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Discussion Starter · #1 ·
As today, my mx6 is still running very rich. I've replaced a number of things which I'll list below.

-Spark plugs (bosch fusions, which came to $75)
-Distributor (year old)
-Spark plug wires are in mint condition, but aren't original NGKs
-Bosch o2 sensors
-Coolant temp sensor
-Magnaflow cat

I'm confused now, everything ignition wise has been replaced, so what else can it be?

The only thing I haven't changed is my fuel filter, but would this cause me to run rich, causing the motor to bog upon acceleration, and lots of black smoke? :smokin:

Then there's the VAF....

Any ideas???
 

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i dont no much about it running rich
but i do no those platinum plugs do not work good at all on mx6's
they made mine run like crap so i returned them lol
 

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Discussion Starter · #3 ·
Can't be, I had copper cores in there before and it still ran like this.
 

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no fault codes?
 

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if it bogs on acceleration, check your cap and rotor. it doesnt seem like the motor's getting spark...cap and rotor should be replaced at least once a year. i do it twice just coz im weird...

also, chef's thing on fuel pressure is right on too. if your fuel isnt getting in, youll bog.
 

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Discussion Starter · #7 ·
Ya but I'm getting too much fuel, that's the problem. I have so much black smoke coming out my tail pipe that people change lanes behind me. I might have over exaggerated that a bit, but it'll blow black smoke when I'm hard on the throttle a lot, like after slowing down while coming off the highway it'll run really rough.

I pulled my cap off 2 days ago, the cap and the rotor look brand new. I had a mechanic look at them as well and he said they look fine and to just take some sand paper and brush the metal contacts.

I filled up with premium last week and I've only travelled 267 kms, now I'm on empty. I have no leaks anywhere, the car is rust free.

Ahh this is driving me nuts...you guys must understand because this has to be a thing with a lot of mx6s. I can't be the only one thats having this problem.

Oh and when it starts acting up I know because once I start braking, the revs will stick at 1,300 and make it very annoying and hard to brake, then if I blip the throttle it'll bog a bit. Ive almost been hit by cars while trying to make left turns and having the car almost stall....this has to end, I love the car I just wish I could figure it out!!
 

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running rich is not necessarily an ignition problem. if the things you've done ... the 02's were a good call...the rest i dunno.

If you're haning with a v8 aurora you don't have a serious ignition problem.

i'd take a quick look at the fuel system....just because the body doesn't have rust doesn't mean your fuel lines don't. I lost a brake line in my 626 and it has very little rust on the car.

seems to be a sensor type problem to me....i'd make sure you tps is within spec, as well as the vaf...if your idle is screwy i'd look at the IAT as well

so annoying when you have a problem who's solution is not apparent. 267km's to a tank...thats redic. I get pissed if i'm even close to half a tank at the mileage
 

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i say try a known working vaf and get new cap and rotor. check if the cone in your vaf moves freely at all angles. when it closes it should make a loud plastic to plastic click noise. if it's a soft noise, then it's dirty and get a different vaf
 

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Discussion Starter · #10 ·
Thanks guys, ya it's very annoying and expensive too. I took my filter off my vaf yesterday and the cone was kinda jittering, it would sit still then fluctuate a little bit while I'm watching it. I took the vaf off entirely and unplugged it to see if that would change anything, it just made it dump black smoke out the exhaust on idle (which never happens) and it was idling at about 300. So clearly I can't delete the vaf....or can I?

Anyways, I'll get somebody to adjust the tps, and vandejm what's the IAT? Is that the same as the IAC?
 

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Discussion Starter · #12 ·
Ya then that's not an option. So what are the symptoms of a failing vaf? I wanna know for sure that it's the vaf and not something else.
 

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i had erratic idle issues with my car. i replaced my tps and it fixed a bunch of issues. not that my old one wasn't working, it was just working in a weird way, so I'm suspecting it was out of spec, but close enough to make me think it was operational. that didn't fix everything. my car didn't idle perfect until I swapped my vaf.

swapping my vaf was the last thing I thought of as it gave me symptoms of making me think my IAC was screwing up and I even changed my throttle body/IAC valve and timed the car so many friggin times thinking I had messed up. Nothing worked until the vaf was changed. There's no definite answer for it until you eliminate possibilities one at a time

Ya then that's not an option. So what are the symptoms of a failing vaf? I wanna know for sure that it's the vaf and not something else.
 

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Are you getting any codes? Have you set/adjusted the timing? Only thing I would've replaced is O2sensors. If you're not getting codes and the engine's not dying randomly, I think it' just timing issue. Get out your diagnostic wire and the timing lite.
 

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don't forget the 12mm wrench :p thing is, even if he does his timing, and the issue is with his TPS or with the vaf, timing the car perfectly so that it idles correctly will be impossible

Are you getting any codes? Have you set/adjusted the timing? Only thing I would've replaced is O2sensors. If you're not getting codes and the engine's not dying randomly, I think it' just timing issue. Get out your diagnostic wire and the timing lite.
 

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Discussion Starter · #16 ·
Well I don't think I'm going to adjust anything yet, I can check the timing though. As far as codes go, I have never seen the check engine light come on, other than when it everything illuminates while starting the motor.

I've hooked up a snap-on reader to it to try and get Something, but nothing came up. Should I just try a different VAF even if there are no codes? Or would there have to be a code in order for it to be failing?

I swear, this motor relies on way too many electronics and sensors.
 

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Discussion Starter · #17 ·
So do you guys think it's the VAF?
 

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how do you know you're running rich? do you have a gauge? we need more information. it could be anything from an exhaust leak, faulty cat, intake unmetered air leak, corroded wiring (hey i've seen some crazy stuff), or bad ECU
 

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Discussion Starter · #19 ·
Well my cat is brand new, it's a magnaflow. My exhaust is brand new, every single thing from the front to the back, exhaust wise, is brand new. I blow black smoke where ever I go, not constantly but when I stomp on it. It's running rich, trust me. I sell car parts and theres a garage attached, every time I bring it in they always smell my exhaust and say that it's running rich.

This is all the information I can give you guys, I dont know what else there is...if it blows black smoke its running rich. If it smells like raw fuel it's running rich. If I get 267 kms to a tank on premium, it's running rich. I've listed everything I've replaced, I forgot to mention the coolant temp sensor though. So I'm pretty much down to the VAF and timing.
 
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