Genom

I post this here in case it's happened to anybody else.

I was out practicing some slalom work with Alex and lourx8 this saturday. While driving my car around I noticed at some point there was a strong burning electronics smell. At the time I assumed it was just rubber, sicne the AC was running on a warm day, but now yesterday afternoon afterwards and this morning I have noticed that the car has almost no power below 4000RPM, and then the usual power above it. I disabled the stage1 and it's exactly the same. I'll pull the stage1 out tomorrow morning as I need to drive a bit still and the hardware for mounting the ECU properly is about 50 miles from me.

Has anybody else had this happen? Just to clarify there is no CEL lights, no warnings or anything like that. It's not like the switch on the stage1 was bad or such. Car just has no power down low. As an example at 40MPH in 6th gear, flooring it takes about 30 seconds to get to 50MPH.

Winning_BlueRX8

posted by emailists:

similar? maybe

dwebb

I got my "M" flash last Friday (or so I believe; the dealer claimed to have updated the ECU).

Since then I've smelled the same burning rubber smell when I drive it.

Power is good. No performance problems. Just the weird smell making me a little nervous.

Dan

Genom

emailists problem sounds a lot like my own. The odd thing is I have been running this setup for at least a month with no problems.

I am going to check the map loaded in the stage1 now and if that looks OK I am removing it so I can take the car in for service.

Genom

As an update, I checked the stage1 and the map showed up correctly. Checked the wire harness and didnt see anything burnt on it or in the case. Since removing it the car still feels a little week, but it seems to be getting better. Only got to drive 20 minutes or so though so later tonight I'll take it for an extended spin.

Genom

With Mazdamaniacs help I have seen that indeed I have at least 1 burnt coil, possibly 2. I'll let Maurice know.

TitaniumRX8MD

Genom what do you mean burnt coil? Cause I think I have the same setup as you but never experienced a burnt smell and no loss of power. Please elaborate, thanks

Genom

If you look under the corrugated tube that goes from the airbox to the throttle body you can see 4 units lined up. These are the ignition coils and are in charge of sending the signal to the spark plugs if I understand correctly. Look at the pic Maniac posted in the toehr thread and you'll recognize them. If you look at them from the driver side of the car you can see the top of the connector that Maniac describes and seeing the 4 side by side, it's pretty obvious to spot the ones that have melted. If you havent lost power, then your fine. Rememebr that this is not a new stage1 install. this was a setup that ran for over a month with alot of driving. it wasnt until I bused the car on a hot day that I had a problem. Bfre that it's been great.

smrx8

iTrader: (1)

GENOM no matter how you drove the car the stage 1 is not suppose to burn your coils its a performance mod. how else are you suppose to drive it .it may be the stage 1 was not working right .i heard other people had problems too but maurice fixed it.let us know how you make out.

Racer X-8

This doesn't sound stage 1 related at all.

Genom

Why not? It's controlling the coils, and before the adapter board was figured out it would burn coils up. Maybe there's something that needs to look at as a long term thing.

guy321

it probably is related to the tuning, i remember CZ and mazdamaniac both burning out coils when they were tuning.. You're right, it IS a performance mod which means that you are potentially running a slight bit more "dangerously" than stock.

Performance typically comes at a loss to reliability. This does not mean that the CZ unit is bad, it's just that the map might be a little too agressive in "our" (central/south florida) enviornment. I for one don't mind having to change out 2 $60 parts once in a while if it makes my car run a little better. As long as it doesn't happen every week.

rx8miami

yikes, burnt coiks w/ stage 1. a question for you guys I am seriously considering buying stage 2 but that might even pose a greater danger than stage 1 to the above referenced. why is it that you rarely hear about anyone buying stage 2 when it is so much of a better deal for the $? Is it the fear many have of burning the clutch or what?

TitaniumRX8MD

Just for clarification I looked at my coils today and I couldn't see anything. Do you actually have to pull it apart to see if there is any damage or would be able to see it right away. And if you do have to take it apart, is it easy to do and any instructions?

Omicron

Could be you just have defective coil packs. But it could also be the CZ unit.

The Stage 1 is basically a Greddy eManage that has a custom CanZoomer Stage 1 map for the RX-8. I believe the problem is that the eManage does not let the voltage to the coil packs drop to zero Volts in between charge/discharge cycles as they expect and need, so they heat up. 99% of the time they can handle this and not overheat, but you may be in the 1% that cannot.

Last I heard, Maurice is working on a fix.

