steamer99

Hi Guys & Gals,

I tried to search, and the tried posting in the troubleshooting section before making this post.
The info on my car: I bought it last July, and then put it away for about 4 months of winter, so I am just getting to know it. 2006 GT, 86,600kms, the PO said that the coils and plugs were new last year (about 10,000km ago), I can not get a compression test since the closest rotary compression tester is about a 6hour drive away. The Check engine code is PO037 that I believe is related to the cat delete.

The Symptoms:

1. at idle it smells like it is burning very rich (may be a rotary thing it is my first)
2. at moderate or full throttle it stumbles around 5500 RPM
3. at less than 1/4 tank it will not keep running for more than about a minute.

As you can see in the first video ( ) it will pull all the way to redline at light throttle, but in the second video ( ) you can see it stumble at moderate throttle. since the check engine light is not flashing I assume that it is not a missfire, and I am thinking the fuel pump but wanted to see if any of the smart, experienced people here could confirm or point me in another direction. Just before I put it away for the winter it started but I thought that I had just gotten a tank of bad gas, so I ran it out and put good premium gas in it with fuel system cleaner in the tank. I also premix about 4oz each tank.
Let me know if you need any more info, and thanks in advance.

Steve

CaymanRotary

Reset the ECU. Your CEL for the rear O2 sensor wont cause this issue.

1) With the key in the off position, press and hold the odometer reset button and turn the key to on;
Continue to hold the odo button until the odometer reads "TEST" and then release.
2) Turn the key to off and repeat step one.

This will reset the entire PCM except the KAM which contains the sensor profiles amongst other things. You can reset it with the familiar procedure:

1) Turn the key to on
2) Depress the brake pedal rapidly 20 times in a row until the oil pressure gauge sweeps to halfway and back again.

Give it a shot. Not 100% sure will fix but it may. Plus it doesnt cost anything to try it. After resetting the ECU, allow to idle for about 5-7 minutes for ECU to relearn idle.

Diinj27

sound like fuel pump is going
Had that sort of similar experience. Car would run fine for 5 - 10mins and then won't rev pass 4k-5krpm and Stall or no throttle response pass 4k rpm. Had to wait fuel pump to cooldown and start again then drove slowly home.
Bad fuel pump is the result of running below 1/4 tank
Remove the rear seat and listen for fuel pump noise. Bad fuel usually make like bearing or starving pulse sound.

Blackwell

You can have my old one if you can make it down to Kamloops. I went a up to a 255lph.

steamer99

Thanks CaymanRotary, but that seems to have only lessened the "rich" smell in the exhaust at Idle, no improvements in drivability :-(

CaymanRotary

Was worth a shot. As others have mentioned could likely be a fuel issue. May not be the pump though, you can get it tested with a fuel pressure gauge to know for sure. Could just be a clogged line.

steamer99

Hi again, while waiting to get the fuel tank low enough to pull the pump I started going through the other troubleshooting steps in the FSM. So I have ruled out:

1. Vacuum leak (16.9" wc) min acceptable value :-(
2. Air cleaner
3. SSV malfunction
4. Fuel pressure at idle (59.8 PSIG)

When I tried using "Torque" on my phone and my bluetooth OBD reader to check the function of the drive-by-wire system I got the attached graph when giving the car full pedal in 1st gear and getting the malfunction.

Full pedal applied
It looks to me like I have a problem with the throttle actuator, Can any of you gurus confirm this? Also is it normal for the pedal to only register between 32% and 78% ?
Thanks again for your help, this is a great fourm.

Loki

iTrader: (1)

Normal for the pedal to register not the full range.
I suspect the car is responding to something by moving the throttle, rather than that being the root cause. You would have other codes if the throttle position was changing independent of the ECU input.
What are the other indicators like? AFR, Airflow, fuel trims.

P0037 is the heater circuit in your rear 02. If there is no rear O2 that would be why. If it's still there and plugged into the catless pipe, then it's not working properly anyway.

