nigelt

iTrader: (10)

I'm not sure what section to put this in, because I don't know what the problem is yet.

Story time:
Track day today, and around the 4th lap under WOT I lose power for a second. It was just a blip, check engine lights comes on, and I limp back to the pits. Upon inspection, it seemed that the MS Labs CAN wideband module was hanging from my glove box. I assumed that the problem was that it lost connection for a second because it was hanging down. Car runs fine at that point.
Second session, around the 4th lap I lose power completely. No electronics, no brake pedal pressure or power steering. Won't restart right away so I coast to a safe place and get towed off the track.
After the car gets towed, I look under the hood and the coolant reservoir has overflowed and is boiling. Car cools off and I fire it up. It turns over and then dies. I do this a couple times and with a little gas I can get it to start. Big chunk of catalytic converter comes out of the exhaust. I don't know if it's related to the apparent overheating, but after a good cool down I drive home and the car seems to be running okay. I gut the cat, missing the third session, lower the boost to about 11psi and get back just in time for session 4.
Session 4 goes well, 3/4 throttle the whole 20 minute and no issues.
Session 5 I right before the end of the third lap I lose power again. Check engine light comes on, and I coast into the pits. After about 2 minutes I can start the car and limp back to my computer to plug in and see whats going on. The car is hot at about 101C, but no evidence of real overheating.
Day 2 tomorrow, so I want to try everything I can to resolve this issue.

Questions:
1. If I logged when the CEL was on, can I see from the logs what code was being thrown?
2. Any ideas what might be going on here?
3. I'm aware that I'm pushing my cooling system with just a Koyo 37mm radiator and no other cooling mods. Tonight I'm going to do a coolant flush and replace the thermostat and radiator cap. Do we think overheating could be the issue here? Will the MS3 cut power when it overheats? I was planning to vent the hood for better cooling and can do that tonight.

Thank you in advance for any help you can provide!

patsmx5

iTrader: (16)

If you suspect your ECU is causing your issues, you need to review datalogs of the behavior and see what it's doing. Whether it cuts power or whatnot depends how it's tuned, I'm sure it can be programmed to do that. On my MS3 I just have it reduce timing and add fuel, it doesn't just shut me down since loosing power could be very unsafe in an emergency situation or when unexpected.

poormxdad

Nigel,

Was the power loss instantaneous? I had an issue where my engine would just suddenly and completely die. It would be running, and an instant later it was not. If the car was moving when it died, it would not jump start by popping the clutch. If I waited a few minutes, it would start and seemed fine, but the interval between cut outs got shorter and shorter. Over the course of one weekend, the car became completely unreliable. Long story short, I ended up on a flatbed--the MSPNP Pro had a bad module.

Let me know if you want more details.

nigelt

iTrader: (10)

That sounds exactly like what's happening with my car. Totally dead. Doing 60 and popping the clutch in 4th won't start it. Then after some time it will fire back up. I'd love more details! How did you diagnose it?

thumpetto007

iTrader: (15)

How new is your fuel pump?

CAS?

Try just distilled water in the cooling system.

How new are your ignition coils?

Reverant

iTrader: (10)

It sounds like the usual crank/cam overheat failure mode.

poormxdad

PM sent. I hope it helps.

eddyc49

I had a similar situation that turned out to be a loose battery. During certain situations, the battery would shift just right and the positive terminal would momentarily contact the hold down. Car would die for about 10-20 seconds, then come back up.

​​​​​​Didn't figure it out until I went to put the charger in and saw how badly the battery had shifted.
​​​​​

secretsquirrel

I will second Reverant on this...had exactly the same senario.

skylinecalvin

iTrader: (2)

I had a nb that also experienced this, so I keep a spare cam angle sensor in my glove box. Any way to prevent the overheating or at least minimize it?

nigelt

iTrader: (10)

Hood vent seemed to have made a difference. I made it through a full session without issue. Fingers crossed I get through the rest of the day and I'll replace the cam angle sensor. Anything else I should do to mitigate the issue? Any difference between generic and Mazda sensors?

wackbards

iTrader: (2)

FYI, AutoZone offers a lifetime warranty on them. I just bought two. Keep one in the glove box, and bring in your dead ones for new ones at AutoZone every time one fries. IIRC, you don't even need a receipt.

Leafy

iTrader: (1)

I wouldn bother with those. At least for an auto-x car all the parts store ones last like 2 auto-x runs before they go on the fritz. Longer if you douse the sensor with water between runs. Best bet is to find a factory one without the Mitsubishi tri-star logo on it in the junk yard and use that. Or go hunting through the thread about the cam sensor issues to figure out what conclusions everyone came to (evo 8 sensor?).

skylinecalvin

iTrader: (2)

Just spent the last half hour reading through the thread I linked below. It looks like the evo 8 sensor will work if you DON'T have vvt. If you do have vvt, it won't detect the 2nd(?) tooth or something like that and the vvt will stay fully retarded. I'll keep looking around though. Somebody must have thought up of something to at least help alleviate the issue.

https://www.miataturbo.net/ecus-tuni...e-74009/page8/

nigelt

iTrader: (10)

After half sessions all day (cut short by this issue), I grabbed an AutoZone sensor and threw it in before my last session of the day. I got a full 19.5 minutes in at full clip and it was amazing. In the last lap I blew my head gasket.