I'd hate to have to go through the trouble of re-installing the flaps, but if that's the fix..
The thing i'm not getting is why it's still hesitant to rev, and down on power, above the 3k mark. It's like the engine is normal and happy from ~2900-3300rpm, and that's it. Below that, it sucks, above that, it's better but not right.
In reply to bluej :
There seem to be a lot of problems- but the spark issue you see between 2000 and 3000rpm is all due to the IMRC. You may not need to replace them, especially in the long run- but it's just a casue of the symptom.
lovely. 
Seriously, though, thank you so much for your insight!
alfadriver said:And yes, the IMRCs are closed, even at wot, up to about 3000rpm. Being knock limited is a bitch, but getting crappy combustion due to poor turbulence is worse. Remember that when you put a spark calibration in for your MS system...
At some point, 2004MY perhaps, they eliminated the IMRC completely. Any idea how that was achieved if the engine was so knock sensitive? I believe the same year they changed the MAF design a little, so I suppose that could be required with the IMRC deletion.
I always thought that switching to the intake without the IMRC setup would've been nice, but maybe it's more involved than it was in my head...
In reply to STM317 :
Mostly the ports changed. Nobody likes the IMRCs and as soon as they are put on, there's a team working to take them off. The Duratec Ranger was really bad, as we saw them fail doing durability testing.
The 2.5l head that he got is fine, and for sure, the *engine* doesn't need them. It's just that the computer expects them and runs the engine as if they are there. Which is the cause of that specific symptom. Once the MS is installed, and turbos added, it will run just fine without them.
alfadriver said:In reply to STM317 :
Mostly the ports changed. Nobody likes the IMRCs and as soon as they are put on, there's a team working to take them off. The Duratec Ranger was really bad, as we saw them fail doing durability testing.
The 2.5l head that he got is fine, and for sure, the *engine* doesn't need them. It's just that the computer expects them and runs the engine as if they are there. Which is the cause of that specific symptom. Once the MS is installed, and turbos added, it will run just fine without them.
This certainly has moved the MS install up in the schedule if it's going to run crappy on the stock PCM (I was expecting a little weirdness, and maybe some loss of power down low, but nothing this bad). I need it to pass emssions first, though. Then I'll have a few years to play before having to do it again. Plan was always to do a parallel install w/ stock PCM and the uMS running fuel and spark.
Something else is really wrong... I'll look at the entire track tomorrow at work, but when I see that the sensor voltage is close to 0 when you are at WOT, that's really wrong. Even though the sensor isn't being looked at, when at WOT, you should be pretty rich- which would have the sensor at .8 or higher.
Have you plugged in all of the rest of the stuff- PCV on both ends, the cannister purge system, etc?
Also, the fuel pump you put in, is it actually working right?
The long term fuel trim seems to be working correctly- taking 10% of the fuel out, which is the larger injectors. Most of the time, at least.
The log is just one long drive, right?
Oh- ignore all of the bank 2 data- it's not there. At least it shouldn't be there... was the truck always a 4 cyl truck?
alfadriver said:Something else is really wrong... I'll look at the entire track tomorrow at work, but when I see that the sensor voltage is close to 0 when you are at WOT, that's really wrong. Even though the sensor isn't being looked at, when at WOT, you should be pretty rich- which would have the sensor at .8 or higher.
That was my thinking, glad you agree.
Have you plugged in all of the rest of the stuff- PCV on both ends, the cannister purge system, etc?
I BELIEVE so. I've checked multiple times. It was down for over a year, so it's possible I messed up reinstalling some things.
Also, the fuel pump you put in, is it actually working right?
I BELIEVE so. I need to put a pressure gauge on the valve on the fuel rail to confirm, right?
The long term fuel trim seems to be working correctly- taking 10% of the fuel out, which is the larger injectors. Most of the time, at least.
OK, cool
The log is just one long drive, right?
Yes, if you downloaded the whole log, I started the log right before starting the truck. I let it idle for a minute or two before pulling out, and taking it for a short drive with a mix of throttle/speed conditions, specifically punching it in the problem zones multiple times to get those conditions logged. light throttle driving back home, parked, and let it hot idle for a while trying to get it to stall out like it has in the past, but it didn't.
Oh- ignore all of the bank 2 data- it's not there. At least it shouldn't be there... was the truck always a 4 cyl truck?
Yep, always was a b2300. I was always confused by that, so glad to hear you confirm it's ghost data. weird that there's anything at all for it though, right?
One thing I noticed and wondered about was that the engine coolant temp seemed to spike to and hold at close to 220/224*. Seems high, and I'm worrying that it was actually hotter than that but the sensor/PCM can't read above 224 for whatever reason.
Yea, measure the fuel pressure at the rail. Since you have a nice logger, any chance you can measure it while you are driving?
alfadriver said:Yea, measure the fuel pressure at the rail. Since you have a nice logger, any chance you can measure it while you are driving?
