The O2 Saga Continues

[MikeyLikesIt]

OK, so I installed the WBO2 sensor over the weekend, and what it appears to me now is that I'm guessing on what is called 'tip in' on the throttle, the gauge drops to about 10.0 as soon as I hit positive boost, and stays low (10-13) until the boost tapers off. Is this normal operation? Or am I constantly supposed to be running lean on boost?

I'm on a budget, so I may have a line on a used Voodoo box, so at least I can adjust the fuel and it also has a built-in O2 clamp. Or is this the wrong path to take?

At least until I can afford a PC Pro and not have to disassemble the box to make any changes.

Thanks to all in the help and advice.

Mike
:tank:

[chuckerants]

What are you using for fuel now?

Yes, the Voodoo box is not what you want.

[MikeyLikesIt]

I have a regular Powercard now.

What do you suggest?

[MikeyLikesIt]

Or are you just suggesting a Powercard Pro?

[chuckerants]

I can't tell you what to do, but this is the progression of EM's I've had:

1. Powercard
2. ELF
3. PC Pro

The ELF was better than the PC in that it was adjustable, but not by much. The Voodoo box is much like the ELF is terms of adjustability.

The PC Pro is in fact light years better than the PC and without going to a full ECU, IMHO is as good and simple as it gets. I understand that it costs $500, but again, IMHO, it's worth it over the Voodoo.

[chuckerants]

BTW, 10:1 AFR is richer than 13:1.

So unless you are experiencing other "symptoms", you are seeing what should be happening.

[MikeyLikesIt]

BTW, 10:1 AFR is richer than 13:1.

So unless you are experiencing other "symptoms", you are seeing what should be happening.


OK, so I am reading it backwards. (duh)

I'll keep searching as to why I am still getting the check light...

Thanks

[chuckerants]

OK, so I am reading it backwards. (duh)

I'll keep searching as to why I am still getting the check light...

Thanks

What code are you getting with your CEL?

BTW, I didn't have a WB when I had a Powercard, but IIRC, mine did the exact same thing your car is doing and at tip-in, due to all that fuel would lurch and hesitate a little.

[Tom @ Fast Forward]

Refresh my memory, which CEL are you getting?

[BlownMX5]

...this is the progression of EM's I've had:

1. Powercard
2. ELF
3. PC Pro



Huh, what a coincidence, Chuck! My progression was exactly the same with one added item:

1. Powercard
2. ELF
2.5 New engine
3. PC Pro

In my case, my ELF was um, not better than my PC. It sure makes a dandy paperweight though!

Pat.

[chuckerants]

From what I gathered, the very early ELFs actually worked - like mine.

Huh, what a coincidence, Chuck! My progression was exactly the same with one added item:

1. Powercard
2. ELF
2.5 New engine
3. PC Pro

In my case, my ELF was um, not better than my PC. It sure makes a dandy paperweight though!

Pat.

[BlownMX5]

I know, I'm just bitter :mad:. I like to trash the ELF every chance I get.

[MikeyLikesIt]

Refresh my memory, which CEL are you getting?

Lean bank 1 P0181, I believe. But I did also have a P0131 code which is a bad O2 sensor. I cleared it yesterday, and it ran fine both back and forth to work, but I'm pretty sure, sitting at idle or in short, stop and go traffic, the light popped back on. I will have to see if I have both codes again tonight.

I will commit to the PCPro, but I want to make sure it will cure my issue.

Someone is willing to sell me a used Voodoo box for $175.00, but listening to you guys tells me not too :confused:

Thanks

Mike

[Tom @ Fast Forward]

FWIW, I have replaced several voodoo cards on FM turbos with PC-Pros. The typical response is 'what a difference'. Check here for turbo and PC-Pro. Also check for the same on mnet. You may be stepping out of the frying pan and into the fire.

[MiataMTF]

On my overdriven JRSC M45 - the regular Powercard ran RICH at WOT and more-or-less lean elsewhere. I was NOT happy with it. I had heard of the issues with the ELF and Voodoo/O2 clamp so I skipped that progression and went straight to the PC-Pro - WORKS FOR ME!.

