RIWWP

iTrader: (2)

I wonder if it's your front O2 sensor.


Just thinking out loud, something got fouled that shouldn't have, and it's interrupting spark and/or fuel when it shouldn't be. The plugs and O2 sensor are really the only things within the possible path of the seafoam and carbon.

I could be totally off base...

rickeo

iTrader: (1)

I had thought about that and when trying to drive when it would go into "tractor" mode, i was flipping back and forth between the AFR, STFT and LTFT and it would maintain ~0 for ST and LTFT and ~14.7AFR.

Then again, I'm in no way shape or form qualified for interpreting engine statistics.

9krpmrx8

iTrader: (46)

Hmmm. Well dealers can definitely fail at properly diagnosing the problem. Most of the time the techs are not even really professional mechanics, they generally just hire whoever and throw some training at them here and there. But going back to as stock as possible with known working parts is a smart idea.

So it's fine at idle but when you drive it screws up? I would lean towards a bad O2 as well. I probably have a working used primary O2 if you need it to try.

rickeo

iTrader: (1)

No it would do it at idle as well from time to time.

RIWWP

iTrader: (2)

Yeah, I wonder if it's reporting steady AFRs, when it actually wasn't.

9krpmrx8

iTrader: (46)

Hmmm, well at idle the O2 is not in play so that pretty much rules that out.

RIWWP

iTrader: (2)

Even closed loop idle?

When I was doing my decarb test, when it was idling and i introduced a fluid, the fuel trims would swing to compensate, swinging drastically to peg +25% or -25% if it was only on one rotor.

9krpmrx8

iTrader: (46)

At idle, it should be working from just the idle map and not taking input from the O2. It takes input from other sensors and the ECU will try to keep the AFR's at Stoich.

RIWWP

iTrader: (2)

Do vacuum leaks push it off the idle map? Since we know those trigger fuel trim changes at idle.

9krpmrx8

iTrader: (46)

I'm not sure what would cause the ECU to switch, but it is probably a number of things the ECU looks for when determining the switch. I know it's not strictly RPM related.

RIWWP

iTrader: (2)

Looking at the factory documentation, there are 4 different fuel system status modes:
Meaning of fuel system loop status
I'm fairly certain I remember the system status remaining in 'HO2S used for feedback' at idle. I don't think the AP can display fuel system status. Got an alternate OBD2 method on hand to test?

I'm 99% confident that the RX-8 runs on closed loop at idle once the coolant exceeds the warm up threshhold, even if it's using an idle map in that closed loop operation.

9krpmrx8

iTrader: (46)

Yeah, it would help to know what mode it is running in.

rickeo

iTrader: (1)

Well, its with the dealer now and I don't have a more comprehensive OBDII device. When I speak to them today I'm going to suggest a possible faulty front O2 sensor.

nycgps

iTrader: (1)

Mode 6 on the IDS would tell them what they need to know.

they can also monitor all output on the car for any malfunction

but do they know how to use those numbers and function is a whole diff issue

Karack

if it starts like a tractor when completely cold i wouldn't point the finger at the O2, even though it could be failed from the shock of the seafoam and create problems when running warm. but as of now the conditions do not meet those for a failed O2 sensor as the main problem.

tell them to do a full reset of the ECU, though i'm still guessing it is ignition related.

another possibility, one you don't want to hear is faulty coolant seals. coolant will foul the chamber and prevent it from firing, but this would show up in the test i listed above in the plugs for that rotor not firing, or firing erratically.

rickeo

iTrader: (1)

Well. I don't know if i'm more upset that I didn't just do this test myself of relieved/happy that this ordeal is over with.

The tech swapped the BHR coils for my older OEM ones and they can't get it to act up after driving it for 20 minutes.



I suppose I'll talk to Charles and see if he wants to take a look at the coils. I'm about to leave work to go pick up the car so If i left out any details just let me know.

9krpmrx8

iTrader: (46)

Well there you go

viprez586

iTrader: (5)

Glad you figured it out.

Contrary to most instances - I've had cars misfire badly(due to worn out coils) yet not set any codes. At least not immediately.

Hell, you sneeze on a Hyundai coil and they're f***ed!

paimon.soror

iTrader: (15)

awesome. Glad it was an "easy" fix.

rickeo

iTrader: (1)

Easy technically? Sure. Easy financially..? Not so much! At this point, i'm glad my car is running well again. Pissed because I tested the BHR's using the preferred method and they all checked out earlier that weekend.

It wasn't until this Monday, right before It went on to the flatbed to the dealer that I finally got a blinking CEL and by that time, I wasn't going to pull it all apart to do any more testing. What was going through my head was "the BHR coils tested OK, they're all firmly connected and I just replaced the spark plugs". Just a shitty situation all around that was compounded by this being my DD and needed to make quick decisions.

**** happens. You (hopefully) learn from it and move on.

Now, when I picked it up from the dealer, the service writer (good guy, really. Lee @ North Penn Imports - Mazda) had the compression numbers written on a paper that they were keeping for their records and said the actual document was back in the shop still. One face of rotor 2 scored a 7.3 but he didn't have the RPM it was tested at so who knows. The rest were between 7.5 and 7.9. I have to assume they are measuring that in kgf/cm2 I'm going to call in a bit to see if I can pick up the actual document that has the rest of the testing specs. I was not in the frame of mind when I picked up the car to do it then.

I'm emailing Charles @ BHR about it and see what he wants to do. If he can't help me out, I understand that I've had the coils for over a year and **** happens, even with an "upgraded" part. Everything can fail and I understand that.

9krpmrx8

iTrader: (46)

Definitely make sure you get the actual results, I have seen many dealers try an fib their way out of that. But if you paid for the test then you deserve a full report.

nycgps

iTrader: (1)

I always recommend people to just use oem coils

Glad it was an easy fix, sucks that u gotta pay the tow and dealer for nothing

kevinande

This is I think the third thread I have read where someone had BHR coils and were pretty sure that there was no way that the coils could be the source of the problem. From what I have observed it is a good product, but if the signs point to coils, you may want to check them regardless of where you got them from. I personally run OEM and change them regularly. I even keep an old set around for testing purposes.

RIWWP

iTrader: (2)

He actually did check them, if you read the thread he specifically stated that twice.

His test just didn't uncover the problem.

rickeo

iTrader: (1)

Yup, which is part of where my frustration came from. I bet you though, if I checked them for a third time on Monday when i finally began to get a flashing CEL (or CEL at all for that matter) I would have found something... I definitely, do NOT believe something can be infallible just because its considered "better" then something else. They're all still mechanical/electrical items and can fail just the same.