stay running on its own, and this time I noticed the dash lights getting super bright and then dim repeatedly.

This was when we decided to datalog and noticed the voltage jumping all over the place, so I assumed the voltage regulator in the alternator was toast. Ended up trailering the car back to my house since I wanted to get a little higher output alternator if I was going to be replacing it anyways (the parts stores around me had standard reman alternators but the ACDelco one is rated at 110 amps vs the standard 90 amps). When I got the first ACDelco alternator I put that on, and the car started and idled fine for 2-3 minutes before it started doing the same exact thing with the voltage surging all over the place. The part number is the same but the second ACDelco alternator came in a different box (on the right below), so not really sure if there's actually a difference or not. As long as it continues to work I guess that's all that matters

 

Glad it was a simple fix!