To add to this, diagnosing electrical issues on a car is much easier with a voltage meter than the trail and error approach. If you don't have one, 20 bucks will buy a good one.

Here's one on Amazon Prime, 9.98 shipped


If I have an electrical problem, I don't start messing with software and hardware until I've diagnosed what's going on. It's much easier/faster and less overwhelming this way.

Rather than a DVM (certainly valuable, but somewhat unwieldy while you're driving), I like to do something like this:

Mini 3-wire Volt Meter (0 - 99.9VDC) ID: 705 - $7.95 : Adafruit Industries, Unique & fun DIY electronics and kits

Stick it on the dashboard with double-sided tape and wire it to the reference point and you can glance at the battery voltage while you drive the car around. I actually have one in a standard 2 1/16-inch gauge pod, which was $25 when I bought it at Summit, but they don't seem to sell them any more.

--Ian

Good points. I'm definitely not opposed to having the correct tools. But in the same sense, I do enjoy some good discussion as to what problems it could be and where to start using those tools....if that makes sense.

Yes. I just want you to get it fixed without a lot of trouble. I would certainly not spend money on replacement parts before buying a multimeter when you have an electrical problem. But some people are afraid of electrical work and for them it's easier to change parts till it's fixed instead of diagnosing the problem first.



For reference, there's some guy on m.net that's had a miata (that's stock...) that won't crank for FIVE YEARS and he's made a thread asking for help. After I posted a few times trying to help, I told him to go buy the mazda manual and test every sensor as per the manual, and to post the results. Also told him to get an OBD reader that can show RT data and to use it to diagnose each sensors output in realtime. He hasn't done this. And I'm not helping him anymore, because if he hasn't figured it out on his own after 5 years, he either needs to drop it off at a mechanic or buy the right diagnostic tools to figure it out.

Take it easy and good luck! I agree with Ian btw, having a volt meter in the car would be sweet. I might buy one like the one he posted and stick it in the glove box just to have.

Wow. 5 years? Shit. I might be all over the board with what it could be, but I'll be testing those concepts a fuck of a lot faster than that lol. I did load Jeremy's latest map that had some of my settings plugged in and there were some promising results- AFR readings were much more stable and batt. voltage wasn't jumping around nearly as much. I didn't get a lot of time to play with it, but I'll try to more tomorrow (need to get some logs).

The thing that still concerns me is that everything was fine, but something went awry, indicating to me, that something has fallen out of spec/is changing values and probably needs to be replaced. Sure, I can change settings to compensate at the current moment, but if something is getting progressively worse, then something needs to be fixed/changed. With the new stuff, I have set target voltage to 13.5v instead of 14v. On my brief 30min drive home, I didn't see/feel any of the problems I had observed in the past week. Definitely a good thing. But I want to get to the bottom of this both for current issues and for future potential. Dunno if I'd put a volt meter in the car permanently, but I'll be getting my hands on a multimeter to go over various areas.

Could be brought on by the firmware change, honestly. If Jeremy said your old map needed to be changed, i wouldn't expect your PWM1 parameters to go unchanged, either.

I wouldn't necessarily point fingers at your actual charging system yet. Like i said on the other board, this is exactly what happened with mine, right up until i switched to Haltech, then never had the problem again. I didn't change battery or alternator.

These issues started a week before anything with the ECU was touched/changed. AFRs have smoothed out, but voltage is still dithering all around....just at a lower range now that I dropped alt. output to 13.5v.

The radio hasn't cut out since updating and dropping the target voltage.

Nevermind- I'm seeing the original issues again. Radio cut out on me, AFRs are dithering again and some other things I'll log in a bit when it cools down/traffic dies down.

So after driving a couple weeks with the target voltage set to 13.5v, all was mostly well- no radio cutting out or stumbling.

So Friday, I set target voltage to 14v for fun and immediately the radio cut out and I got the engine/ignition stutter when driving. Set it back to 13.5v and still had issues. Finally swapped my alternator this morning and went for a drive. The stutter issue subsided after about 10min of driving and on a few occasions the radio cut out...but not quite under the same conditions as before- this time it was only when decel'ing in gear for several seconds, not the throttle tip-in that I had previously.

