ok new opti,new icm, new fuel pump,new plug and wires, new inj, new fuel reg, new fuel filter.
now the problem is a missfire up top, with no codes being thrown. by up top i mean anything above 5k rpms.
after fully being warmed up the problems gets worse. it feels like the timing is being jerked outta the car. but its not, i have full timing, great fuel press. and great vacc.
any ideas? the problem has been around for a good 5 months.
the computer see's the car being perfect but its not. help please

 

Whats the spark plug gap at??

 

.045

 

is it only under wot conditions or any time it gets above 5 grand?
if its just any time its over 5k then i would look at spark issues
but if its only under WOT i would think fuel

hope this helps a little im kinda battling the same thing right now except im almost positive its either injectors or fuel pump
cause its only under WOT

 

Eventhough your Opti is new I would still think it's that. Did you install it or the dealership or someone else?

 

noticed you pretty much replaced everything but the coil. mine was doing the same thing and it ended up being the coil and coil wire

 

check your o2s. do u have access to a scanner?

 

yes the problem is only under WOT. and i installed the opti.
i was a GM tech, i just didnt like the dealership atmosphere. its not an installation problem.
the fuel is great through the whole rpm band.
this is why im lost.
i contacted EPP(exotic performance plus) and the told me they had a issue like this and they ended up replacing the opti like 6 times before the problem was solved. they had everything from msd to oem. and the one that fixed it was a dynaspark opti.
im lost. maybe i should replace the coil and see.
i have access to a scanner but it wont read my knock sensor, but thats not a problem b/c it never has, even before the issue started.
the 02's are responding normal. around 450 at idle and 950 at wot. like they should. fuel pressure is 46 psi at wot, vacc drops to "0", im gonna cry if its the opti again,b/c this would be the second one this year

 

At least it can be warrantied out so you're only out the time and effort of doing it.

 

lol. i know. but its been so long since its had any kind of throttle responce.everything went at once
and now this.im ready for a turbo kit but cant until i figure this out

 

What scanner are you using? What problem does it have reading the knock sensor? Are you saying it won't indicate whether you have knock retard? If it won't read knock retard (hard to understand why it wouldn't) you can just look at the spark advance and see if its close to the stock programming values (you don't indicate a custom tune).

If you have access to the scanner, can it read GM "enhanced parameters"? If it can, you can check the misfire count by individual cylinder, maybe helping you pinpoint the problem.

Do you really mean your O2 sensors stay at 450mV at idle, or are they moving rapidly over a wide range of 0xx-9xxmV's, with an AVERAGE value of 450mV? Allowing for the inaccuracy of the narrow-band O2 sensors, 950mV at WOT is a bit on the rich side at WOT. That may indicate a problem that is causing the PCM to pull fuel in closed loop using the long term fuel corrections, then defaulting to 0% correction in PE mode, because the long terms are pulling fuel out in closed loop, and causing it to run too rich WOT.

I was going to suggest the coil, but someone beat me to it. Are you sure there is no corrosion on the Opti harness connectors and the plug/coil wire terminals?

Since you have long tubes, I assume you have extension on the O2 sensors. Have you checked to insure all the connections are good?

 

the scanner is a palmpilot.using the LS1M program. it wont read my knock sensor.
see heres the thing, the car picks an choose's when to take timing away.
one time at 5k the timing was at 36 and another was 25. same rpm same gear.
there is not any corrosion in the terminals, and by 450mv i mean an average.
at wot theyre around 920-950.i dont have a custom tune. as of right now the fuel pressure is at 46psi at wot.
its a bit rich but that b/c of the adj reg. i could take some fuel out.
i just replaced the coil and no change.
heres my big issue and it doesnt make sence.
]i have listed everything i have replaced todate,
now the car runs fine no missing when its cold. i dont mean open loop either. its in closed loop but the warmer the engine gets the worse the condition is. the car is in closed loop 5 mins away from my house, now 15 mins into a drive it turns into a studdering monster above 5k.
and if the car pulls fuel in closed loop then it would continue into wot...(right?) if thats correct then the car would be lean. but the injector duty cycles are around 88-93%. not pulling fuel.
like i said i think im gonna end up calling msd and asking for another opti
guys thank you for the help..for real, your suggestions have helped alot.please continue to help me solve this problem

 

