10:1 AFR at idle all of a sudden...?

[shayandude]

all of a sudden toda yon the way to work once car was fully warmed up and the temp gauge was in the middle the afr starting dropping at the red light, and at idl the car was between 10:1- 10.7:1
it stayed this way and hasent changed. its a aem wideband sr20 blk top

[di-devol]

Checked for popped coupler, most likely a boost leak.

[Croustibat]

If you have a BOV, it is leaking. remove it.

[shayandude]

I checked all the couplers. Didn't look for vacuum leaks and yeah I got a hks bov . Think it's loose?

[fliprayzin240sx]

Pressurize the system, you got leak somewhere or you have a bad water temp sensor.

[OnTheChip]

Since it's going rich, I suspect either a faulty CLT (as suggested by flip), or possibly a leaky injector.

[shayandude]

Hey guys, thanks for the posts, I got home little ago, and with help of a bud, we pulled off the rail, and injectors aren't leaking, and looked good. Checked for vacum leaks and could not find anything. Of course we don't have a system, it was visual and feeling around. Is that sensor same as the CTS or different if so, I've already replaced that about a month ago. My buddy suggested changing out the plugs, they have around 400 miles on them so I don't know. Any other ideas? Oh from work to home which is around 10 miles it literally drank 1/4 tank. It's bad. Crusing, idling its all 10:1

[fliprayzin240sx]

Make a boost leak tester...



You can add small gauge on it too so you can see how much pressure you're pumping in there if you're not using a regulated air compressor. Also, you can use a wheel valve stem for the nipple. Lastly spray all your couplers with simple green and it should bubble up if you have a leak.

[Croustibat]

BOVs always leak with a lot of vacuum, typically at idle, unless they have a well made double piston system. It typically produce a 2 to 4 points AFR dip.

Mind you, 4-5 points means quite a serious leak. If that leak was happening all the time, the car would be having trouble and bogging down. If it only happens at idle though, there are great chances it is the BOV.

If you dont have a leak tester, you cant test, simple as that. You can try to loosen every clamps, nudge the couplers then retighten them. It usually works.

[PureRush]

Could be the fuel pressure regulator. Either the vacuum line or the fpr itself

[shayandude]

The fuel pressure regular was. Changed by Tay in Dallas along with few other. Things couple months ago. The bov looks like it was on tight and disint hear anything abnormal when revving it. Dealers do vacum leak tests? I wouldn't know where to go for that

[Danger_Dorn]

It could be a vacuum leak or it could be the MAF. 99% of the time with the AFR's its that damn maf. check it with a good one and do some vac hunting.

[shayandude]

so i figured,the cheapest thing i can start with is the plugs, sicne they are 10 bucks for all 4.
I use the bkr7e btw at .030 at 12 pounds t25
well i drove the car today from hoem to work about 20 min drive, and driving it was between 14.5-16.0 and wot at 10
idle when i got to works parking lot was 13.6-13.8 so im really really hoping it was the plugs, even though they were about 500 miles old.
ill keep everyone posted, planning on driving it a little more today after i get off.

[ultimateirving]

Originally Posted by shayandude

so i figured,the cheapest thing i can start with is the plugs, sicne they are 10 bucks for all 4.
I use the bkr7e btw at .030 at 12 pounds t25
well i drove the car today from hoem to work about 20 min drive, and driving it was between 14.5-16.0 and wot at 10
idle when i got to works parking lot was 13.6-13.8 so im really really hoping it was the plugs, even though they were about 500 miles old.
ill keep everyone posted, planning on driving it a little more today after i get off.

Did you use injector cleaner or similar on the other plugs before the afrs crapped out?

[Danger_Dorn]

The plugs very rarely have much to do with running rich. If your running rich you will black your plugs very soon so you need to address your fueling issue. I would seriously look at your MAF. The maf I just replaced would sometimes run ok and other times like complete crap. Just swap it out and see if you can pinpoint the problem.

Maybe give this a try? Idk anyone that has but it looks promising Air Flow Meter : Zen Cart!, The Art of E-commerce

[shayandude]

Didn't mess with plugs or apply anything to them.
I just Biut a used tested maf from a member recently