[MikeyLikesIt]

OK, from what I can tell now, and I need to do a bit of research to better understand it myself, is at idle, the O2 gauge reads, pulsing, between 14~17. Once I push on the gas, it drops to around 10-12 and works it way back to 14 or so once I reach crusing speed. Go WOT, it drops to 10 again and as boost comes off, back to ~14.

Does this look right? Every time I reset the CE light after changing or addressing something, it comes back basically sitting at idle or close to it.

My next steps are plugs, stock O2 sensor, fuel pump and filter. I have the pump and filter (just need to make the commitment to pulling the fuel system apart), and I'll have to order the plugs and O2 sensor.

Does it make sense to vid the O2 gauge and review it? Or do I find a dyno and have it recorded?

Thanks all,

Mike

[Tom @ Fast Forward]

Mike,

Sitting at idle or cruising down the road at steady speed, the )2 should oscillate from the low 14s to the mid to high 15s.

When you put your foot to the floor, it should go to around 12 and stay there, more or less. When you say it goes to 10, does it simply stay there or go to 10 and rise to 12 as you get higher and higher in RPM and boost?

[MikeyLikesIt]

Yes, it behaves as you state.

So maybe it is a bad O2 sensor?

I still want to do the filter and fuel pump.

Whadda ya think?

[Tom @ Fast Forward]

How many miles on the car? My front O2 finally gave up but it was over 100,000 miles. If it is oscillating as I stated, the O2 should be good? That is normal oscillations.

[MikeyLikesIt]

The car only has abot 50K. I did get to open it up a bit on my ride this morning, and it did drop to around 10 or so when I went to boost, then stayed 12-13-14 while still under boost. But like I said it seems like the CEL comes on in nromal, stop and go traffic, maybe even at idle. I'm going to see if I can pick up a O2 replacement for the front seneor and see what happens.

Thanks

Mike

[ROZ]

Tom,
Give Mike the link to that video you sent me, the one that shows the oscillation at idle.

[Tom @ Fast Forward]

Andrew,

Do you have any recollection of the file name?

[ROZ]

:driving:Here it is...
http://www.fastforwardsuperchargers.com/13-8.wmv

[MikeyLikesIt]

While I wish I could try and test that on a drag strip, I think it's close to the way mine behaves... :stuart:

Another question: When sittimg at a dead stop and idling, it blips between no reading (---) and 18 or so. Is that normal as well?

I'm on the search for a replacement O2 sensor today...

Thansk again guys,

Mike

Hey Tom: ever make it out to the East coast? I got a place for you to stay...

[ROZ]

:chillpill:

Jazz - it's the calm before the stttooooooorrrrrmmmmmmm..........:gnorsi:

[Tom @ Fast Forward]

Mike, we don't get much beyond Cleveland and Detroit anymore.

We have space here for weary travelers as well. Miatafiles are welcome anytime.

[MikeyLikesIt]

OK, swapped out the O2 sensor. Reset the CEL, and got it back withing 15 minutes of driving :censored:

Next is plugs. Did wires a month ago trying to troubleshoot the issue. Fuel pump and filter are also on tap. Possible clogged injector? Time for a fuel rail?

Suggestions?

Thanks,
Mike

[chuckerants]

Mike,

What year is your car?

[MikeyLikesIt]

Mike,

What year is your car?


2000 SE. What are you thinkin'?

[chuckerants]

I just want to make sure I understand the problem.

So far, you have a persistent P0181, but it doesn't sound like you have any driveability issues correct?

And you replaced the FRONT 02 sensor?

BTW, I don't even see P0181 listed in the 99 Mazda Factory Manual.

[MikeyLikesIt]

I just want to make sure I understand the problem.

So far, you have a persistent P0181, but it doesn't sound like you have any driveability issues correct?

And you replaced the FRONT 02 sensor?

BTW, I don't even see P0181 listed in the 99 Mazda Factory Manual.

Sorry, it's a P0171. Bank 1 Lean. And, yes, it was the front O2.

[chuckerants]

According to the Manual, there are about 20 items on the diagnostic tee. The first few are:

- FI Malfunction
- Fuel Pump Malfunction
- Fuel filter clogged
- Fuel delivery hose clogged or leaking
- Pressure regulator malfunction
- Pulsation Damper malfunction
- Ignition coil malfunction

Front O2 sensor is down the list even further.

