Time to play...Is my maf bad

[ND4MSP]

So I'm trying to troubleshoot why my car is running like ass. I threw a cel the other day and it ended up being a coil pack. Replaced that and the car still runs like ass. Its running like I have a major vacuum leak. Stumbling, no pickup missing when accelerating, idling real rough. But all of this may have occured at the same time.

So I unplugged my maf just for shits and the car idled a lot better. Now if I am correct the car goes into closed loop right?

So would this rule out the car still misfiring. Because open or closed loop it should misfire either way. Same thing with a possible vac leak. Shouldn't it still run/idle crappy regaurdless of the maf being on or off.

Or is it just the maf???? Help me thx Need to get back to(drive2)

[StreetStyleJPTI]

I had a bad MAF recently. Have you thrown the MAF CEL? When my MAF was bad, I would have to floor it for a few seconds before the car would respond. It would still drive like shit with sluggish response. Do you have a boost gauge? With a boost gauge, you could check to see if your vacuum is where it should be.

[Flspeed]

Yes, your ECU is in a sort of stand-by mode. I would look for vacuum leaks. What modes do you have?

[ND4MSP]

Believe it or not. The screen/diffuser in the maf housing was loose and facing out at a perfect 90 degree angle. So I'm assuming the intake air was being cut like a knife and being diverted around the maf sensor. Fucking crazy.

I was going to bump the old diffuser or no diffuser thread, because I've got a pretty good reason to leave mine out now.

[neox.286]

interesting, Ive had this same exact problem....however I replaced the maf with a buddies and it still didn't help it

sub'n...

[ND4MSP]

The cel was for a misfire in cyl 4. So I did a lot of reading, and before I wen't and started replacing this and that I decided to check the maf first. So after I posted here I went and grapped some maf cleaner for shits. So I found the diffuser like that obviously as I was pulling the airbox away from the maf housing. So it looks like a faulty maf can cause ignition/spark related engine lights.

My vac was at 15 at idle when she was running bad.

[neox.286]

LOL
I have a cylinder 4 misfire code as well!

would you happen to also have a code for system too rich?

[ND4MSP]

interesting, Ive had this same exact problem....however I replaced the maf with a buddies and it still didn't help it

sub'n...

What did it end up being?

[neox.286]

dunno, I should have use the present tense there lol (its late)

[ND4MSP]

No the shop that scanned it just said a misfire. The night my car took a shit my wideband was scary lean though. Like 16-17 at cruising and wouldn't move at all when the car would build boost.

[neox.286]

oh damn I just realized your in San Jose! haha, its a small world afterall...

[neox.286]

No the shop that scanned it just said a misfire. The night my car took a shit my wideband was scary lean though. Like 16-17 at cruising and wouldn't move at all when the car would build boost.

hmm, sounds like the EXACT set of problems Ive got
what mods do you have?

[ND4MSP]

dunno, I should have use the present tense there lol (its late)

No shit huh, when you posted I was thinking who the hell.... Oh wait, he's in the east bay.

[neox.286]

lol, side note, but you missed out on an awesome meet at putnam mazda earlier bro

you should check out www.moccforums.com, we get a lot of meets going on over there (thumb)
[/threadjack]

[ND4MSP]

hmm, sounds like the EXACT set of problems Ive got
what mods do you have?

Nothing really. MAM catted midpipe, drop in filter, atp wga that I think is on its way out because my car isn't building boost for shit at the moment. And a afc and CAI awaiting install when I sort the boost issues out first.

[ND4MSP]

lol, side note, but you missed out on an awesome meet at putnam mazda earlier bro

you should check out www.moccforums.com (http://www.moccforums.com), we get a lot of meets going on over there (thumb)
[/threadjack]

One of these days I'll get out to a meet. I'm kinda in family man mode at the moment. Bowling is my other thing I do, and I can't find time to practice anymore. So anytime left is car time. So when the speed's running like it should have out of the box, car time might= meet time.

[i like speed]

Standalone... Problem solved. lol jk. Sounds to me like a vaccume leak tho. You're supposed to be pulling at LEAST 20 psi vac at idle.

And with 16 afr I wouldn't drive the car until you get that shit fixed!!!

[ND4MSP]

Does a better tune increase spool time? But, yeah I need to atleast replace a couple lines. Like the ones that go into the tee for the bpv and wga, and the tee itself.

Forgot to add that I have a Forge BOV but that was the first thing I pulled when I first started having problems because it was easy to get to. But no change.

[i like speed]

Does a better tune increase spool time?

Was that just a random question or did you think that was why I suggested standalone? I was joking because with a standalone ems you can delete the maf and o2 sensors.

[ND4MSP]

It kinda thought that was why. I've always read about guys running aftermarket fuel control and how the car gained a lot of response, like if were speaking of a turbo'd car they would have response/spool. Maybe its placebo, or maybe its the tuning under boost. But deleting the maf and o2 sensors would be nice. My bad I didn't pick up on that. I'm just a rookie at this stuff.

[neox.286]

yea I think he was joking about the standalone, however if you are going for serious mods that should be on your list later (i.e., larger turbo, possibly built motor, etc...)....for now, this is definately not a tuning problem

I did notice that when I dropped in a set of wrx injectors (which flow much more) the idling issues went away entirely, however it came with a whole slew of other problems when trying to boost that was not a result of this core issue.....the point I have in bringing this up is that it seems to me that our cars are not getting enough fuel for some reason, if your symptoms are similar to mine at least

not sure how to fix the issue, just adding to possibilities of reasons why the issue is there

[ND4MSP]

Yea, I'm going to do the fix the possible vacuum/boost leak issue, then do the afc and cai and be done with it for a while. I've had her for 5 years and it literally has only run decent for 2. As far as bolting this and that on, it feels like I would be opening another can of worms everytime I put something new on the speed. I need to buy a beater some day.