CaymanRotary

Hmmm... I'm a bit stumped to be honest. As mentioned, if there were an issue with your throttle there would be a code. Just never had an issue like this before and without being there it's tough to say. Is your ignition system recently serviced (plugs, coils, wires)? I doubt this is the issue but next thing I would look at. Doesn't seem ignition related but maybe. AFR's would be good too as you only know fuel pressure is correct at idle.

steamer99

Thanks guys, The previous owner said that the ignition was new (about 5000km before I bought it) and I have only put about 5000 myself. also since the MIL is not flashing I assumed (from what I have read) it was not ignition. I am planning on doing the red-neck compression test then will do a couple of runs with a trend for the AFR, Air flow rates. As far as I know fuel trims are still OEM, also the PO said that the cat had been gutted so not that. Any other sensors I should be looking at?

TeamRX8

iTrader: (25)

you need to know fuel pressure when the problem is occurring, the reading at idle is deceiving due to the way the fuel pump/siphon module assembly is designed. Not running below 1/4 tank is almost always indicative of a bad fuel pump, if for no other reason than it’s too weak to pull fuel over from the other fuel tank saddle and the pump side is running empty. The one other possibility though is the high speed/pressure fuel pump relay. Because if this is bad it will always be running the fuel pump in the low speed/pressure mode, which is one of the reasons you can’t rely on the fuel pressure reading at idle.

TeamRX8

iTrader: (25)

the other thing I forgot to mention is you should be able to read the AFR during that situation too. Probably easier indicator than fuel pressure. You can run a jumper wire across the fuel pump high speed/pressure relay terminals to test that part of it easily.

Blackwell

The access for the fuel pump is under the rear seat you don't need to lower the tank.

steamer99

Hi guys, thanks for the help so far, I ordered a tool to remove the fuel pump. I also did another run recording the AFR in "Torque" there seems to be a big separation of "commanded" and "measured", which I think is a problem. Also, the engine load seems high to me I would not think that it would go to 100% pulling in 1st gear. This las time a new indication came up the traction control light started flashing. This car seems to be moving from "My Precious" to"The Bi**h" I now have the red "Key" light. So I need to take a few days break as every time I work on it something else goes wrong. :-(

TeamRX8

iTrader: (25)

sounds more like a fishing expedition where you have no idea what it is you’re actually trying to catch.

The commanded doesn't mean anything, what is the actual afr value during the condition you’re experiencing? If you actually want help you have to provide us with real information rather than vague references and making determinations on things you don’t fully understand, such as engine load. Yes, it can hit 100% and higher in 1st gear.

Not trying to be insulting or demeaning, but nobody can help you if you’re going to be all over the place doing your own thing. We suspect a fuel pump and need more information before making a final determination, but you went and spent money on a tool you don’t know if you need or not yet. So far it’s like trying to take a puppy out bird hunting for the first time.

steamer99

Thanks for the splash of water, I see that I forgot to attach the pictures that I was referring to with the numbers that you want in them.

AFR with engine load

AFR alone

Sorry for being all over the place, This is the first rotary and most electronically controlled car that I have worked on. Some of my scattering is due to trying to read up and not ask stupid questions (that is apparently NOT working). I have been trying to work through the "Quick Diagnostic Chart" in the FSM which is why I checked 1)vacuum, 2) Air cleaner, 3) SSV, 4) fuel pressure, (looking back I see I put that one in wrong it was actually just pump pressure with out the engine running because I do not have a "T" I just disconnected the line and hooked up my fuel pressure tester) and now I did get the APV checked, (resistance and continuity only). Also there is no oil in the area of the MAF but I still took it out and cleaned it with "Sensor Cleaner".

I also read the following tidbits on the forum that have caused some of my inconsistency, 1) that when the computer sees 100% load it may cut fuel, and 2) "the first thing to do is a compression check". I did try the suggested (elsewhere not on here) analog test with my phone as the video recorder but do not trust my results, and am trying to find a tester that is closer than a 5 hour drive away from me, as the car will not likely make it there.

So in humility I ask what sensors (must be able to access them through an android app like Torque) and I will get a graph of them and hopefully remember to attach them when I reply.

Thanks again I do really appreciate the help.