Genom

Maurice will take a look at my unit and see if maybe the putput is to high or otherwise borked. I'm not too worried about it though. If it was slightly bad coil packs, the poroblem has been fixed, and if it's a recurring thing, then it will be time to work out something else. But I aint gonna worry about it until it is.

guy321

Thanks, please keep us abreast of the situation as you get more information. I'm in the same boat as you, although I have not experienced that problem. I have noticed some preformance degredation as I take long drives in the heat.. I have not yet blown my coil packs.

r0tor

iTrader: (1)

i took a long trip today and smelled something funky like electronics burning and I don't have the CZ mod... i didn't notice any performance loss though and i thought maybe it was just highway traffic fumes. I guess i will see what happens in the future.

RX-8 friend

I've been watching this and keeping quiet as I have no definitive facts to put forward yet, however, I have a theory as to what is happening. I will be doing more measurements soon (waiting for a scopemeter to arrive).

The coil packs consist of a smallish coil and a power transistor. The power transistor grounds the coil primary. The other side of the primary is connected to a resistor and then to +12V, both in the wiring of the car. The PCM sends out a +5V 5mS pulse to the base of the power transistor to turn it on. The power transistor draws enough current in the base to load that down to +3V.

I think there are two potential problems with this setup (no pun intended . Unlike most current logic chips, the voltage that the PCM puts out goes from 0V to +5V. Most logic puts out +1.4V or so when "OFF" to +4.4V or so when "ON". This is what our box puts out, so we had to add a series diode to the ignition output of our unit, as 1.4V will keep the transistor somewhat on and heat it up. That is what happened to Maurice's coil packs and Maniacs as well. The diode drops the voltage by 1V or so. The transistor doesn't start to conduct until the base voltage reaches 0.7V or so. Problem one solved.
Problem two is transistors loose "current gain" when they get hot. The PCM only puts out so much current (hence the +5V drops to +3). If you don't drive the coil transistor to full saturation (minimum voltage drop across it) it will dissipate more than normal saturated power. Think of it this way (for those without electronic experience). The +12V flows through the resistor (causing a voltage drop across it and limiting the ultimate current through the coil), through the coil (causing a voltage drop across it and charging up its' magnetic field - inductance), and through the power transistor (which will have a small voltage drop across it when saturated). Each component will dissipate heat based on the voltage drop times the current. This heating will cause loss of current gain taking the transistor out of saturation if it is too much. This will generate more heat which will further drop the current gain in the transistor which will further increase the voltage drop across the transistor. It's a classic thermal runaway situation.
So, if you operate the car in such a manner that heat builds up in the engine compartment you will get closer to triggering this scenario.

I will be doing measurements to confirm this, and if this is the correct analysis, we have a cure and will let you know. Our box actually puts out more current than the stock PCM, so this should be solvable with it. More current will keep the power transistor in saturation at higher temps.

Just to finish the ignition phase, when the 5V 5mS pulse ends the power transistor turns off and the coil field collapses, causing the ignition spark.

Oh, and I doubt you will smell this happening. First, it's in the engine compartment and you don't get smells from there too easily (or you would be gassed by all the smells the engine generates). Second, all that happens to the coil pack is the heat causes the casting compound to swell. It doesn't actually burn.

snap-on

I wonder if we can have a company like MSD build some remote coils.
They would no doubt be stronger and if they are mounted somewhere(anywhere) off the engine, surely the heat would be reduced.

Omicron

Now that's a thought! Anyone have any contacts with companies like MSD?

Xyntax

I have had this similar situation happen once. I wasn't even driving it hard. I took a left turn when the light turned green and after shifting to 3rd, I smell an awful burning smell. I immediately pulled over with my emergency lights on. I inspected the engine bay but I could not smell it anymore. I have thought it was the car I was following. I should check my coils tomorrow then.

Also, ever since that, I have not noticed any problems with how my car is running. I dunno, maybe I'm just not noticing "it" yet. Yikes.

Genom

rx8friend: Lets just say I can smell a burning IC a long way off :D

I'll be shipping my stage1 back to Maurice tomorrow for him to check it out.

shebam

Er, is this more likely from sitting in traffic or driving like you stole it? Or cruising at 75 mph? Serious question.

olddragger

iTrader: (3)

same question as shebam. also just a thought. I wonder if the engine cover is restricting any air flow?
I also wrote on another thread about heat concerns (i live in georgia) and the cz unit. I have the 1.1 and have been running it about 2 wks. No problems and it has been around 93 degrees, but I am a conservative driver and I haven't taken any long trips. I also wonder about the heat and the unit itself. Its pretty tight in the ecu box.
errrr maybel , I need to stop wondering and just drive my car LOL!
Im sure cz will address these issues but lets keep this thread going.