When was the last time you changed the fuel filter?

[MikeyLikesIt]

According to the Manual, there are about 20 items on the diagnostic tee. The first few are:

- FI Malfunction
- Fuel Pump Malfunction
- Fuel filter clogged
- Fuel delivery hose clogged or leaking
- Pressure regulator malfunction
- Pulsation Damper malfunction
- Ignition coil malfunction

Front O2 sensor is down the list even further.

When was the last time you changed the fuel filter?

How about... never! I do have a filter and a new 255lph pump. I just don't like messing around with the fuel system. Oh well, looks like my weekend project is set.

Thanks

[chuckerants]

The Fuel filter is pretty easy if a little messy.

Even after depressurizing the fuel system, you can still expect to get gas coming out. My advice, wear a disposable T-shirt, no watch, and get an oil change pan to catch excess gas flowing out.

Also, try to get new clips for the fuel filter. Not all filters come with the new clips and though I was able to reuse my clips, I can see it's very easy to break the old clips off.

Additionally, exhaust and vacuum leaks were also listed so you can check that when you're under the car.
How about... never! I do have a filter and a new 255lph pump. I just don't like messing around with the fuel system. Oh well, looks like my weekend project is set.

Thanks

[cmetzner]

Before replacing the fuel pump. I would check the fuel pressure. Should stay above 65psi when you accelerate. Then, I think, the system should hold pressure after the car is shut off for at least 5 - 10 minutes. If it does, the pressure regulator is OK.

Change the fuel filter if you have not done so in a year. I do not follow my own advice and change every two years and there is a noticeable difference in initial acceleration. I never had a car that was this sensitive to fuel filter changes. I have a new filter sitting on the bench waiting for me to screw up the desire to have fuel dripping down my arm.

-- Chuck

[Tom @ Fast Forward]

Actually, the 99-05 should be pretty steady at 56-62PSI. 60-62 is pretty common.

[chuckerants]

That reminds me, I think it's about time I replace my FF too. I miss not being able to wear my watch for two weeks afterward. :)Before replacing the fuel pump. I would check the fuel pressure. Should stay above 65psi when you accelerate. Then, I think, the system should hold pressure after the car is shut off for at least 5 - 10 minutes. If it does, the pressure regulator is OK.

Change the fuel filter if you have not done so in a year. I do not follow my own advice and change every two years and there is a noticeable difference in initial acceleration. I never had a car that was this sensitive to fuel filter changes. I have a new filter sitting on the bench waiting for me to screw up the desire to have fuel dripping down my arm.

-- Chuck

[MikeyLikesIt]

Changed fuel filter. Not very fun, but it's done. Runs better, but CEL still came back on. I did a look at all of my vac lines on top of the motor, didn't see anything.

I am running a hotside, with Tom's BTB. There is one fitting that sits on the bottom that is real close to the exhaust header. Maybe it's come apart down there.

On to the next...

Mike

[MikeyLikesIt]

Current status from chuckerants suggestions. Fuel pump was done last (255lph) and it ran fine for 2 days, then the CEL popped back on.

- FI Malfunction - Searching for a used set
- Fuel Pump Malfunction - Changed
- Fuel filter clogged - Changed
- Fuel delivery hose clogged or leaking - Need to look, but not confident
- Pressure regulator malfunction - Haven't changed ($167.00!)
- Pulsation Damper malfunction - Needs research - Don't know where this is located
- Ignition coil malfunction - Changed

I am ISO a good set of used injectors to swap those out next. If that doesn't fix it, I may have to finally bow down and admit defeat and take it to a shop. I'm not sure else what to do. Besides the fact that the inspection expired back in August...

Mike

[pumpkin]

Look real close for a small leak somewhere in the line/hose between the MAF and TB. I had the same 0171 and found a small tear in the convoluted intake hose.
JD

[Johan]

Have you solved the P0171 mystery? I'm also getting the code. Just got it the second time today. I was cruising in town and had it in boost very now and then. I then gave a friend a ride back home and when we stopped at his place the car was idling for a couple of minutes and that just caused my CEL to lot up! Now when I'm thjinking of it I think the first time I got the P0171 it was also idling. Strange. Seems like I have to purchase a code reader.

