shifted to a new thread as topic has changed completely...

now I'm really confused...

Hooked up the fuel line pressure gauge..... ran it at idle and unhooked the vacuum line, pressure went from 40psi to 45psi.... hooked it up and ran it on the road, kinda bounced around from 38-41psi at low rpms/loads... got it up to speed above the cam and it maintained 41psi steady.... WOT ran it twice, experienced the same power loss I've felt before, fuel pressure maintained 41-42psi.... at near-idle speeds on the deceleration it dropped as low as 36psi, but that's normal I take it. Shut the vehicle down, pressure instantly dropped to 35psi from 40, but stayed there, therefore I assume its not leaking through the injectors.

So now I'm really confused as to what the problem is. I know I have spark, just changed the opti, runs fine at high RPM's as long as throttle isn't wide open, runs fine across the RPM power-band. just at WOT from 5000+ (and steadily getting worse (more loss of power sooner, this problem started at 5500 2 months ago).
Datalogs show at this speed first the right o2 sensor drops from 900mV to 70mV, and immediately after the left now (before it was just the right), which would be indicative of fuel starvation since the feeder line comes in on the left side.
I moved all my injectors from the right to the left side and vice versa to emlinate the idea that the injectors were bad....and I believe I just eliminated the idea that it was the pressure regulator.....

So given this information I'm 90% sure I have a fuel delivery problem.....but according to all the testing I've eliminated the fuel pump, fuel filter, fuel pressure regualtor, and fuel injectors...

Any idea's?

Here's the latest datamasters....

http://www.savefile.com/files/642389

http://www.savefile.com/files/642393

and yes, the MAF code has been thrown, I just haven't reset it. It got thrown when I fired up the car after the opti install to ensure it was running before I put everything back together.

 

No one has some input? Or testing idea's?

This could be a number of problems, and I can take a guess that its the injectors, maybe perhaps its the coil. Both have 140,000 miles on them.

What I want to avoid is spending $300 on brand new injectors and then...oops there's the problem again, well I guess I'm out $300 and still have a problem.

There's got to be a good low-cost process of elimination method for testing this stuff out.

 

You have a code for a faulty MAF sensor, and the drop in O2 readings is preceded by a drop in MAF readings.

It also appears to be dropping out of PE mode. The long term and short term fuel corrections are locked at 128 and everything is going smoothly, then suddenly the long terms stay locked at 128 and the short terms start ramping up, in response to the falling O2 values.

 

I cleared the MAF failure code and it hasn't come back of course, because it was only thrown when I started the vehicle without the MAF hooked up and hadn't reset it since then.

It would make sense for the MAF reasings to drop, along with the o2 if 1+ cylinders weren't firing..and only at WOT.

So, the real question here is...what causes a narrow-band o2 to drop from 900mV to 80mV and then jump back up? I would assume either,

A. a cylinder full of fuel and no spark
B. a cylinder without fuel that fired

So what I want is a way to find out if I'm losing spark...or fuel at WOT.

I guess I'm going to have to burn $50 on a new coil (both coil and injectors have 150,000 miles on them now), and run pure injector cleaner through the injectors outside of the vehicle (since that's pretty much what an injector rehash house will do) and see if one of those clears my problem.

Just wish I could figure out what the problem is without spending tons of money and instead spending time.

 

Did you consider the issue of it falling out of PE mode?

 

I had assumed it was a reaction, and not a cause....
What would cause it to fall out of PE mode, aside from the throttle dropping? I understood that the o2 sensors were completely ignored in PE mode, would one of those reading a momentary lapse cause it to leave PE mode and make the problem worse?

 

PE mode is enabled by TPS position and RPM. An erratic TPS voltage would cause it to drop out of PE mode. So would an erratic signal from the Opti, if it showed lower than actual RPM.

 

datalog shows the TPS to be pretty consistent, however an erratic signal from the opti (RPM) is evident of course, and certainly it should be as I'm certain cylinders are not firing which is evident from the o2's, and how the car drives under this condition.

Yesterday it exhibited this condition during 50% throttle at high RPM's, so I'm inclined to believe it is a lack of spark. Since the vehicle was responding thus with the old opti a couple weeks ago, and still is after the new opti. I can eliminate that. Since it messed up at50% throttle at the same RPM's, I can presume it is not the injectors. So I'm left thinking it is probably the coil (150k miles on it) that is going out? Would this be a good assumption, or am I wasting $50?

 

Changed the coil today, no change.

Going to do what the fuel injector refurb shops do and run B12 instilled injector cleaner through the injectors to clean them to factory and try that, if it makes a significant change I guess it was the injectors and I'll need to replace them... if not.....nothing makes sense.

 

Figured I'd post the end result, so others can see how it was resolved.

Installed new fuel injectors...problem solved, old ones didn't leak and I had run tons of pure injector cleaner through them on the bench...guess it was just their time, or the miniature relay/whatever electro/mechanical device was failing.

so, short-band o2's showing minute bursts of low mV during WOT in this case = injectors failing.


So, the WOT seems to be around 880mV, I will dyno tune that some year from now when I get within 200 miles of an actual dyno...

my cruise STERMs and LTERMs are high, 130-150, and staying there, not sure how long it takes the PCM to correct all that stuff, but I'm tempted to believe that the formula sqr(43.5/39)*36 = 38.02 for the injector constant since these are ford SVO's is off by a bit, assuming my fuel pressure gauge was correct, 41-42psi operating fuel pressure, that should be more like 36....now sure off the top of my head if that will change what I'm dealing with "lean" to a more rich mixture or not, I'll sit down and contemplate it when I have time...

 

You said you are getting 45psi with no vacuum line connected. That's the pressure you use to calculate the injector flow rate. The vacuum compensated fuel pressure regulator drops the fuel pressure to compensate for the vacuum that the injector is flowing into. In effect, a 3x psi vacuum compensated rail pressure is equivalent to a 45psi DIFFERENTIAL flow across the injectors. Its the DIFFERENTIAL pressure that governs the injector flow, not the rail pressure.

For your situation, with a 45psi uncompensated pressure, the formula would be:

(45/39.15)^0.5 X 36 = (1.072) X 36 = 38.6 #/HR.

 

I actually started with 38.02 as the constant, and my sterms and lterms were consistently in the green (too rich). Since the old programming was for the same cam, I assume ballparking my BLM's to 128 using the injector flow constant will nail my WOT as well.
Switched it to 36.02 and they went from 140-150's to 130-140's, to say nothing of my knock count going up a bit during cruise speeds with good fuel.
So I am going to assume I need to set the injector constant to about 35.5, and that should be close enough for the majority of the powerband...there is no saving the idle-2500RPM due to the big cam overlap and numbers jumping everywhere with this stock PCM.

I've seen a few threads regarding needing to change the "injector offset vs battery voltage" table based on ford SVO's, and even found a table (looks like for a different editing program). But I haven't sat down and figured out where they got the formula so I can't convert it over...and it seems the problem only fixes some idle and starting issues, which I have none of.