StkmltS

My fuel pressure is consistently lower than spec by an inconsistent amount (psi). I replaced the fuel pump attempting to fix the pressure issue... hoping that's what's causing my misses. The coil packs are tight. If there was a connection issue somewhere, as many times as I've taken them off I imagine I'd have accidentally have wiggled them on correctly at least once. This weekend I drove about 260 miles to/from a camping event (Red River Gorge, Ky), with 3 passengers and all of our gear, and got 23.10 mpg. Most of that was cruising at 80-85 mph.

9,500 miles on the rebuild and I'm extremely happy to report that all is well. Oil consumption is minimal. I'll know exactly how much it's using in a week or two at my next oil change. The minor oil leak appears to have stopped on it's own. It doesn't leave spots on the ground anymore so I guess it just stopped. On my last tank of gas I got 17.7286781 mpg. This summer there's major construction both ways on my commute, and I'm surprised my mileage is as high as it is. Creeping along at 5mph for 20 minutes and then boosting the rest of the way home at 80-90mph for 10 minutes hasn't hurt as bad as I was expecting. A few weeks ago I replaced my OEM fuel pump with a DW65c, a new sock, and a new filter, and that didn't solve my misfire issue. I also glued the cracked part of the pump housing back together, and since then I haven't smelled gas in the cabin or seen any fuel on the ground. My on-board-computer-thingy consistently calculates about 0.6 mpg lower than actual. My injectors are stock, and it was like that before my new fuel pump, so I wonder if somehow that's connected to whatever is causing my misfire.

Can you post a picture of your DIY cam pulley lock tool? I'm in the middle of helping a friend replace his motor and when it's time to put the TB back on I'd LOVE to try something different than what I've used in the past.

If it was something easier I'd say take it all off and put threadlocker on the bolts, but the TB is too much of a pain in the butt. Can we assume you used a torque wrench? In a few hundred/thousand miles take off the belt covers and re-torque the pulley bolts. If they're all still torqued down and don't need tightened then I'd say you're good to go as-is.

So a new fuel pump and filter didn't stop the misfiring. My cracked housing is a problem, but it's cracked in an area that I don't think affects fuel pressure (see pics). I fixed the crack with some super-super-glue + powdered plastic, but long-term my housing will need replaced. Pics aren't uploading from my work computer so I'll try to upload them later.

USPS says my new (used) fuel pump and housing are waiting for me at home. I'll swap it in later tonight if I have time after the kids are in bed. *Update* Didn't happen last night. I didn't buy what I thought I bought so I'm back to fixing my housing and putting in a new (used) pump.

The problem started when all four injectors were still OEM that came with the car. After I bought one used injector on ebay the problem continued. I was still on the 100% stock tune when the problem started, so I doubt the problem is in the tune. Which injector tables are you referring to? My AFR (per LVs) are almost always well within the ±5% that people say is acceptable. As of a couple days ago they were -2.60/0.60/4.60/-0.80. In the past, increasing the fuel (lower target AFR) actually reduced the quantity and frequency of misses. So far that's the only thing I've been able to do that's affected the misfiring. I posted a few charts many pages back... somewhere. Why do you say I'm getting excess fuel in #2? I'm inclined to think that I'm getting not enough fuel (low fuel pressure, leaky housing, AFR slightly too lean, observed MPG consistently 1-2 mpg better than the displayed MPG).

Bummer

^ nothing wrong with that, although I haven't seen the file. Maybe even add a few alignment tabs here-and-there to make assembly easier.

I love me some Kentucky rice!

My miss is not being caused by the plugs, coil packs, or injectors. There may be a problem with the connectors or the wiring, but the devices themselves are not the root cause. Until recently I was careful to only make one change at a time, so that if the miss changed I'd know exactly why. My spirit has been broken, and now I'm totally satisfied just by blindly trying handfuls of fixes at the same time and praying for a change... any change. Here's an short(ened) list of things that haven't caused a measurable change: Original intake manifold o-ring gaskets New intake manifold o-ring gaskets Old spark plugs Old spark plugs re-gapped Old spark plugs w/ swapped positions New spark plugs New spark plugs w/swapped positions Original coil packs Original coil packs w/ swapped positions New coil packs Original injectors Original injectors w/ new o-rings Original injectors ultrasonic cleaned Original injectors w/ swapped positions New (used) injector in cyl 2 New silicone vacuum hose Original TGV gaskets New TGV gaskets Rebuilt motor FPR ref line relocated to the BPV

Cyl 2 is where I see the most misses (highest roughness count), but cyl 3 also regularly misses. The dark brown spot on plug 2 is a stain from something. Maybe I got a drop of oil on it when I installed it during the rebuild. There's no missing material. Up close and in-person, plugs 1, 3, and 4 look almost identical to each other. The only obvious difference between any of the plugs is the color of the ceramic on plug 2. It was very slightly off-white (and has a big dark brown spot), while the ceramic on the rest of the plugs was a nice crisp-white.