Johan
===================
2002, 170WHP Coldside

Current status from chuckerants suggestions. Fuel pump was done last (255lph) and it ran fine for 2 days, then the CEL popped back on.

- FI Malfunction - Searching for a used set
- Fuel Pump Malfunction - Changed
- Fuel filter clogged - Changed
- Fuel delivery hose clogged or leaking - Need to look, but not confident
- Pressure regulator malfunction - Haven't changed ($167.00!)
- Pulsation Damper malfunction - Needs research - Don't know where this is located
- Ignition coil malfunction - Changed

I am ISO a good set of used injectors to swap those out next. If that doesn't fix it, I may have to finally bow down and admit defeat and take it to a shop. I'm not sure else what to do. Besides the fact that the inspection expired back in August...

Mike

[Tom @ Fast Forward]

It is coming from STFT for some unknown reason?

How many of you with that problem are 2002 and hpw many are other 01-05 years?

[MikeyLikesIt]

Tom: STFT?

Mike is a 2000. I'm now in the process of adding a bigger bore dual feed fuel rail and some MSM injectors I had cleaned and bench tested to see if adding more fuel will do the trick. I also plan on cleaning the intake manifold while I am in there...

But I can tell you this: I removed the belt for the S/C, effectively taking it out of the equasion.

My idle dip is gone, and I reset the CEL and see if I can get it to completely clear. My inspection was up in August, so I need to get it legal, as opposed to keep trying to troubleshoot at this point.

I'm wondering if I finally need to break down and go PC-Pro? If I understand correctly, the older PC doesn't add fuel at idle. This might be what's causing the CEL to come on at that point. Am I correct in that statement? Wil the PC-Pro account for this?

Mike

[Tom @ Fast Forward]

Neither the old PC or the new PC-Pro add fuel at idle. Some of the idle droop is caused by Short Term Fuel Trim. That is caused by allowing the ECU to continue to adjust fuel while in boost. The PC-Pro does prevent this. The old PC does not.

Adding larger injectors will simplt exacerbate the problem as it will allow the STFT to become even more negative. If you have an OBD2 scanner, drive it with the blower running for awhile and then check the STFT. My guess is it is somewhat negative when you come off boost and go to idle. The larger the injectors, the more negative trim has to be added to correct for the factory tables. When you lift, the ECU goes open loop, looks at it's open loop idle table for the proper timing and fuel and then adds/subtracts fuel according to the trim. As soon as idle appears to level off, it goes closed loop and re-corrects the fuel with the O2 sensor. Sometimes the time between those two operations is just enough to allow droop, or worse, stall.

While the PC-Pro does not add fuel at idle, it can stop the ECU from subtracting fuel enroute to idle.

[MikeyLikesIt]

So I've been running with the S/C belt removed, so I could clear the CEL completely and get it inspected. It ran fine for 2 days, but the CEL came back on again today... Damn! :frown:

So am I still looking at the same issue with the STFT? The old PC is still connected, but no belt is attached to the blower...

Mike

[Tom @ Fast Forward]

Did you confirm that it is the same CEL? With the belt off the blower, the card should be out of the picture. Let us know if it was the same CEL or different.

If the same, I would be looking at the CAT or the front O2 sensor.

[MikeyLikesIt]

Tom: Thanks for the call yesterday. I'll disconnect the PC when I get home tomorrow, and I've ordered a scan tool that will do a snapshot and live recording (I love my gadgets) and see what happens next.

Mike

[Tom @ Fast Forward]

Do you have a vacuum/boost gauge? If so, what is your vacuum level at idle? Should be 18-20" Hg.

[MikeyLikesIt]

Yep, it's around 20"

Mike

[Tom @ Fast Forward]

Just wanted to be sure you didn't have any vacuum leaks.

[MikeyLikesIt]

OK, I got the datalogger, and did capture, I think the 'snapshot' of the CEL. I won't be able to dump the data until I get home tonight, but I can look at it frame-by-frame from here at work. So, Tom, if there's anyhting in particular you want me to report on, let me know.

I also disconnected the PC and pulled the plug off of the injector on the Split Second box, although it's still wired in.

