Hey guys. Been a while since I've been on here and my last post was on buying an RX-8. Well, I ended up buying one in 2019 and it hasn't given me any issues, until now.
I find that while I'm driving, at above 3500 RPM - my engine seems to cut off for a split second and then come back on when I open up the throttle. What is very weird about it is that it is completely random. Sometimes it happens, and sometimes it does not. I've already tested compression (it was in the mid 70s), checked the MAF, cleaned ESS, checked fuel pump but I have absolutely 0 leads on what the hell is causing the issue. Everything appears to be operating properly during the event, no check engine code is thrown or misfires either.
Had the car checked out at my regular mechanic in Indiana and he didn't find anything wrong with it - even went to a specialist in Dallas, Texas (Rotary Performance, if anyone is interested) since I drove the car there a couple of times since I had it; and even they were bamboozled since it was a random occurrence.
I was wondering if anyone here would have an idea of what may be happening and help me narrow it down.

If you're having trouble imagining what this may be like - imagine looking at the rev-counter at 4000 - sudden cutout - then 3500 again (I usually let off the throttle when this happens).
So, guys - any ideas?

 

Is the engine on factory flash?

 

Hm, no - have a tune on there for slightly increased oil injection to emulate the R3 model. Think that may be causing the cut-offs?

 

If you are using older version of VT then it might be the cause

 

Hm, you might be right. Let me check to see if there were any new versions before all that.
Hey, you don't happen to own a black RX-7, do you?

 

VT has released new version that fixed the problem, if you updated and the problem persists, email them.
Unfortunately I don’t but I would very much like one though😂

 

I see, let me check if that was fixed and I'll report back soon after. I thought I might know you when you mentioned VT, so that was a challenge question lol. My apologies if that was weird.

 

Do the electronics cut out too? Gauge cluster, radio, etc? It sounds like a loose electrical. Battery terminals, ECU plugs, etc.

 

Hey Loki,

Thanks for responding. During the cut-out there isn't any loss of power to electrical systems. Gauges function normally, and only the RPM counter goes down on account of the cut-out. The engine light comes on for a millisec and then goes away just as though the car was being turned on. No cranking or anything, it just straight up dies and comes back to life almost immediately.

 

But, when you say it goes down, does it go down to 0 or to slowly wind down as the engine slows? Because the gauge cluster is digital, if its dropping out the problem is electrical. If an electrical connection is lost, or the ECU loses power, the rpm signal will drop to 0. If only the rpm signal is dropping to 0 but speedo still show speed, I would examine/clean/replace the eccentric shaft position sensor. Reset NVRAM while youre at it, may help. If speedo and tach drop to 0, your ECU is losing power and you may want to look into its connectors.

If rpm slowly winds down with the engine, then the sensors are all OK but for some reason its unable to fire. I have a hunch from the description that its the first. Almost anything else would throw a check engine code of some sort.

 

So the cluster displays speed when in motion, yes. But the RPM gauge goes all the way down to 0 for that one millisec and the winds back up to what it was before the cut-out. I should add that the cut-out is also accompanied by deceleration that sometimes makes me think I accidentally pressed the brake pedal when I in fact did not. Guess I'll add an inspection of the stupid ESS to my checklist again. Both that and the MAF have been an issue for a while, either due to debris settling into the ESS or it being fouled by dirt. I can't count the times I've had to diagnose them time and time again.

 

Maybe its the wiring to the ESS then. And definitely do the NVRAM reset. But it pretty much has to be something about the ESS based on the symptoms.

 

All right then Loki, keeping your advice in mind - I'm going to have a look at the ESS once the weather clears. I think I'll update my version of VT while I'm at it, though I don't see any fixes listed in the patch notes that point to a random stall during operation.

 

https://www.rx8club.com/rx-8-racing-...-track-269957/

 

Zhang, that's a lot more like what I described. Thanks for linking!