Please help. Any and all help would be greatly appreciated. I'll try to make the story as short as possible. Last week, when the weather started to get really cold, I decided to switch out the Buschur Racing mini battery and put in a full sized battery. There were a few reasons why I wanted to switch the batteries. First, I've had the mini battery in the car for the past 3 years. Within those past 3 years during the winter, the car would have a hard time starting up. I understand that the cca on the battery isn't what the car requires, but it would only not start a few times within those 3 years. Well this year, I was a little worried about it because I just became a father in August and wanted the car to fire up every time, so I switched out the mini battery for a die hard that I purchased 3 years ago.

After switching out the batteries, the car fired up every single time without a problem, but here's the problem. When I first switched it out last week and took my son to daycare, the car's idle would drop down to about 300-400 rpms whenever i was at a stop, with the clutch pushed in and the being in neutral. I look at the turbo timer and had it set to read the voltage and noticed that the voltage dropped from 14.0-14.1 to 11ish. As I started going again, I didn't have a problem, voltage back up to the 13.9-14.1 range...the car seems like it wants to die when i'm about to slow down to a stop. Never had an issue with the mini battery in the last 3 years of it doing that. So I decided to wait a few days to see if it would clear up because of the battery just sitting there for the past 3 years.

Nothing changed. So I changed the battery back to the mini and it seemed fine. then the other night, the car wouldn't start. Jumped it and it was fine. Then a day or 2 later, after work, the car wouldn't start. Tried jumping it for about a half hour and nothing. Meanwhile the die hard was being tested and tested ok, wouldn't retain a full charge, but would retain a charge over 12v, which companies feel that it's a good battery. I decided to leave it at the shop who tested it.

I get it flatbedded to a garage and had them look at it with the mini in it and they found that the mini was no longer any good. I went out and bought a yellow top optima, installed it and the car fired up every time I tried. As I was driving it home, each time I had to slow down to a stop, had the clutch pushed in and the car being in neutral, the same symptoms came up. I don't know what's going on.

I don't know if its a starter issue, alternator issue, bad connection or what. I tried running the car then disconnecting the negative cable from the terminal and the car was still running.

The evo was tuned on the stock ecu, has hks 272 cams, BR stage 3 head, 3" turbo back with no cat. AMS fmic, AMS licp, BR intake pipe, manual boost controller, walhbro fuel pump, and a few other things that I don't think would be a cause.

If you have any suggestions and/or answers to what could be the issue, it would be great! Thanks for reading guys

 

it might be as simple as adjust the biss (base idle set screw) .. sounds like the idle air control valve is out of calibration and is having a hard time catching itself, which is causing it to dip in the 300-400rpm which is enough to stall the engine.

 

Thank you, I'll have to look into that when it gets a little warmer out

 

I have not seen a how to adjust that thoroughly executed. it would be sweet.. I tried adjusting mine, but its still having idling woes. my evo scan actuator does not work with my ix rs. Im thinknig there is a MUT address wrong somewhere?>

 

dude simple problem your vehicle goes through a relearn stage each time the batterys disconnected...now if the problem persists after a few drive cycles then theres another issue... now even though the batterys good alternator or starter might be startin to freeze up...have it checked with a charging system checker that most shops carry, and if they check out ok, look into checking the wiring from each to see if theres something shorting out there...
good lucj

 

I'm having similar issues. I'm going to look in to the base idle set screw and the idle air control valve but it won't be for a couple weeks...away on bidness.