Thanks again,

Mike

[Tom @ Fast Forward]

It should show a whole load of PID codes. Let me have all that there are. The more data, the more likely I can tell what happened.

[MikeyLikesIt]

Here's the Freeze Frame data, but it's just one PID. Maybe I should pull the live data? It captured more frames...

[Tom @ Fast Forward]

That is very interesting.

STFT at 19.53% is what set the code. However, water temp is only 159*F. Did this occur just after a cold start?

Sounds like a fuel pressure problem. The injectors have to open too far to make the needed fuel. How long have you been running the kit with no problems? Items I would suspect:

Fuel pressure regulator
Fuel pump
Fuel filter
Front O2 sensor

[MikeyLikesIt]

This was at a cold start. The kit had run fine for a while, and I had been having intermittent CEL issues, but this one won't stay away.

Fuel pressure regulator - not replaced
Fuel pump - replaced
Fuel filter - replaced
Front O2 sensor - replaced

This morning, I disconnected the Split Second from the system. I have the fuel feed for the 5th injector teed right near the FPR. Could that be the cause?

If you think I need a new FPR, should I reorder a stock one?

Also, from reading the frame, what number is a good number for the STFT?

Mike

[MikeyLikesIt]

No, wait, is the FPR on my car back at the fuel pump? I just looked at one online, and I think that's where it's at?

[Tom @ Fast Forward]

99-05 FPR is back at the tank. Before you replace it, see if you can get your hands on a fuel pressure gauge and stick it on. It would be very helpful to know what the pressure does all the way to redline. I am not a great believer in randomly changing things.

[Tom @ Fast Forward]

Also, from reading the frame, what number is a good number for the STFT?

STFT moves around all the time. LTFT should be near 0 for stock injectors, stock FPR and stock fuel pump. STFT should not need to go farther than +/- 10% under those circumstances either. The problem is that your LTFT was high as well as your STFT. That indicates it was more than just an instantaneous problem. It had been drifting for awhile. That is what brings me back to the Front O2.

[MikeyLikesIt]

Also, from reading the frame, what number is a good number for the STFT?

STFT moves around all the time. LTFT should be near 0 for stock injectors, stock FPR and stock fuel pump. STFT should not need to go farther than +/- 10% under those circumstances either. The problem is that your LTFT was high as well as your STFT. That indicates it was more than just an instantaneous problem. It had been drifting for awhile. That is what brings me back to the Front O2.

I can put the orig. O2 sensor back on, but I just replaced it with a new one about a month ago, when this issue was already happening. What about the fuel dampener?

Mike

[Tom @ Fast Forward]

No. The dampener will have little or no effect.

[MikeyLikesIt]

So where would I put the pressure gauge? Close to the rail?

[Tom @ Fast Forward]

Anyplace in the feed line to the rail or 5th injector.

[MikeyLikesIt]

Is there a test valve I can attach to? Then I can buy a test gauge and run up the RPM's in the garage and check it.

[Tom @ Fast Forward]

I bought a test gauge from Autozone. It came with a hose for quick connect. However, they didn't fit the Miata. Then I tossed their hose and used a tee and some fuel injection hose. The hose is long enough to make it to the passenger compartment to watch the pressure as someone else drives.

The small button near the gauge and the clear hose, let you safely relieve the pressure back to a can instead of all over the car and floor. I think it was $30.

All we did was pull the hose off the 5th injector and put it to the tee and the short hose from the tee to the 5th injector.

[MX-Drew]

Just a thought Tom, did Mike reset the ECU after replacing the front O2 sensor?

[Tom @ Fast Forward]

No idea? Mike will have to answer that.

[MikeyLikesIt]

Other than removing the neg from the battery and pumping the brake a few times, is there anything else?

[MX-Drew]

No that's it.

My bright idea over. :biggrin:

[MikeyLikesIt]

Well, I finally broke down and took it to a shop to help me address the issue. It was a good thing I did. What the mechanic did was use a smoke machine and fed it into the intake. They found four leaks! :svengo:

They were in places I thought I had looked, but coudn't see them until they got 'smoked'. I guess I need better lighting in my garage... Nor did I think of adding a smoke machine to my tool box...

