Paging all Powerlogger experts

[87geeinn]

I have an issue that is popping up and I think it may be some electrical/grounding gremlin, yet I've been through the car's electrical system a gazillion times and know the car very intimately. Please take a look at the attached log, which is about 95% of WOT and see if anything really jumps out at you. It's obvious that all of the readings are flaky and unstable...from TPS, BLM, fuel pressure, boost, etc. I recommend looking at frame #539 and displaying BLM, fuel pressure, boost, and A/F ratio. The issue(s) should be self-evident then. I just can't figure this one out. All of the common electrical and fueling issues have been ruled out (i.e, battery cables are new, battery is new, alternator is good, grounds are SOLID, new fuel pump, fuel filter, etc, etc. Just seeing if something obvious stands out or maybe someone has had a similar issue.

The car runs pretty damned good but it just feels off and inconsistent in some way, as if it's not living up to its potential. I should also be able to run more than 23psi boost without lighting up the knock sensor like it does, even with this 92 octane crap in Hawaii. Also posted this on the TT forum to see if Eric can lend a hand. Mods in signature below.

 

[87geeinn]

Just to expound on my issue, take a look at frame #540. BLM correction is through the roof, fuel pressure is a full 6 psi lower than it should be, A/F ratio is all wonky even though wideband tracking is turned ON (yes, I understand boost must stabilize in order for the wideband tracking to work properly). Also not shown in the screen grab is how the TPS voltage is flaky. It should be noted that this was not 100% WOT, hence the low overall TPS voltage. I'm concerned with possible fueling issues and the knock sensor lights up a bit if I step into it all the way.

 

[earlbrown]

Do you have a Accufab fuel pressure regulator?

 

[87geeinn]

Do you have a Accufab fuel pressure regulator?

Yes, on my second one. Why my second one? This is why: http://www.turbobuick.com/forums/threads/defective-accufab-fpr-fixed-w-pics.398782/ And as an update to that thread, the regulator started acting up again, so I just ordered a new one.

 

[greeneyegi]

I have an issue that is popping up and I think it may be some electrical/grounding gremlin, yet I've been through the car's electrical system a gazillion times and know the car very intimately. Please take a look at the attached log, which is about 95% of WOT and see if anything really jumps out at you. It's obvious that all of the readings are flaky and unstable...from TPS, BLM, fuel pressure, boost, etc. I recommend looking at frame #539 and displaying BLM, fuel pressure, boost, and A/F ratio. The issue(s) should be self-evident then. I just can't figure this one out. All of the common electrical and fueling issues have been ruled out (i.e, battery cables are new, battery is new, alternator is good, grounds are SOLID, new fuel pump, fuel filter, etc, etc. Just seeing if something obvious stands out or maybe someone has had a similar issue.

The car runs pretty damned good but it just feels off and inconsistent in some way, as if it's not living up to its potential. I should also be able to run more than 23psi boost without lighting up the knock sensor like it does, even with this 92 octane crap in Hawaii. Also posted this on the TT forum to see if Eric can lend a hand. Mods in signature below.

im no expert by any means but at 23#boost youve got 38#FP,and your fuel correction is maxed at 30%
add fuel in the powerlogger,find out why the pressure aint 1-1

 

[TurboDave]

Make things easier, and try turning your boost down at least 3-4# and try a true WOT pull and see how things are.
BTW, how are your smoothing settings on the F3 page in the analog input settings box?

 

[earlbrown]

Yes, on my second one. Why my second one? This is why: http://www.turbobuick.com/forums/threads/defective-accufab-fpr-fixed-w-pics.398782/ And as an update to that thread, the regulator started acting up again, so I just ordered a new one.

The reason I ask is because TTA308 installed a brand new accufab unit and his PL files look EXACTLY like yours. He put his old Kirbins unit back on and it went back steady. When he got the FPR back from Accufab (they gave it a clean bill of heath) it still did the same thing.

When I took it apart and saw how it was designed, I'm amazed any of them work correctly. Needless to say he's still running the old Kirbins FBR.

 

[87geeinn]

Make things easier, and try turning your boost down at least 3-4# and try a true WOT pull and see how things are.
BTW, how are your smoothing settings on the F3 page in the analog input settings box?

Turned the manual boost control down two complete rotations but still ended up with ~23 psi boost. This is more of an issue related to my wastegate hole size and wastegate adjustment I think. Either way, it's VERY difficult for me to perform a true WOT run here in Hawaii due to the nature of the roads/traffic, but I digress. I was able to go WOT for a second or two but I was tickling the knock sensor and backed out of it. Something interesting to note is that I turned the smoothing from "medium" to "off" on the fuel pressure input in order to get a better picture of things (thanks for that tip, I didn't think about doing that) and look at the fuel pressure now! I'm starting to lean more toward a fueling issue now. Screeshot below, entire log attached as well.

The reason I ask is because TTA308 installed a brand new accufab unit and his PL files look EXACTLY like yours. He put his old Kirbins unit back on and it went back steady. When he got the FPR back from Accufab (they gave it a clean bill of heath) it still did the same thing.

When I took it apart and saw how it was designed, I'm amazed any of them work correctly. Needless to say he's still running the old Kirbins FBR.