TeamRX8

iTrader: (25)

no need to grovel either, sorry if it seemed a bit harsh, only trying to help, otherwise we’re equal in my eyes

super lean AFR if I’m reading that correctly, better not be throttling on it hard any more unless testing in short bursts

definitely looks like a fuel supply issue. Have you any way to confirm fuel pressure under load? That will help pinpoint between fuel pump and injectors. Fuel pump seems likely. However, I mentioned the fuel pump high pressure/speed relay (top RH corner in diagram below). Do you understand how to test or jump-wire it?







.

steamer99

I currently have no way to test fuel pressure under load, too bad Mazda did not put in a sensor that I could read in Torque :-/

I made a couple of runs with the high speed relay jumpered,


Not sure if that looks like a normal MAF reading, as you can see the by pass did not help.
Also I'm not sure if this graph is useful, but I had the program on when the car stalled, so I thought I would include it.


I also noticed this section of the graph where it looks like the MAF is not reporting, not sure if it is the MAF itself, the WiFi OBD reader, or the Torque app.



I'm still thinking fuel pump, but starting to wonder if it is the MAF. (yes my wife says I have ADD)
Thanks

TeamRX8

iTrader: (25)

well I can’t tell much of anything from this. I prefer spreadsheets where I can see the actual numbers rather than try to figure out what the value is over to the side, especially when it’s scaled too far down without any reference lines. (cough, cough)

it appears to be around 20 AFR under WOT. You need to quit doing that for extended periods.

that app is not going to solve this and without the proper tools all anyone can do is guess. If you have to guess then the fuel pump guess is as good as any.

Loki

iTrader: (1)

I don't think that O2 sensor is reading AFR correctly. What does it show while sitting still at idle? I don't see how the car would be running at all flatlined at the end of the readable lean range.
The MAF not providing any signal is pretty weird too. I agree with Team that you need to stop doing your testing with the foot on the gas pedal. Way too many things go on while you're accelerating to make sense, especially because we don't know what inputs you give it.
Can you do a log of AFR, rpm, throttle position, calculated load, airflow g/sec and coolant temp while the car is idling still, and another cruising at steady speed around 4000rpm?
If you can attach the data export in a file alongside the graphs, it'll be easier.

And, this might sound silly, but check if your battery terminals need cleaning. You'd be surprised what dirty terminals can do.

steamer99

Thanks Loki,

here is the idle export file, for some reason the program did not save the one when I went for a drive. I will try again another day, it was stalling and would not run for more than a couple minutes at a time. also I decided to check the codes and there are some new ones, so here they are:
Current Fault Log
------------------
P0037: HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
P0410: Secondary Air Injection System
P0411: Secondary Air Injection System Incorrect Flow Detected

Pending Fault Log
------------------
P0171: System too Lean (Bank 1)

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
U0073: null
U1900: null

steamer99

OK Loki and anyone else interested:

Here are a couple of trends one at idle, and one at approx. 4000 rpm I have included the data in .CSV format, the complete run (over 1000 sensor sweeps) and sections at idle and approximately 4000 rpm.
Hopefully this will help, I am now waiting for the tool to remove the fuel pump.

steamer99

Hi all,
Update: I finally got the tool (and modified it to fit the RX8, When I got the pump assembly out I found that the suction sock was plugged with some black sludge (see pix), I cleaned it as good as I could and put in a good used pump, the hesitation and stalling is gone. Unfortunately a compression test found all chambers to be about 85psi so the motor is on it's way out :-(

inside the bowl

The plugged sock 1

The plugged sock 2

CaymanRotary

Plugged fuel sock will definitely cause issues. 85 psi @ 250 rpm adjusted for altitude?

steamer99

The compression is an estimate from two things, I tried the regular compression tester trick and the needle bounced to about the same location (just under 80psi with 200-220rpm according to the "Torque" app) on all 6 chambers, not trusting this method I found a local shop that claimed to be able to test the compression on a rotary. What I got was 4 readings (1 from each sparkplug hole) not 6 so the reading is the best chamber but since all my readings were very close I am believing them to all be the same or within a couple of PSI. Front rotor 80, back rotor 85 all readings at 250rpm but not corrected for the elevation of approx 1800 ft above sea level. I do not think that the altitude correction would bring them up to the 98.6 minimum from the FSM.