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Changing out parts without a confirmed diagnosis just adds to the variables of what could be the real issue. This is the case when using aftermarket parts, in particular electronic ones.
Reading data
as mentioned above, bring engine to operating temp. Now, using Blue Driver, look for fuel status (?) as one of the picks. It needs to read CLOSED LOOP in live data . If it reads OPEN LOOP, that needs to be diagnosed first.
You mentioned. - For the past 8-9 months, I have had a p0171 code (Bank 1 too lean)
Making an educated guess, during the 8-9 months, how often did your check engine light BLINK on/off.
example - check engine light basically stayed on during this entire period (8 months) and 25% of that, it was blinking
Reading data
as mentioned above, bring engine to operating temp. Now, using Blue Driver, look for fuel status (?) as one of the picks. It needs to read CLOSED LOOP in live data . If it reads OPEN LOOP, that needs to be diagnosed first.
You mentioned. - For the past 8-9 months, I have had a p0171 code (Bank 1 too lean)
Making an educated guess, during the 8-9 months, how often did your check engine light BLINK on/off.
example - check engine light basically stayed on during this entire period (8 months) and 25% of that, it was blinking
Throughout the 8-9 months, The check engine light was on the entire time and would only start blinking as I'm accelerating from idle or sometimes when I'm going up a steep hill. While the car was in idle or cruising, the check engine light would not blink but would be on.
After the fuel pump and filter replacement today, It started to flash the check engine light while accelerating, then turn off completely. I drove the car for only 10 minutes after the replacement so I don't know if that will be permanent, but it is new I believe.
Originally Posted by Margate330
Hi friend, this is hard to see what exactly the fuel trims are at idle because it's in live data mode.
Need to know the fuel trims at idle.
As maxsteel requested, can we see the fuel trims numbers at idle, plus car warmed up. Need to see where those numbers settle at.
I'm sorry I can't make heads or rails of this because it's in live graphing mode.
WHAT are the fuel trims at idle, please, engine warmed up and let the fuel trims settle and post it up.
Yes please, g/cms/s.
Should be 3.0g at idle, engine warmed up
I will get those numbers for you tomorrow, but the car was mostly warmed up and it sat in idle at around 6 g/s in the last graph i posted.
Also, the fuel trims are acting differently from when the car is idling in drive and when it's idling in park, I will post both sets tomorrow. I will also get the numbers for cruise controlled at 45 mph with the g/s.
Originally Posted by Margate330
For sure!
>> For OP
What I think we are all trying to see is whether or not its a vacuum leak or something else.
To be honest, the fuel trims are horrible for all tests posted so far, so there's something going on.
Comparing the fuel trims to a baseline at idle as@maxSteel suggested let's us see if fuel trims get better or worse depending on engine load and rpm.
If fuel trims are worse(and higher) at higher sustained rpms than at idle, it's likely NOT a vacuum leak(at least in higher rpms & engine load
Ps, could be a combination of things so need to rule stuff out.
The fuel pump and filter that I replaced today seems to have been part of the problem, not a massive part but noticeably different from beforehand.
I did a crude vacuum leak test with a smoke machine at the air intake just past where the MAF sensor would be, about 2 months ago.
I did not see anything besides some smoke coming out of one of the coil packs on cylinder 2, but I promptly fixed that.
The smoke machine was cheap so I might've missed something though.
Flashing CEL usually means misfire. That should generate one or two codes.
Salim
Correct. 8 months check engine light, flashing on occasion - raw fuel in misfired cylinder(s), CAT can't burn off.....
Monitors not run during this period due to check engine light (future P0420/430??)
Down stream O/2 sensor voltage will show CAT performance
Correct. 8 months check engine light, flashing on occasion - raw fuel in misfired cylinder(s), CAT can't burn off.....
Monitors not run during this period due to check engine light (future P0420/430??)
Down stream O/2 sensor voltage will show CAT performance
Only suggestion I have is clear codes, and try to fix misfire before checking/working on anything else. If bank related check OCV. If individual cylinder check compression. Oh please make sure you have OEM plugs & coils. Deduce plug or ignition coil issues by swapping combination.
Only suggestion I have is clear codes, and try to fix misfire before checking/working on anything else. If bank related check OCV. If individual cylinder check compression. Oh please make sure you have OEM plugs & coils. Deduce plug or ignition coil issues by swapping combination.
Salim
Yea right now the only codes that are appearing are cylinder 3, 5, and 6 misfire, multiple cylinder misfire, and bank 1 too lean, they all come on simultaneously and every time. Cylinder 3 is somewhat new though only appearing about 2 months ago, so I might look into swapping coils and plugs for that one. But I can swap cylinder 6 plug and coil into 4 since its up front and see if the problem moves too.
Can we see one screenshot of fuel trims just at idle so we can see the actual idle numbers? Idle only
>> Engine fully warmed up at idle.
Then another separate screen shot of only cruising at 45 mph with cruise control on? cruising only
I made a few videos of the car idling in drive and park of about 20 seconds long with numbers instead of graphs. I made videos because it fluctuates quite a bit in idle. (The 20 second videos automatically turned into YouTube shorts so sorry about that)
(Idling in Park)
I also made a 10 minute long video of a drive home and included a 40 second bit where I was cruise controlled at 45 mph. The car is in limp mode so the RPM is quite high.
(10 minute video) The Cruise Control is from 1:42 to 2:18 in the video.
Also I will get a video later today, but whenever the car starts from a cold start, the misfires are extremely bad, to where they are very loud and constant and shake the car a little bit, and once the car warms up, they almost completely disappear. Almost to where you wouldn't feel it unless you are waiting for it. (This is all in idle, no driving)
(Edit: Yes, The car is completely warmed up for all 3 videos, the 10 minute drive one starts with the car warmed up)
So I finally got some time to tear down my engine down to the fuel rail and I noticed that my fuel pressure damper does not look the same as the one from pictures online or my OEM one on the rail.
Originally Posted by Obscurations
This is what my fuel pressure damper looks like with a boroscope camera up close. This is what it looks like online
Neither store gave it a part number and that Lexus link is the only thing that kind of looks like it, so I don't know if this will work for what I need. but for now, it looks like it will fit on the fuel rail.
But it was either pay double for the part from manufacturer what a parts store will cost, or buy it used / refurbished OEM from eBay when there is no guarantee it works as original.
(And I can't afford manufacturer prices.)
Also what I'm scared about is the open ended bolt on the OEM one on my rail, is not budging no matter what I do after spraying it with WD - 40 a few times and letting it soak for about 30 minutes and that bolt is a slightly larger size than my new part.
The parts are different and when an aftermarket is produced they are manufactured to match the published spec. This gives the aftermarket manufacturer to use material and manufacturing techniques to cut down production costs.
It might be too old for most of the users when PC manufacturers used to make IBM "compatible" PC. [emphasis within quotes].
Technical reasons for the screw is to allow adjustment to the needed pressure.
When I do DIY, I always get OEM from dealer, specially when I am trying to solve a problem. It just takes lots of unknowns out of the picture.
Yea at this point I might as well buy the part from lexus for $110 instead of the parts store for $60. I bought the part like 2 weeks ago and lost the metal snap rings and I don't know if its a good idea to use the old ones.
05-21-24, 09:03 PM