Interesting information. Have any links to threads regarding TTA308 and his issue? I didn't come up with anything when searching his profile. I still have my other Accufab in a box. Perhaps I will throw that one back on there and see how things act then. Something I should note is that my "old" Accufab seals the return line with a flat, stainless disc seat. The "new" one looks identical but has a ball bearing-looking seat. Hmmm. Funny thing is, I used to have the Kirban regulator and only decided to go with the Accufab one because it looked cooler. I too never had any issue with the Kirban regulator. I may just have to revert back.

 

[87geeinn]

What the actual fuck. Dug out my "old" Accufab FPR and disassembled that one and the one on the car. Pics shown below are of the "new" one that was currently installed on the car. This just adds to my dissatisfaction of Accufab products as noted here as well as in the thread linked in post #4. Note the metal filings, grease, and piss-poor machining of the spring. You can also see how they have started using a ball seat vs. the flat disc seat. Reassembled the "old" disc style on the car and the fuel gauge doesn't flutter anymore. Plus it is holding steady pressure versus bleeding down immediately like it did before. This makes TWO Accufab FPRs that have been complete garbage. Gonna go give it a whirl in a few and see how things are.

 

[87geeinn]

Update: Boost backed down to 20psi, WOT run (no knock), but fuel pressure and A/F still erratic. Fuel pressure input smoothing set to "off." Car feels great but still not seeing that smooth and steady fuel pressure or A/F numbers as the wideband attempts to kick in tracking mode. Screenshot below and full log attached. Also, see video on my fluttering fuel pressure at idle (has done this with multiple gauges).

 

[Jerryl]

Make sure the hose is the correct size, and go back and zip tie ALL the hoses, especially the fpr signal hose. See if that stabilizes the fp a bit. Check to see if the vacuum at idle is stable, or followes fp fluctuation.

 

[Pronto]

Check the vacuum line fitting into the regulator. Mine was leaking. I can't say I'm impressed with the Accufab regulators.

 

[earlbrown]

There was no thread on TTA308's deal. He bought a timing cover from me and we met at Home Depot. I looked at his logs and took the brand new FPR apart in the parking lot. Needless to say I wasn't impressed with the design.. I'm no rocket ship but I couldn't figure out how it could possibly work at all.

From what I could tell from a witness mark the new unit might have worked better after the ball bearing beat a true sealing ring into the beveled seat. When I held it in the sun at just the right angle I could see the ball didn't have a unbroken contact point all the way around the seat circumference.


I'm wondering if the jumping around is from vacuum signal pulses causing the diaphragm to resonate (on top of a shitty seal). That poor seal was verified due to the accufab not holding pressure after key off. Putting the Kirban FPR on with no other changes allowed pressure to hold after shutdown.

I kinda wonder if anyone has an Accufab unit, a power logger and a FP transponder, and has smooth (and accurate) pressure and boost tracking.

 

[87geeinn]

Thanks for all the responses. I have eliminated all of the items that were suggested. The lines aren't zip tied at the moment only because I'm busy dicking around, removing regulators and what not. I'm not so much concerned with the idle fluctuations, it's when under boost is what I'm concerned with. The car used to have a nice, linear curve in the A/F and the wideband tracking worked like a charm...now not so much. Those rapid low spikes in fuel pressure is causing me to not to be able to push the car to its potential due to it causing a little knock. I'm out of ideas at this point. I do have a spare fuel pump that I might swap in but I really don't think that's the issue. Anyone got a Kirban regulator they want to get rid of, lol?

I miss the days of being back in Florida with good 93 octane fuel and being able to stomp on it and boost it up to 27 psi with no knock. Hawaii fuel (and roads) suck balls.

 

[earlbrown]

A leaky signal line would probably smooth out the undulations if it were leaky enough to have an effect.

Have you got a stock regulator you could put on there? With today's adjustable chips it might be worth doing the 'squish it slightly' to get 43 or 45 PSI at idle. It would be a good way to scientifically prove if it was the Accufab causing the rapid spiking.

 

[87geeinn]

A leaky signal line would probably smooth out the undulations if it were leaky enough to have an effect.

Have you got a stock regulator you could put on there?

Unfortunately, no. I threw mine in the trash years ago. Believe me, if I did, I would have thrown it on there to test that theory...and possibly scrunched it in my bench vise and be done with it. Hell, a brand new stock replacement is damn near $100.

FWIW, the signal line/vacuum line is intact. I think I'm going to make another margarita and just stare into the engine bay, hoping the solution pops into my head. Ever have those moments?

 

[earlbrown]

That's how I do all my troubleshooting. It's too easy to overlook something and paint yourself in a corner when trying too hard....


.....with the front of my brain concentrating on drinking and naked chicks, that leaves the back of the brain to process the data uninterrupted.

 

[TurboDave]

The wideband and fuel pressure traces are really jagged, indicating a possible grounding issue. Where are those two sensors grounded exactly?

 

[Ttype6]

I turned the smoothing from "medium" to "off" on the fuel pressure input in order to get a better picture of things (thanks for that tip, I didn't think about doing that) and look at the fuel pressure now!

What fuel pump? Hotwired? It would be nice if you could observe a gauge to see if it fluctuates. If the boost is actually fluctuating,you can expect the fuel pressure and WB to fluctuate.

 

[Pronto]

How does the "all billet" regulator that a few vendors sell look inside? Do they have a better design for the seal?