So far, so good, the WB seems to have settled out... now just waiting to see if the CEL will clear from the computer so I can get it inspected.

I'll update everyone, but thanks to all for your input and suggestions.

Mike

[Tom @ Fast Forward]

I still contend that there is no such thing as a small vacuum leak. :)

[MikeyLikesIt]

OK, I spoke too soon. The STFT is now stable as well as my A/F, but now I am getting a P0506, Idle Air Control System RPM lower than expected. It also comes included with a hellacious idle dip. Swell.

It seems to get better after a bit, but even after the car comes up to temp. Does the IAC have to be warmed up? Or is mine malfunctioning?

Mike

[Tom @ Fast Forward]

A minor adjustment of the idle stop screw might just fix that. Before you do anything else, I suggest you reset the ECU and drive it a couple days. The ECU needs to re-learn after all those problems. You need to drive lights on/off and AC on/off and combinations of those. See if the idle doesn't re-learn.

[MikeyLikesIt]

A minor adjustment of the idle stop screw might just fix that. Before you do anything else, I suggest you reset the ECU and drive it a couple days. The ECU needs to re-learn after all those problems. You need to drive lights on/off and AC on/off and combinations of those. See if the idle doesn't re-learn.

Should I do a full disconnect of the battery again? I did clear the error, but it came back.

I will do that tonight.

[Tom @ Fast Forward]

Yes. Pull the battery negative cable and pump the brakes a couple times and then put it back. Then don't do any adjustments for a couple days. Drive short and long drives if you can ( 5-10 minute and 30 minute) with AC on/off and lights on/off and combos.

Give the ECU a chance to start from scratch. Resetting the codes does not reset the ECU memory. Might actually be best to leave the CEL on and see if others come on as well. When you reset it, it takes a couple drive cycles and 40 miles to reset the CEL readiness indicators.

[MikeyLikesIt]

OK, so I've reconnected the powercard, 5th injector, with a new belt. I can go into low boost, but anything above 1/2 throttle, the A/F goes completely lean!

I have the old PowerCard, and have a green flashing light at idle and running.

Any ideas?

Mike

[MikeyLikesIt]

It never leaves the flashing green, even under throttle.

[MikeyLikesIt]

Another update: I am seeing boost at my gauge, which is split off of where the vacuum line that goes directly into the PC. Is the PC defective and not registering the boost? I don't have any lights lit on the PC but the flashing green...

[Tom @ Fast Forward]

Mike,

If you want another PowerCard to try, I have a couple sitting around that were working when removed and replaced with the PC-Pro. I will send you one if you wish. Let me know.

On the other hand, they are basically bullet proof. My guess is that you sed the clip on wire taps and eith have the worng wire(s) or the taps are not making good connection. THAT was the reason we added the pre-wired soldered harness to our kits. Only six wires but they were a real PITA to get properly connected.

[MikeyLikesIt]

Mike,

If you want another PowerCard to try, I have a couple sitting around that were working when removed and replaced with the PC-Pro. I will send you one if you wish. Let me know.

On the other hand, they are basically bullet proof. My guess is that you sed the clip on wire taps and eith have the worng wire(s) or the taps are not making good connection. THAT was the reason we added the pre-wired soldered harness to our kits. Only six wires but they were a real PITA to get properly connected.

I've double-checked my connections, and verified that I do have a solid vacuum line. But the damn green light never goes solid. If I was missing a connection on one of the injectors, I should have seen an error light.

So Tom, if you're still offering, I'll take one of the old PC units to test. Let me know cost and shipping. I'd go ahead and buy the PCPro, but with the holidays, I can't pull the trigger on it right now.

Thanks all,

Mike

[Tom @ Fast Forward]

Mike,

Email me your address where you want it sent. Don't worry about cost. Merry Christmas.

[MikeyLikesIt]

Well, I completely pulled out the PowerCard and took a look at it on a bench. Turns out there was a broken solder joint on one of the connections. I re-did the connection and wired it back in and it runs! Well at least for one day. Now I am getting a loud clicking sound out of the SC. Poop! Is it time for a rebuild?

Will this saga ever end?

Mike

[Tom @ Fast Forward]

No rush to return the one I just sent. Better safe than sorry.