Rich on one side - P2196 (passenger, bank 1)

Hey everyone. Thanks for all the help in my other thread (cam position sensor problems), but now I'm experiencing another issue, so I'm starting a new thread.

I had a spun rod bearing back in 2013 and long story short... just recently got it all back together. I was unmotivated, had no time, and needed a break from it. MMR hooked me up and repaired the block, and I didn't get it back in the car until sometime last year. When it was all back together, I had tons of little issues that have been mostly resolved. The biggest one may not have been an issue, per se, but had to do with the types of lockouts I was using (two-piece set, from Rich Groh). I have no idea where those put the cam phaser advance, but I kept getting CPS errors. I ended up popping those out and putting the more typical Livernois ones in (locked out fully advanced).

Since starting the car back up, the passenger side (bank 1) has been running very rich. I have two widebands... one for each side, which has helped, but I still can't figure it out. On bank 2, the wideband idles at ~14.6, where it should. Bank 1 idles at anywhere from high 11s to low 13s... but usually at 12.5.

Here is what I've done so far to troubleshoot:

- Checked far and wide for vacuum and exhaust leaks. None found.
- Compression check. All cylinders within 1-2psi.
- Installed new O2s. No change.
- Checked for swapped O2s. Just as they should be.
- Checked for pinched wiring. None found. No extensions in use.
- Checked for ground outs on O2 wiring. None found.
- Tested injectors with 12v. Each clicked opened/closed cleanly.
- Inspected spark plugs. All look roughly the same. (pics below)
- Checked all intake manifold and injector o-rings with carb cleaner
- Datalogged/pulled CELs. Only P2196 found (logs below)

I'm at my wits end. It'll sometimes start and idle, but it's rare. Usually, it needs a lot of assistance (pedal to the floor), then needs 3000-4000 RPM for a good minute or so before it'll clean up. Blipping the throttle will make it dip down to 500rpm or so, and then it will (usually) recover. If I can get it to start and idle on its own, it'll run until I shut off the key... but it'll always be at ~12.5 AFR on the passenger side, and normal on the driver side.

I've taken some datalogs, and the only thing I can see weird is one of the O2 voltages seems to jump around a bit.

Not sure where to go from here. JP06GT had a similar issue, but didn't post the resolution. I PM'd him. Any ideas would be greatly appreciated.

Here's a quick rundown of my setup, though most of you are probably already familiar:

- 5.4L 3v MMR 1000 shortblock
- Rich Groh (RGR) heads and custom turbo cams
- Livernois lockouts / VCT removed (3v V10 block plates)
- JPC 3v Intake, customized for 5.4L
- GT500 throttle body
- TurboHP kit w/61mm billet turbos
- Lethal Performance triple 255lph fuel pump kit (return style)
- Bosch 160lb fuel injectors
- Autolite HT0 spark plugs

Here's a log from yesterday with Motorocraft O2 sensors:
http://www.cabuzzi.net/website/images/car/misc/P2196/P2196_Idle_Motorcraft.zip

Here's a log from today with NTK O2 sensors:
http://www.cabuzzi.net/website/images/car/misc/P2196/P2196_Idle_NTK.zip

Here's a pic of the spark plugs:


Here's a video of the car running (sounds pretty normal):

first thing i would do is inspect the wiring for the o2 sensor and make sure it didnt get pinched anywhere.

irishpwr46 said:

first thing i would do is inspect the wiring for the o2 sensor and make sure it didnt get pinched anywhere.

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Yeah.... I did that. Visually, and by checking to make sure by unplugging the harness at the PCM and checking each of the signal wires to ground.

You could swap injectors side to side and see if it follows. How far off are the fuel trims?

BruceH said:

You could swap injectors side to side and see if it follows. How far off are the fuel trims?

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Good idea on the fuel injectors. I didn't think of that.

I just looked at the fuel trims. What's weird, is that they always match. The log I attached from yesterday is almost 12 minutes long, but the STFTs and LTFTs never diverge. They're always exactly the same.

Spark also looks strange. I'm used to seeing the advance in the 30s at idle. In the logs from yesterday and today, advance was mostly in the single digits, and never higher than 20*.

I'm fairly certain if the ECU thinks theres a problem with an oxygen sensor, it ignores the side it thinks is malfunctioning. That could explain the fuel trims always matching. I had a sensor go bad a while back and the computer just ignored that sensor and used the other side for both banks.

Towelie said:

I'm fairly certain if the ECU thinks theres a problem with an oxygen sensor, it ignores the side it thinks is malfunctioning. That could explain the fuel trims always matching. I had a sensor go bad a while back and the computer just ignored that sensor and used the other side for both banks.