No apparent change to the frequecy of misses at idle. Sent from inner space.

Cylinder 2 has a little bit of fluid pooled at the bottom. Cylinders 1, 3, & 4 are dry, and look as dirty as expected after 8k+ miles. I fished a paper towel around inside cyl #2, and the liquid has the distinct smell of fuel, but the color of oil. Plug #2 came out wet (not enough to drip) and smelled like fuel. So I'm saying the fluid in #2 is gasoline.

1 - 2 - 3 - 4 (left to right) New positions: 1 (was 1)- 2 (was 4) - 3 (was 3) - 4 (was 2) I also put in four new non-OEM coil packs.

Does pressure inside the tank (or the lack of) somehow effect fuel pressure at the injectors?

After my drive home today fuel pressure @ idle was a steady 26/27 psi. I dunno if it's causing my problem or not, but it seems out of spec enough to justify spending a little money on a new/used pump. Sent from inner space.

What does losing a gear feel like? Since the mood in here has already been set to "negative"... My friend's turbo blew a few days ago and now he's facing the evil YNANSB monster. Is there anything special I need to know about rebuilding a post-facelift 4th gen?

How are you logging? (BtSsm, Cobb AP, or laptop) Pop the ol' hood and follow the wires coming out of the sensor. If you can tell us where they go we can probably help you figure out where to look for the problem.

pretty

The rebuild has a little over 8k miles on it and all is well. Tuning is fun, boost is fun, and 18 mpg is not fun. The car has been surprisingly uneventful lately. Even the oil leak seems to have stopped. Oil consumption is a thing, but after 2k miles on this oil change the level just now dropped below the full hole on the dipstick. I check the oil every time I get gas... I'm pretty sure that's going to be a lifelong habit. I keep BtSsm open 99% of the time, and I never (ever?) see knock events in situations that would be concerning. I do occasionally see knock between shifts, but I think that could be related to the exhaust hanger near the transmission that my exhaust isn't hanging from anymore. I bent the hanger for a reason I can't remember now, and I never bent it back. I know I should fix it, but I've really been enjoying my time spent anywhere other than under the car. It looks like I may have found my gas leak. I drove around for a few days earlier this week with my rear bench out and the tank access cover off. WARNING: Only drive with that cover off for a few days if you really want to get paranoid about your car. Man alive, you can hear every bump, squeak, and groan the car makes. And you freak out whenever you're next to a semi on the highway because of all the scary noises you think are coming from your car because you don't fully trust the guy who rebuilt the motor. Anyways... fuel is definitely leaking out from the top of the tank. The gasket is relatively new so maybe there's something else going on. It looks like fuel is either leaking out past (in spite of) the gasket, or it's coming out of the top around the the little plastic do-hickey that the fuel line connects to (the bottom fuel line in the pic). In my misfire thread I've been exploring the relationship between my lower-than-spec fuel pressure and my misfires, so dealing with my fuel leak could have something to do with the misfires. I like throwing two stones at one bird, so solving the fuel leak is at the top of my list of things to do when my wife isn't home.

I have the PLX and I've never had any issues with it. How is yours wired? Mine is sending the signal through a deleted TGV sensor.

Since I started playing around with tuning I've gained so much more respect for the phrase "like a finely tuned machine". Tuning is awesome. Making useful changes to a car (for free) AND learning.

I didn't realize the target AFR table (Primary Open Loop Fueling) was that less-than helpful. That would explain why I haven't quite gotten the results I was shooting for by playing around with that table. So when I want to make a small group of cells slightly richer in order to address FKC events, or to make the CL/OL transition smoother like you said, I should increase the appropriate columns in the MAF scaling table... and then do what with the primary open loop fueling table? Do I also change those few cells to the end result I'm hoping for so that my fuel trims stay under control? If I'm understanding correctly that would make sense (not being sarcastic). At the bottom of the table in RomRaider it even says "Estimated Air/Fuel Ratio"... geesh, I wish I would have noticed that before now. When you mentioned the disconnect between desired and actual (12 to get 14.7) were you talking about the value in the primary open loop fueling table?

Why are you adjusting the MAF scaling instead of target AFR? I'm still a tuning noob so maybe I didn't understand you correctly.