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Here is an email I sent to my tuner. I'm hoping he can find the reason my car hit fuel cut and that it's a clue to WTF is wrong with the car. I'm posting it here because it's surely mechanical and I'm drawing a blank as to what the problem could be. I'm also in a hurry because I LITERALLY registered for an HPDE the day before all this **** happened.
EvoScanDataLog_2017.05.26_12.59.26 shows where the car seemed to hit fuel cut. Ever since then, the car is spooling slow and running rich. It happens at row 138.
EvoScanDataLog_2017.05.10_20.58.28 shows where the car was performing before.
EvoScanDataLog_2017.05.28_20.53.42 shows what the car is doing now.
I did a boost leak test up to 28-30psi with no leaks.
I swapped MAF sensors today. Doesn't seem to help at all. I attached pictures of both. Do I need to disconnect the battery to let the car relearn or anything?
I'm stumped. Ideas?
I will post the logs after my Tuner has a chance to review them. Here is the before and after dyno charts. I picked a couple of logs before and after the "incident". Peak power and torque seem mostly unaffected in regards to number and RPM.
It's just spooling lazy and maybe running a bit less boost.
Dead turbo?
The "incident" was my hearing a "pop" and the car did the "felt like it hit a wall" thing. i thought, for sure, that I lost a coupling. I got back on the gas a bit.. all seemed well, then i floored it again: another pop/wall. The only two times I've had a car do something like this was a coupling tearing a hole in itself or a turbo dying. Seeing how the car did the pop/wall thing twice in a row makes me feel a little better. Maybe. the car now drives without hesitation, but is slow to spool and AFRs are off.
***EDIT because I was sick and forgot a key part of the story. When I got the car home, I found the cap had come off the inside of the air filter. That's what damaged the MAF sensor. I had assumed the cap coming off resulted in change of air flow + damage to MAF = reason for my problem. I repaired the filter for testing purposes and swapped MAFs. No change.
I had exactly the same problem recently and ended up replacing the MAF. The giveaway is the drop in load. Check to see if there is a corresponding drop in MAF Hz to confirm.
I pulled my old MAF apart to see if I could see any damaged electrical components. They all looked good. My conclusion was that the mechanical components, mirror and support had worn or become damaged, (190k on them), because it didn't respond correctly when the Karmen vortices hit it at over 800 Hz.
Did you boost leak test, I had a similar problem recently and it was a vacuum hose came off a nipple behind the block, I believe off of the Fuel pressure regulator solenoid
Dude. Those plugs look like they have 30k miles on them. Did you not replace them with the short block? You told me they were new on FB chat...LOL
Also, you're using WAY WAY WAY WAY too much anti-seize on the plugs. You only need a dab. It spreads well.
I didn't put the plugs in, but was told he put the new ones in there. If he didn't then a new set got thrown away. That would be about my luck LOL. If these are the old plugs, they will have about 3500mi on them.
Densos are gapped at .22 and in. Still no change.
Gary says to lean the map out and see what happens. Mechanically, I can find NOTHING wrong other than a LICP coupling that had a couple cracks but didn't go all the way through. I ordered a new one.
When you have a boost leak.. wouldn't the load increase, not decrease?
Originally Posted by 4G63_EVO
Did you boost leak test, I had a similar problem recently and it was a vacuum hose came off a nipple behind the block, I believe off of the Fuel pressure regulator solenoid
Two tests. I checked all vacuum lines a couple times. None of them are leaking, assuming I'd notice with the TB closed.
I'm sick again, so I'm high on cold meds and probably missing something obvious LOL.
I didn't put the plugs in, but was told he put the new ones in there. If he didn't then a new set got thrown away. That would be about my luck LOL. If these are the old plugs, they will have about 3500mi on them.
Densos are gapped at .22 and in. Still no change.
Gary says to lean the map out and see what happens. Mechanically, I can find NOTHING wrong other than a LICP coupling that had a couple cracks but didn't go all the way through. I ordered a new one.
When you have a boost leak.. wouldn't the load increase, not decrease?
Two tests. I checked all vacuum lines a couple times. None of them are leaking, assuming I'd notice with the TB closed.
I'm sick again, so I'm high on cold meds and probably missing something obvious LOL.
Everything about that log looks a little erratic. It almost seems like it actually is hitting a boost/flow cut? I'm sure the boost cut settings have been checked, correct?
May 28, 2017, 09:49 PM