It's just a bluetooth obdii dongle and torque pro. I don't think theres a sensor in the system for fuel pressure for it to report on. I can do it the old fashioned way, will just take me a day or two.
Thanks!!
So looking at the data....
Both O2 sensors look to be working perfectly. And on that note, the second O2 sensor data would indicate that the catalyst is in great shape, as well.
The problem, to me, appears to be fuel flow related. When you tip in, there's an extended amount of time where it's running pretty lean. Where that makes the least amount of sense are the times were you are going WOT, and the lean time is like 5 seconds. While you can't tell what the actual a/f is, just that it's kind of lean- at the WOT points, that's where it is the most telling- at a bare minimum, the engine should be rich within a second, and then progress richer the longer you are at WOT. While the system would just tell you .8 to .9 V on the O2 sensor, just *being* rich would be good enough, and just being *lean* tells me there's a problem.
It's possible that there are leaks in the system, but that would be there all of the time, and not just sometimes. So triple check the manifold for leaks.
But I'd more focus on the fuel delivery system- pump, lines, rail, injectors. And the signal going to each of them.
Do you know why the original engine failed? It could be related to this fuel problem. And I know you changed the pump- but the problem may be something else- it could be the signal to the pump, it could be the signal to the injectors as well.
original engine lost cylinder four, holing the block/pan with the rod. PO said it was his son's truck, and he ran it low/dry on oil.
it feels like it's been running lean, so that makes sense to me. I'm ordering fuel test gear right now..
thank you!!
Not much time tonight. Replaced the ignition coil and poked around a bit looking for leaks/oddness. Does run smoother, but the large issue remains. At the end of the test drive it did throw a code for bank 1 too rich.
Fuel pressure test kit arrives tomorrow.
In reply to bluej :
Lest I ever forget, lots of fuel related symptoms can be traced to crappy ignition. A non-firing cylinder will look lean to the O2 sensor.
But go after the fuel system to make sure it's 100%. The goal should be to get it consistently to tell you it's rich if you don't change the injectors back.
alfadriver said:In reply to bluej :
Lest I ever forget, lots of fuel related symptoms can be traced to crappy ignition. A non-firing cylinder will look lean to the O2 sensor.
But go after the fuel system to make sure it's 100%. The goal should be to get it consistently to tell you it's rich if you don't change the injectors back.
Plan for tomorrow afternoon is to pull and check plugs then reinstall, test fuel pressure with a short drive as-is, then tear down, inspect all connections and swap the stock injectors back, w/ another drive and pressure test following.
Tested the pressure as-is last night. 62 psi, which seems to be in spec.
In reply to bluej :
Was that taken with the ignition on/ engine off, idling, or higher rpm?
Just wondering if it’s able to maintain pressure when flowing as well as static.
In reply to bluej :
Yea, I'm more worried about the pressure in a dynamic sense. It's pretty clear on your trace that the fuel is delivered correctly much of the time. But it's those times where you tip in where it go es bad. So if you can rig it up so that you can read it while someone else drives....
That was both pre-start and idling with a bit of stationary rev/hold to 3k or so. Yeah, I only had ~10 minutes last night and no helper, so that was all I could do. Hoping to be able to test a few other conditions driving this afternoon, then swap back the injectors and check a few things like crank/cam timing tomorrow morning.
While changing the injectors- take a very close look at the wiring. I've seen a car run, but occasionally cut out, as there was a slight cut in the wire. It could be something as simple as a cut or short that happens at the right engine rotation....
Just an FYI, that's a vac referenced pressure damper, not a regulator if I'm not mistaken. Regulation is still back at the pump
In reply to RXBeetle :
Yeah, I had forgotten about that (regulated at pump).
Alfa, your comment about bad combustion coming across as lean has had me wondering if there's a gap/spark blowout thing going on under load. Definitely feeling like I need to check the plugs.
Was able to test the dynamic pressure tonight. Stayed in spec under the various conditions. Injector swap tomorrow morning.
Edit: also got a code. P0172 - "System too rich, bank 1"
Stock injectors back in yesterday. Drives better, but still has weirdness with high throttle. The cycling from bog to normal-ish happens faster now, though. Basically makes the truck buck. So frustrating :-/
Couldn't find anything obviously amiss when swapping the injectors back. Plugs looked ok as well.
Here's the log from yesterday Drive link
Blue highlight is early WOT in the drive. Green is later. It did get better throughout the drive. Yellow was where it pulled timing all the way down to -7.5. Seemed odd.
It also threw the "imrc stuck open" code as I was parking it. Alfa, do you know how it determines that? Actually, right now I have the vac line running from the manifold to the actuator, skipping the valve. Maybe next step is to connect it properly. I'm guessing it can tell the actuator hasn't operated since it actually plugs in to the harness. Would that be enough to cause these driveability issues?
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