The big issue I still have is idle droop when turning the lights on, or turning the blower to full and a bit when the fans kick on. If any one of those systems is on and another one is added , droop is quite noticeable. Watching voltage output on the Hydra really doesn't show anything when just one system is turned on, and a dip to ~12v when one is on and another load is added. Also noticed cranking a.couple times today has been slow/low. So next is a battery......I'm wondering if the bad alt. has had an impact on the battery....


Opinions?

I would start swapping parts until the problem goes away (battery, alternator, ecu controlling alternator, change ecu settings, etc) and definitely don't buy a 10 dollar volt meter and test anything first. :noob:

:middle finger:

lol

Considering 190k on the alt. and a battery that's 7+ years old....replacing them isn't a bad thing either way.

I really can say though, that with a multi-meter, I wouldn't know where to start taking measurements and how to analyze such data. Its sad but true...I'm more mechanical-minded :/

You hand alternator to autozone employee. You say "test this". They say "ok". It says "pass" or "fail". If pass, reinstall. If fail, buy new. Same with battery.

It's that. fucking. simple.

Edit: I should add, after buying a new alternator from them or used oem online (recommended), have them test it before installing.

Post 12 would be where to start with a multi meter.

That said, if you'd rather swap parts then deal with electrical diagnosis, I wish you luck. That can be a time consuming pain the in the butt too though.

Well, with the new alt. and battery, and target voltage set to 14v, the stuttering and radio issues are gone.

Sorry for my stubbornness/forgetfulness, there is other shit going on that's affecting me lately...and it's not fun.

First off, I will be swinging by somewhere and grabbing a multimeter...and going through what's outlined on page 1.

Anyway. Driveability of the car is better. However, I went out to get some logs tonight and still have an issue somewhere in the car. Doing a solid WOT pull, the CEL illuminates just north of 6k and turns off as soon as revs drop. No other lights, no other noticeable symptoms. Looking at the logs, voltage isn't doing anything funny at that point either. Sent a previous log to Jeremy and he noticed RPM data showing a symptom of too high of voltage in the circuit by way of an oscillatory motion just after a drop/change. I saw this again in my logs from tonight. Per his advice, I'm going to drop target voltage down .1v and taking more data until it stops.

Anyway, now its the CEL coming on after 6k that I need to figure out. Here is a quick screen shot of the log I just made...starting in 2nd and running through 5th hard...then light cruising for a short time.

Doesn't the check engine light work with knock?

It does/will, but when the Hydra sees that and throws the CEL on, it'll stay on until the power is turned off. Its not doing that though, it goes off when RPMs drop back down.


* The CEL coming on at 6k+ RPMs is load dependent. I just found this out because I changed the target voltage down to 13.7v and went to do a pull, but the roads are too wet for traction at WOT under 4th gear. In 2nd and 3rd, I got wheelspin up to redline, but my load was not high, and the CEL did not come on. I also rode out 2nd and 3rd at part-throttle to redline and the CEL did not come on. In 4th at WOT, the CEL came on at higher RPMs. When it first happened, I checked the tension of the alt. belt and it seemed a bit on the loose side. I tightened it up to "yeah, that's definitely tight enough" but the aforementioned issue still happened. Hmmmm....

<p>CEL is controlled by the Hydra, so you need to look at the tune and see what is turning it on.</p>

True. I know from past experience of a friends car, it did that because the alt. belt was slipping and voltage was dropping at high RPMs. Dunno if it was an internally or externally regulated system.

My understanding of the Hydra using the CEL for knock is that it will flash and go into a backup map. I've experienced this a couple of times in the past, but not since putting the new engine in over a year ago. However, I am seeing some info on the web about conditions and settings...and its making me wonder if the map I got from Jeremy has a slightly lower threshold for background noise. When I get home from work, I'll compare the threshold from my map to Jeremy's- if its different, I'll set it to the values I had been using and see what happens.

<p>Weird electrical issues could potentially cause noise on the knock sensor and false knock.</p>