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Engine Jerking Problem
Posted: Sat Mar 28, 2009 9:14
by zoomzoom6
So this morning I let my car warm up like usual. When I proceeded to drive to work the car jerks and/or bounces like the fuel injectors aren't firing right. The car idles fine and I can rev it in neutral or in gear with the clutch pressed in and it's fine. It only jerks or bounces when I'm accelerating at a moderate rate. If I go wide open throttle it's hit or miss if it does it or not.
When I left work to come home it started sputtering after it was started as it warmed up. I think it may be a stuck throttle body or something of that sort. I can pretty much rule out injectors, fuel pump and stuff of that nature. I'm wondering if it may be a sensor as well, maybe the throttle position sensor? At this point I'm just annoyed at the car. It's still driveable so I'm not too irritated, just annoyed. Anybody have/had this problem and know how to fix it? Any advice before I take it into Burt Mazda and have them look at it?
Thanks in advance,
John
Posted: Sun Mar 29, 2009 9:14
by wyosaint
it may just be a bad batch of gas from the last time you got fuel. get like seafoam on your next fill up, let it run half a tank or so and fill up again, that should help.
Posted: Sun Mar 29, 2009 9:14
by tsx_guy
your maf sensor my be dirty from the rain/snow and a CAI? bad gas is a good guess also.
Posted: Sun Mar 29, 2009 9:14
by zoomzoom6
I was wondering if it was a bad batch of gas. I put some condensation eliminator in the tank to see if that was the issue. This problem happened the morning after it snowed really hard, so the guess of the MAF sensor being dirty could be the culprit. Last night my tank was about a 1/4 full so I filled it up completely from a Conoco (Shell was my last tank) to see if the gas was the problem. Today it was still doing it but not as bad. I'm going to take it to Burt Mazda tomorrow and have Dave look at it (perk of living with his son haha). It hasn't thrown a check engine light at all which tells me that it must not be anything crucial, but again that isn't always the case. I'll see what they have to say, hopefully it's just the MAF sensor seeing as to I have an AEM CAI which is in need of a desperate filter change. Thanks for the info guys, much appreciated.
Posted: Mon Mar 30, 2009 9:14
by AIM WO4
Let us know what the diag is. I have had bad gas do that in my turbo'd Saabs. I just added octane boost to get rid of it. And I don't get gas at the base any more.
Posted: Mon Mar 30, 2009 9:14
by tsx_guy
I have sworn by shell gas, I get 1-2 mpg more over the conoco stuff.
I looked at my MAF last night and noticed it was very dirty. My filter is still pretty darn clean so I am trying to figure out how this happened. No issues with performance or what not, but I plan to clean the sensor in the next few days. Good luck getting your issue resolved John.
Posted: Tue Mar 31, 2009 9:14
by zoomzoom6
I went and dropped it off at Burt Mazda yesterday afternoon. Once I know what the diagnosis is I'll post on here. May give some insight for people that may have this problem in the future.
Posted: Tue Mar 31, 2009 9:14
by tsx_guy
curious to see what they find out.
Posted: Wed Apr 01, 2009 9:14
by zoomzoom6
Got the call today and it's a bad air/fuel sensor. Of course the problem occured 250 or so miles after my warranty expired. So the sensor itself is roughly $205. But it has to be fixed so I guess it's the price that has to be paid.
Posted: Wed Apr 01, 2009 9:14
by RX-7 Chris
isn't that the way it always works. glad it is getting fixed.
Posted: Wed Apr 01, 2009 9:14
by tsx_guy
bad air fuel sensor, do you mean the MAF sensor?
Posted: Wed Apr 01, 2009 9:14
by zoomzoom6
6i_guy wrote:bad air fuel sensor, do you mean the MAF sensor?
MAF or "Mass Air Flow" sensor is usually located on the intake. The A/F ratio sensor is used on newer cars in unison with your secondary O2 sensor which is located on the exhaust part of the car. They're two seperate sensors.
Posted: Thu Apr 02, 2009 9:14
by tsx_guy
zoomzoom6 wrote:MAF or "Mass Air Flow" sensor is usually located on the intake. The A/F ratio sensor is used on newer cars in unison with your secondary O2 sensor which is located on the exhaust part of the car. They're two seperate sensors.
thanks for clearing that up John. The car running better now?
Posted: Thu Apr 02, 2009 9:14
by zoomzoom6
6i_guy wrote:thanks for clearing that up John. The car running better now?
Haven't gotten the car back yet, hopefully later this afternoon. Dave unplugged the air/fuel sensor from my car and drove it around without one and it ran fine, but didn't throw a CEL which we both thought was weird. The new part is scheduled to arrive sometime today. He also cleaned my MAF sensor which was apparently realllllly dirty. I hate DryFlow filters that AEM has. I'm going to swap it out with a K&N oiled one I think. So if all goes to plan I'll be able to pick it up later today and be zoom-zooming around!

Posted: Thu Apr 02, 2009 9:14
by kingtut
zoomzoom6 wrote:I'm going to swap it out with a K&N oiled one I think.
Don't those oiled K&N's tend to mess with the MAF's, or did I hear wrong?