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You are correct. Lito explained that to me earlier.

I have a little update (hopefully Lito sees this, as I can't email him right now).

The injector service place called me back today. They were nice enough to test the injectors both before, and after cleaning. Overall flow rate went up, as you would expect after a cleaning, but it was uniform. There was no one injector that flowed differently than the other, which effectively rules them out.

However, I keep coming back to a very similar problem I had in the past... with this particular engine, same heads, same cams. That was very similar, though much, much worse. After testing everything, it turned out my cams were off. Whether it was me, or the crank gear jumping the chain on the first startup, I dunno. It was on an engine that had not yet been started, so there was no oil in the passageways. All I know is that it was exactly two teeth off. I was able to verify this with a compression test, which was 95psi on each side. The overall effect was roughly the same (fuel trims that were uneven and never settled out).

That sounds incredibly low, but the most I ever see on a properly timed engine is 135psi, and that was on a stock 3v 5.4L. Unfortunately, I don't remember what the compression test after fixing it was. For all I know, it may have been lower than the 135 I saw on the stock engine. I do know the cams have an 112 ICL and the previous cam phaser lockouts were the two-piece, 10* retarded lockouts.

Since then, I've put the cam phasers back together with the single-piece, 0* lockouts, which effectively advances the cams 10* from what they were with the two-piece ones. I now have a net compression of around 120 on each cylinder. What I don't know... is if that is normal for my altitude, cams (I can provide more info on the cams when I get home), and cam lockouts. Remember my altitude, which is 7200ft. Using an air pressure calculator, my pressure at altitude is 11.26psi (vs 14.7psi at sea level). That works out to about 76% normal air pressure. If a stock Mustang makes around 170psi on compression test (my guess), the same engine should make at least 130psi on at altitude (which is in line with my stock ~135ish number).

Could my cams and the lockouts knock that down to 120psi, assuming my CR is stock.... or do I have another crank-jumped-chain issue?

compression is same on both banks? Seems unlikely you'd have jumped timing the same way on both banks.

I don't think you can math out static compression w.r.t. pressure at sea level.

Calculating compression pressure is actually pretty easy. I've always used the following formula, which is kind of a hack/shortcut, but usually works out pretty damn close. This is with the typical cam profile you see in stock cars, however... and does not take into account the type/position of the cam, which is where I'm ultimately unsure:

Compression pressure = ((air pressure x CR) + air pressure + CR)


So for a Mustang GT 3v with a 9.8:1 CR, at sea level, the formula would look like this:

My earlier estimate of 170psi was pretty close.


The last time I did a compression test on the stock 3v 5.4L from an 05 F150 was back in 2012. I recorded an average of ~135psi per cylinder.

Using the above "cheater" formula (the actual formula is much, much more complex (see attachment), is as follows:

Again... pretty close.


According to MMR, my current CR is 9.95:1. That, at my current elevation, would look like:

Nearly the exact same cylinder pressure. Pretty crazy that the slight bump in CR and the slight change in altitude (400-500ft higher) came to the same pressure by the hundredths.

At any rate, this does not, take into account the cam profile or mechanical retard/advance. That is what has me coming back to the question: Is 120psi normal for my lockouts and cam profile?

Here is some more info on my cams:


...and of course, my cams are now at 0* vs 10*. I'm guessing Rich factored that in when speccing out those cams.

You could plot valve events on paper or watch them on the motor. To me it looks like your cams were designed to bleed a little boost off due to the 116 lsa. Add to that the long durations and I'd guess that some compression is being bled off. It's just a guess until it's plotted. It's also a guess from someone who only has basic knowledge when it comes to the whole "why/what for" aspect.

I do think that plotting the valve events on paper will show you if an exhaust valve is being held open enough to bleed compression during the compression stroke.

BruceH said:

You could plot valve events on paper or watch them on the motor. To me it looks like your cams were designed to bleed a little boost off due to the 116 lsa. Add to that the long durations and I'd guess that some compression is being bled off. It's just a guess until it's plotted. It's also a guess from someone who only has basic knowledge when it comes to the whole "why/what for" aspect.

I do think that plotting the valve events on paper will show you if an exhaust valve is being held open enough to bleed compression during the compression stroke.

Click to expand...

That would be something I know nothing about, but I'm willing to learn. I leave Sunday morning for yet more work travel, but I should have some time to read up on it and see if I can figure it out.

My gut tells me that 120psi is low... even for my altitude, but it sounds like the change in the cam phasers could theoretically account for it.