Again... a scanner can't "read the knock sensor".... it can only tell you if you are getting knock retard.
Advance depends on MAP (engine load) as well, so its possible for it to be at a given RPM and not have the same advance. There's also an elusive 3* that seems to come from the temperature being reported by the IAT sensor, so that might also be factor.
That's the fallacy of "tuning" with an AFPR... it doesn't work. Running at 46psi is forcing in more fuel than it needs. The PCM can compensate in closed loop, but you will definitely run rich in PE mode. Put the pressure back to 43.5psi (no vacuum line) at idle.
Think of what can go bad when it heats up - the optical sensor in the Opti, the IC Module (space it off the head with washers, as Shoebox suggests), wire insulation breaks down. Check the coolant temp sensor - are the readings accurate? Did you think about whether the O2 sensor extensions could be bad?
No.. if the PCM is adding fuel in closed loop, it uses the Cell 15 long term fuel corrections, and continues to add fuel in PE mode (WOT). If the PCM is cutting fuel (as in repsonse to your excessive fuel pressure) it will not continue to cut fuel in PE mode. It will either stay in Cell 15 and lock the long terms at 128, or is will default to Cell 18 and lock the BLM's at 128. You can't "tune" with an AFPR.

Injector duty cycles don't tell you if its running lean, or whether the PCM is pulling fuel. They tell you how hard your injectors are working to supply the amount of fuel the PCM thinks you need. If they approach 100% it indicates there's a good chance you may be running lean. You can only tell if its adding extra fuel at WOT by looking at the BLM's it uses at WOT.

 

ok the engine reading the actual knock....yes it is getting some knock.
.05-1.0.....but i dont know the values. does the sensor read 1v-5v. or is it a .0-1.0v?
and if thats the case, is it actually having an issue with spark or is the thing having internal knock.
if the opti is having an issue how would it create knock? less spark wouldnt cause a lean detonation.?right...... there would be more fuel, unless the pcm sees it and corrects for the fuel problem and pulls fuel.
the long term fuel trim was at -10% short term was around -3.
now take in to consideration that the only time i drive this thing to to figure the problem out, so all of its reading are at wot coming up to or at 5k.
thanks for the help and i hope this helps out a little.

 

The scanner can't read the knock sensor. The PCM feeds the knock sensor a voltage, and the resistance of the sensor sets the fixed voltage on the circuit. The knock sensor puts out a variable frequency signal, riding on the DC voltage of the circuit, based on the output of a microphone - which is what the knock sensor is. The knock module filters this audio signal, and only passes on to the PCM the magnitude of the audio frequencies it thinks are "true" knock. The PCM then retards the spark advance. What a scanner will report is the knock retard in degrees, and that number can range anywhere from 0.1* to 12.0* (stock upper limit). The scanner also reports the spark advance the PCM is calling for, and the number displayed on the scanner is the advance from the timing table (as a function of RPM and MAP), PLUS any offsets (such as the hidden 3*), MINUS the knock retard.

The optical sensor in the Opti tells the PCM the cam and crank postion. This is the postion that the PCM references the spark advance to, so if the Opti low res or high res pulse patterns are corrupt, or if the Opti is indexed incorrectly to the cam, the timing may be far enough off to cause detonation.

As far as the high voltage section of the Opti, if the engine is misfiring, the O2 sensor sees the unused oxygen in the exhaust, assumes the engine is running lean, and adds extra fuel that the engine doesn't need, causing it to run rich. "Less sparK" (do you mean weak spark??) will simply not ignite the fuel that is there, so its not going to lean anything out and not cause detonation.

The PCM can't "see" fuel. It can only see oxygen, via the O2 sensors. Misfires dump unused oxygen and unburned fuel into the exhaust - the O2 sensor can only "see" the O2, and thinks its running lean, and increases the long term fuel corrections.

Long term fuel corrections are continuously updated, starting when the PCM goes into closed loop. They are not "learned" at all in WOT (PE mode), so they do not reflect WOT operation. There are a large number of long term corrections, including a left and right for each of the 18 PCM operating Cells. What you appear to be quoting is the "average" long term correction. Significant fact is that your elevated fuel pressure is forcing the PCM to pull about 3% fuel from the standard calculation. Something else is causing it to pull an additional 7%. And, you should have values for both the left and the right bank. Sort term fuel corrections that are not= "0" indicate the long terms are not yet fully developed and may need to reach 13% before they stabilize.

You need a data log, showing the operation of the engine from a cold start, through closed loop initiation (about 200 seconds), a few minutes of variable "normal" driving to put the PCM into as many of the 18 cells as possible (cells are defined by various ombinations of RPM and MAP), and then a WOT pull through at least one gear all the way to redline. Just pulling random numbers with a scanner isn't going to tell you much. A good data log will show you a lot more.