MS3v3 System for CNP and EFI/Turbo "Beetle"

[kangaboy]

Cleaning sensor grounds and battery posts seemed to have fixed the major issues I was having. Made it to work with minimal issues. Still need to get a bit of autotuning going to fix a few hiccups that were caused when I tuned with the bad grounds, but for the most part, grounds seem to be the root cause of the issues this time.

26663

[buguy]

Yeah that's a bummer. I spent 2 days trying to tune mine with a severe intake leak. Had it all jacked up.

[Piledriver]

MSQs: save early and often... only takes seconds to "undo" an error if you have backups.

[buguy]

Yep. "Save as" is the key

[kangaboy]

Ok...been a while since I posted, but after putting some more miles on the beetle over the last few weekends, the problem had gotten a lot worse. I thought the ground cleaning session that I performed helped a bit, and it may have, but not in the area that I am having problems. So long story short, I was out driving last weekend, did a couple errands, and about 3 miles from home on the 20 mile round trip, the motor just seemed like it was about to die. The bogging went from what it usually does, to much much worse. I didn't have my laptop on me, but last time I looked at it when it was doing this, it was just the AFRs that were out of control. If I would give it any throttle it would just seem to bog harder. I was able to limp it home, and while rolling down my drive in neutral, it actually died before I rolled it into the drive way. I did just a quick under the decklid check and didn't notice anything. Wasn't hot, had oil, had fuel. It only seems to do it after it is completely warmed up, and it doesn't seem to make a difference if I'm cruising or accelerating. I was so pissed I just left it and went to work on house projects.

Next afternoon I had to move it around in the drive way and it started just fine. Idled fine, moved it around just fine.

Talking with some folks, I have come up with a couple ideas:
-fuel pressure- maybe my Chinese pressure regulator went south? Not getting enough fuel anymore?
-arcing spark plug wires- It kind of felt the same as when one of the wires was arcing in my wife's F150. It would make sense why the AFR was out of control if a cylinder or two weren't firing and it was sending that unburnt fuel down the exhaust pipe. I have kind of ruled that out after the last incident though, because I wouldn't think this would cause it to progressively get worse, and ultimately die in the driveway.
-dead A/F sensor- again, I wouldn't think this would be causing issues if I wasn't actively auto-tuning.

I'm kinda lost. I don't know what else I can give you guys because I wasn't data logging or tuning at the time. I guess I could start logging and just keep driving up and down a mile or two stretch of highway around my house until it happened again. Other than that, I'm completely lost on this one.

[buguy]

I don't know if it translates, but I had a car with carb act like that and it ended up being the coil would start jacking up when it started getting hot.

[kangaboy]

I plan on taking a good look at it this weekend, thanks for coil input. I'll give them a thorough check.

Where are you guys putting fuel pressure sensors? I found a Tee that can mount it inline and still be able to attach it to my hardlines and fuel rail, but curious about where in line. In front of all injectors, after injectors, directly after pump, in front of regulator?


Pressure Sensor


Tee

[Chip Birks]

My regulator has a port built into the regulator, that's where mine is.

[buguy]

Mine too. But I also have one on the old CB fuel rail.

[kangaboy]

I have this...

https://www.rockauto.com/info/31/BA1580073-1__ra_p.jpg

Curious if it crapped out on me and if I should splurge on one from Mario

[buguy]

I bought this one. https://www.tanksinc.com/index.cfm/page ... prd488.htm

[kangaboy]

Alright all, I purchased a new fuel pressure regulator with a port to install a sensor. I have a general idea of how i would like to plumb it, and my idea includes running hard lines from the fuel rail to the FPR. With that said, is it an ok idea to mount the FPR on the fan shroud? I figured the fan shroud was pretty solid in regards to the manifold/fuel rail, but if there was any movement of the shroud, it may cause issues in the future.

[kangaboy]

Fuel Pressure Sensor mounted and plumbed. Took the bug for a 15 mile round trip...same issues (bogging/lean spikes). I have the fuel pressure sensor mounted to the FPR and reading in TunerStudio and it shows ~30psi at idle. I now know that the bogging that I am experiencing is a fuel issue, and not a spark issue, as the AFR spikes and shows lean. If it was spark, it would be fat. With that said, the fuel pressure seems pretty constant, which makes it seem like there is plenty of fuel flow to the rails and injectors. I'm lost boys...

[Schweg]

Do you have an AFR gauge also or are you going straight off tunerstudio? And if so what type?

I had an issue with my gauge and TS being way off leading to some interesting conditions.


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[kangaboy]

I'm just going off of the tuner studio gauge, as I don't have one in the car. I thought it may be the AFR sensor because it was being a bit erratic, but then thinking again, if it was the sensor then it shouldn't be doing it when I am not tuning. The AFR readings are coinciding with the way the motor is acting and the drivability of the car, so I feel like it is reading correctly. I could be wrong though.