If only I was as rich as my car is running...

[MaverickX3]

Note: Car atm is bone stock

I originally was going to post about my troubles with the car running stupid rich (maxing out) at idle but then figured it out and thought I would share the results. STFT were going down from -12 slowly to -25. It was soo much that the ecu could no longer compensate to remove fuel and my afr's were around 12.5-13.2 @ idle (approx 700 rpm) at best.

I blocked off the egr valve, tested the purge solenoid valve (plugged it to see if it was leaking), cleaned my throttle body, checked for any air leaks and made sure my maf was connected properly.

Hell, even my coolant temps, intake temps, maf voltage, maf mg/s and idle were fine.

Answer: Bad connection for the maf ground wire.
In the manuals, unless I read it completely wrong, the maf ground wire was on the opposite side of the harness (not A).

Removed harness and connected up the wires directly to the corresponding pins. In doing so and finding out the solution, I accidentally crossed the wires and then temporarily fubar'd my car. Oil control valve, purge, egr, maf were now out. FML. Luckily I tore into the fuse box the other day to trace what I thought was the maf ground wire. Found one of the shared lines going to the fuse box and traced it to the ENG BAR 15a fuse. Replaced and good to go! Just had to use one of my headlight fuses in the mean time as my spares were out.

What was soo messed about this that all of my PID's/ecu readings were within spec.

I'm now sitting in at about -3 STFT for a blip at worst but the car is usually around 0 and -1, right where it should be. Hooo.Ray. LTFT should now average out nicely for the first time ever on this car

[TriO]

this sounds like similar symptoms to what i'm having.... i'll have to check my wires/fuses.

Were your problems only at idle?

[sLow6]

Haha. Nice title.

[MaverickX3]

Yep. My fuel trims above idle were also a bit rich, but I haven't done any new logging since I fixed everything at about 2am this morning :P

There was a tsb for Mazda 3's about the ground being bad but their wiring is different (black ground, MS6 is white with blue stripe) in relation to the P2188 dtc.

[TriO]

interesting.... i'll check this out today as i was getting P2188 too.

Fingers crossed

[Chriscote]

im throwing p2178 and p0113

too rich at idle and air induction temp high i think.

[MaverickX3]

Originally Posted by Chriscote im throwing p2178 and p0113 too rich at idle and air induction temp high i think.

P2178
Too rich at off idle
P0113
IAC circuit high input

IAC one prob do to the ground being a little off from what I have checked out. The too rich at off idle almost sounds like a restriction. Check your vtcs or intake cam timing a hair off.

[Zero2142]

Originally Posted by MaverickX3 Note: Car atm is bone stock I originally was going to post about my troubles with the car running stupid rich (maxing out) at idle but then figured it out and thought I would share the results. STFT were going down from -12 slowly to -25. It was soo much that the ecu could no longer compensate to remove fuel and my afr's were around 12.5-13.2 @ idle (approx 700 rpm) at best. I blocked off the egr valve, tested the purge solenoid valve (plugged it to see if it was leaking), cleaned my throttle body, checked for any air leaks and made sure my maf was connected properly. Hell, even my coolant temps, intake temps, maf voltage, maf mg/s and idle were fine. Answer: Bad connection for the maf ground wire. In the manuals, unless I read it completely wrong, the maf ground wire was on the opposite side of the harness (not A). Removed harness and connected up the wires directly to the corresponding pins. In doing so and finding out the solution, I accidentally crossed the wires and then temporarily fubar'd my car. Oil control valve, purge, egr, maf were now out. FML. Luckily I tore into the fuse box the other day to trace what I thought was the maf ground wire. Found one of the shared lines going to the fuse box and traced it to the ENG BAR 15a fuse. Replaced and good to go! Just had to use one of my headlight fuses in the mean time as my spares were out. What was soo messed about this that all of my PID's/ecu readings were within spec. I'm now sitting in at about -3 STFT for a blip at worst but the car is usually around 0 and -1, right where it should be. Hooo.Ray. LTFT should now average out nicely for the first time ever on this car

My symptoms are about the same as yours. I installed my SRI from SURE and 100km after my ECU relearned my driving the CEL came on with P2188 and U2064. My STFT were -25% and my LTFT would start out at -13% and then as I let the car idle more plus driving around it would idle at a -20% LTFT. hopefully mine is the same with a bad MAF ground connection. I installed the stock airbox again but still my fuel trims were around -8% to -13% but not as bad as when I install my SURE SRI

[MaverickX3]

I've put everything back to stock again cept for a test pipe and blocked off egr via plate. LTFT sits at -10 and STFT goes from +1 and will taper to -6 or so. LTFT hasn't really changed from -10. I also regapped my plugs to the stock 0.032 and even added copper wires in the COP to rid of any possibility of ignition faults.

With the egr blocked off and plugging the purge line temporarily with my thumb it only leaves three or so things left:

1. Leaking fuel injector (fuel pressure is right on the money though) 2. MAF wires or MAF itself is bad or 3. An exhaust leak post block. Or 4. Bad 02 even though it reads fine :S

I did manage to pull and press in the maf ground which is the wire closest to the engine block (white with blue stripe). And no longer get the messed up fuel trims or P2188. Just the -10 LTFT I am working on now.

I might see if I can have a chat with a Mazda tech at my work (I work in IT at a tech institute) and find out what he thinks.

[MaverickX3]

Sooo things aren't totally fixed yet....

LTFT is at around -10 and popped up to -11 today. STFT might work itself down to -6 but LTFT still sits at -10. Hell, LTFT even went to -1 and then I saw STFT go to -16/-17 grrrrrr.

So the wire I plugged and pushed back in wasn't the one that was in a TSB for early Mazda 3's. I also looked at the connector diagram the wrong way (insert side of connector, not harness side). The wire in question is the SECOND one in by the engine side. Purple Blue or something like that.

I'm going to cut back and rewire as far down as I can go for my IAT ground wire (which was corroded) and re do the Purple Black wire that goes to the PCM.

Talked to the Mazda guy at work and nothing definitive yet. Just got to do some damn electrical work with this maf...fuuuuuuuuuu (electrical work was the one thing I NEVER wanted to do on this car. FML).

[FAUXSPD]

Any resolve on this? I've been throwing a P2188 for some time ...

Thanks.

[MaverickX3]

Fuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu

So aside from putting in a new alternator (voltage would drop a lot when car was hot, suspected bad diodes on alt) put on my Cobb TIP as I could make sure everything was nice and tight (no leaks) and ya...got the P2188 again FML.

I'm going to try to play with the MAF wires again and check for any leaks around the crank case breather. I might just have a bad maf after all this time.

[MaverickX3]

Unplugged all of the wires out of the connector on the MAF and then pushed them in directly to their corresponding pin. Everything seems a bit better now. I still might have to re-cut the IAT groud wire as I got a P0113 (IAT high voltage). So far just a U1900 code picked up by the AP.

[CW42]

My 2007 MS3 is stock and I've taken it in about 8 times with the "rich at idle" code. New #1 o2 sensor, MAP sensor and all injectors replaced. No luck. MAF has been cleaned twice. Seems to idle fine after sitting all night. Steady exhaust, smooth engine sound. After driving at highway speeds, then parking and starting the car a little later, start up has a strange noise that almost sounds plastic-like and like a pump or gurgling sound. Weird sound keeps pace with revs. Once at higher RPMs, car runs fine. Idle is rough and getting rougher each time I get the car back (since the problem isn't really fixed). have to find a fix before the car gets worse. Dealer is stumped and so am I.

[mrQQ]

i wonder if this has ever been fixed..