2g creeps to lean from 14.7 to all the way lean on idle and while cruising

newtodsm97gst · 07-22-2012, 01:31 AM

2g creeps to lean from 14.7 to all the way lean on idle and while cruising. mods are E316g, walbro 190 rewire, -6an line from pump to fuel rail, aftermarket fuel filter. mods are up to date on my profile. i search here but couldn't find it.
ok i did BLT, replace fpr with afpr and im still having the same problem. at starts the car runs fine on 14.7-15.2 afr, then it creeps up to lean like 19.6 to 20.0, my boost gauge reads from 21 vac to 18 vac when afr goes to lean and car runs like crap, it sounds like i'm running on 3 cylinder, could it be my injectors? and when I give it a gas it goes back to normal for 3 seconds and then back to creeping to lean. anyway my pressure on afpr is 43.5 without vac and 40 with. please help I'm getting fed up with this.

Any?

Spoolin92GSX · 07-28-2012, 01:16 AM

Sounds like it could be one or more injectors, more than likely clogged. Before you throw money for new ones, you might benefit from a Seafoam treatment - I would pull the wideband sensor first if you do the vacuum treatment too, all that carbon/smoke will more than likely eff up the sensor pretty quick.

Also, you can pull your spark plugs and "read" them; if one injector is clogged, that spark plug will be white/brown-ish from running lean and the other 3 will be black from running rich: computer trying to compensate for the lean condition.

Try those out and see how it goes

newtodsm97gst · 07-28-2012, 12:29 PM

will try that asap
check the spark plugs and all of them is like bownish. and i did a BLT again and found a leak on no. 3 fuel injector, would that cause my problem? i had a leak on 1 and 2 before and the leaning did not happen. i also hear hissing on the valve cover and it's coming from oil cap, would that cause the leaning too?

Spoolin92GSX · 07-28-2012, 06:23 PM

Quote:

Originally Posted by newtodsm97gst

will try that asap
check the spark plugs and all of them is like bownish. and i did a BLT again and found a leak on no. 3 fuel injector, would that cause my problem? i had a leak on 1 and 2 before and the leaning did not happen. i also hear hissing on the valve cover and it's coming from oil cap, would that cause the leaning too?

The brown confirms you are running lean. The leak on #3 is the "insulator" between the injector and head, you can get seal kits from a few different vendors. You hear the hissing during the boost leak test? That could be blow-by, I actually have issues with blt pressure getting into my crankcase.
Next step to diagnose the hissing would be a compression test and a leakdown test if necessary.

Since you're running lean in all cylinders, it's a global fuel issue as opposed to one injector being bad. Have you checked the condition of your ECU yet? It's possible something could have gone bad inside, and it's looking for the wrong mixture.

newtodsm97gst · 07-28-2012, 10:03 PM

Quote:

Originally Posted by Spoolin92GSX

The brown confirms you are running lean. The leak on #3 is the "insulator" between the injector and head, you can get seal kits from a few different vendors. You hear the hissing during the boost leak test? That could be blow-by, I actually have issues with blt pressure getting into my crankcase.
Next step to diagnose the hissing would be a compression test and a leakdown test if necessary.

Since you're running lean in all cylinders, it's a global fuel issue as opposed to one injector being bad. Have you checked the condition of your ECU yet? It's possible something could have gone bad inside, and it's looking for the wrong mixture.

ill check the ecu tomorrow, thanks for the help so far.

Spoolin92GSX · 07-29-2012, 02:51 AM

No problem man, I always try to help when I can.

WES_393 · 07-29-2012, 05:00 AM

To me it sounds like either a bad injector like stated before, or something going wrong with the front o2 sensor or ECU. One thing to try out: When the car starts to run lean and idle bad, pull the injector wires one by one. If you get to one injector wire and it does nothing to the state of the engine when you pull the wire, that's your bad injector. But I would also be interested in replacing the front o2 when you get the chance.

newtodsm97gst · 07-29-2012, 09:05 PM

Ok. replace the o-ring injectors top and bottom ( from Home Depot) lol.. anyway, so far its running good test drive it for about a couple of miles and looks to be in good running condition.. I check the ECU and it looks great, i didn't see anything wrong with it. the O2 sensor in the front is barely new from mtx-l innovate wideband so, i don't think that was the problem, but to be safe i re calibrate it. so far its running good. again thanks alot for the help specially to Spoolin92GSX.

Spoolin92GSX · 07-30-2012, 12:02 AM

Quote:

Originally Posted by newtodsm97gst

Ok. replace the o-ring injectors top and bottom ( from Home Depot) lol.. anyway, so far its running good test drive it for about a couple of miles and looks to be in good running condition.. I check the ECU and it looks great, i didn't see anything wrong with it. the O2 sensor in the front is barely new from mtx-l innovate wideband so, i don't think that was the problem, but to be safe i re calibrate it. so far its running good. again thanks alot for the help specially to Spoolin92GSX.

Good to hear that did the trick for you!