Flapjack said:

That would be something I know nothing about, but I'm willing to learn. I leave Sunday morning for yet more work travel, but I should have some time to read up on it and see if I can figure it out.

My gut tells me that 120psi is low... even for my altitude, but it sounds like the change in the cam phasers could theoretically account for it.

Click to expand...

One of the nice things about a turbo setup is that you can dial in more cylinder pressure at any time without much hassle. Provided that everything is mechanically working as it should low cylinder pressure is an easy fix for you.

BruceH said:

One of the nice things about a turbo setup is that you can dial in more cylinder pressure at any time without much hassle. Provided that everything is mechanically working as it should low cylinder pressure is an easy fix for you.

Click to expand...

You mean via boost controller?

By the way, here's report. I was a dumbass and didn't separate/label the injectors... but it looks like there actually may have been some issues at low-rpm. There were four injectors that clocked 12ml @ 6ms-6000rpm. The rest were 16-17ml for the same test. That's a 25-30% difference. If, by chance, 3-4 of those that flowed 12ml were on the driver's side of the engine, that could explain the crappy/rich idle.

Here's a PDF of the before/after report:
http://cabuzzi.net/website/images/car/turbo/fuel/injector_test.pdf

**UPDATE**

After working with Lito, the various rich CELs are likely a side effect of a COP problem. He was looking at the STFTs and saw a telltale reading "stuck" on 1.0499999... which indicates one or more COPs have been shut down to prevent damage to the catalytic converter. What I don't know is if it shuts down fuel as well. My guess is "yes", as while driving, the car is basically at full lean on that side of the engine (per the driver's side AEM wideband).

When I first got the engine back together, I had a P0358 (COP problem, cylinder 8). I have a whole extra set of COPs, so I grabbed one and swapped it. I didn't see the code again. That was weeks before I actually drove it.

Since I changed the cam lockouts from 20* to 0*, the car was running rich. Lito sent me a revised tune which cleaned up the passenger side, but the driver's side was still very lean. I will occasionally get a P0357 (cylinder #8), but not always. However, that side is always lean. I'm not sure what algorithm the PCM uses to set that code, but it may/may not be helpful in troubleshooting.

I've tried moving the COP around, but the code stays P0357. I went ahead and changed all the COPs, but the P0357 code stays on... pretty reliably now. I even changed the plugs (swapped #6 and #7), but the code stays on cylinder 7.

Since there seems to be absolutely zero fuel/spark happening on that side of the engine, I can't really tell if it's one, some, or all COPs. I'm also very curious to see what types of things could cause the COP errors to set. I've checked wiring, but all seems good. I haven't stripped off the sheathing/elec tape, but that may end up being my next step.

Could a bad fuse cause the problem? I did (stupidly, I might add) attempt to ground the COP common wire to the front of the engine without the little square resistor. That blew 3-4 fuses, which I replaced. Maybe something else cooked (eg: relay)?
where I grounded the COP

Bump? Anyone have COP problems that were not resolved with swapping them, or changing spark plugs?

This has me wondering about my startup issues and those resistors not grounding well enough. I have another thread and me and Lito are working on it too right now. It's like my drivers side doesn't fire but passengers does


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Wraith said:

This has me wondering about my startup issues and those resistors not grounding well enough. I have another thread and me and Lito are working on it too right now. It's like my drivers side doesn't fire but passengers does

Click to expand...

That is basically exactly what is happening. It's like the whole driver's side isn't firing.

I did check the resistor, and it seems the same as it's always been. Not sure how to check, if they're working. I guess I will pull off the new one I got for the passenger's side and measure resistance across that, then compare with the driver's side.

I'm headed down the path of vaccum leak and doing compression and leak down now. I don't really see anyway this could be tuning issue. The stock intake has 3 vaccum ports(so I have seen) and I'm using the biggest near the TB for my vaccum block and the other two are capped. Lito advised if I had a leak big enough to make drivers bank do what we are seeing the car would rev up on its own which doesn't happen.

It won't idle long enough to listen and test for a leak likewise not so keen to spray fluid on a new pretty motor lol.

If the two sides were not so different in how they looked on the plugs I wouldn't think along these lines. Perhaps I don't have fire at all guess I will check that next.

GRRRRR

Well, I've ruled out vacuum and exhaust leaks at this point. I have an ungodly amount of vacuum lines between the boost controller, twin turbos, wastegates, blah blah. I never just pop the hoses on the fittings... I always use tiny hose clamps for them. In addition, I've gone over every inch of hose and sprayed carb cleaner all over. Nothing. Not even the tinyest RPM change.

I haven't had a whole lot of time to troubleshoot, but I should have more time this weekend.