VersaTune User Forum

So my challenges atm are like these:

With stock tune and with or without CS SRI+TIP I get fuel or boost cut, usually if wot on 3rd gear in 4500-5000rpm.
It's like momentary really heavy cutoff that I almost hit my head to the steering wheel, and it's usually on ramp when speeding to highway etc. when a cut is not needed.
I think it's easier to get the cut on colder weather. Now it's been like +12-20c

I tried to find vacuum and boost leaks with no luck (doesn't mean they don't exist )
Purge valve didn't leak when tried to blow trough it <3

Read from forums that ppl got rid of some cuts with AP or other non-stock tune, so I tried
Versatuner's base 98: no cut's whatsoever! But.. with Base98 or High load tunes I got CELs:
P2178: System Too Rich Off Idle bank1
P2188: System Too Rich at Idle bank1

LTFT was like 20.3% (check another attachment)
Changed to stock tune->no CELs but violent cuts came back.
Changed back to Base 98 tune->no cuts but CELs came back. You propably got the point now

I haven't calibrated the MAF yet, but I took a longshot and added mituc's smooth MAF cal to Base 98 and have now been driving just 20km's with it (check another attachment).

Service guide suggest these for those CELs:
• Misfire
• Front H02S deterioration
• Front H02S heater malfunction
• MAF sensor malfunction
• Pressure regulator (built-in fuel injection pump) malfunction
• Fuel pump malfunction
• EGR valve stuck open
• VTCS improper operation
• Purge solenoid valve improper operation
• Purge solenoid valve malfunction (stuck open)
• Purge solenoid hoses improper connection
• PCV valve malfunction
• Variable valve timing control system improper operation
• PCM malfunction

But what puzzles me is that when I run stock tune, no CELs are triggered - so if they were HW based CELs, wouldn't they appear with both tunes

So if you have experienced anything similar, or have tips what to do next, all pointers are most appreciated

I checked your logs and those fuel trims don't look good at all.
Also, the MAF CAL I posted is for the Cobb SRI. Check Skiptowncat's posts for a CS intake MAF CAL. However, the CS intake is closer to stock s with the base 98 tune and no MAF cal you shouldn't have been farther than like +5 - +8%, while your trims are on the negative side. If your MAF plugged in?

I believe that the -/+20% LT fuel trims is the maximum range the ECU will adjust. Anything higher than that in absolute values is to be considered a leak or malfunction and I'm not sure how it will react. A while ago I scalled my MAF CAL wrong and at -20% LTFT's my car was shutting down 2-3 seconds after starting the engine.

As for the cut you're experiencing... it can be from several reasons: MAF CAL, blown injector seals, bad plugs or coil pack, stuck wastegate leading to overboosting, disconnected wastegate solenoid boost hoses, blown VVT, worn HPFP piston or purge valve, and a lot other things. If you could take a log with a cut we can "guess" with more accuracy

Also, considering lines 1719 - 1726 in your "Short drive" log and looking at the wastegate duty cycle (under 10%) when hitting load way above 1 (1.7-1.86) with only like 50-55% APP I'd say that either your wastegate is stuck closed or some hooses are disconnected or connected improperly there. Same observation for 1731-1746 where it's clear you're overboosting with very little effort (you almost hit the MAP throttle reduction limit and went quite a bit above the load targets for the Base98 map with only 60% APP or so!). You're very lucky that your stock fuel pump was holding well.

And the wastegate/solenoid issue is only one of the possible issues your car has now. So stop going WOT and address all the problems in the turbo and intake area.

Alrighty, thanks for heads up mituc, i'll try not to wot

Just today i tried to reload the ordinary base 98 tune, but I bsod'd, so now when on stock tune I had a good
chance to finally log the cut It was just a short drive right after returning to stock, so there was no time to drive that 20miles first.
I read DTC's and there was P0234 Overboost condition CEL.

After logging I drove like 3kms and got P2178 with light.

Is there any other parameters I could log, or would you suggest just raw HW inspection as the next step?

Yes, I tend to believe that the wastegate is stuck closed or the control arm is not moving. You're hitting load 1.98 on stock tune with almost no wastegate duty cycle (lines 576-590 - try to clean a bit the logs you post, man! ), this meaning that the ECU is trying to correct and open the wastegate (which is why the wastegate duty cycle is dropping to 0) but the MAP doesn't drop, it actually increases. So it's definitely a wastegate problem.
In the meanwhile stay away from WOT or high PT. You can very easily blow the engine now (load almost 2 at 3000rpm with 50% APP is... holy shit!! Worrysome! Means that you can overboost a lot a even lower rpm's and push the rods through the block).

Just spray some brake cleaner on that control arm joint, move it by hand, use a brush, whatever, and make it move properly. You may need to get under the car to do that properly.

Btw, I have a friend with a similar problem on a 6MPS, his car is 100% stock. He just bought it a few months ago and before that the car was not used for quite a while. So I'm wondering if your car was also not used for a long period of time in the past few months.

mituc wrote:Btw, I have a friend with a similar problem on a 6MPS, his car is 100% stock. He just bought it a few months ago and before that the car was not used for quite a while. So I'm wondering if your car was also not used for a long period of time in the past few months.

Whoa again! Thanks for that, i'll check the actuator asap.
The car has been used for couple months by me, but I just recently bought it so I don't know
car's recent moves. It's been serviced steadily according to service book.

Yesterday I located the actuator and at least the rod was very rusty . Have to check it more closely this evening.

You can use a bicycle tire pump to actuate the wastegate manually to verify operation. Keep pressure below 30 psi/2 BAR.

Bugger, I saw Steve's hint a couple of hours too late

I tried to move actuator rod manually and it moved really little and was stiff - and rusty. I then
sprayed lubricant to both ends of the rod and moved it more. It started to move much more easily.

I drove a short test run and had the cuts, but I think the logs looked a bit different what comes to wgdc (pics with imap+wgdc).

I think I should order a new wga, because the old is so rusty. I might try to test the actuator with a pump if
it can be done without removing the wga (yes, the job getting it exposed was a real p.i.t.a with my hellokitty-quality tools).

You mentioned previously that I should clean up the logs before posting them. How should they be cleaned?

When I told you about cleaning the logs I was thinking to scrap the unnecessary lines with those extra few minutes of town driving prior to running the actual test you need to see in the logs
CSV logs work best, I have no idea what the graphs above mean

You can share the .vtlog file and anyone with VersaTuner can open it in their log viewer.

Here's the log from after greasing/inspecting wga.
Seems to me that it's not opening properly, yet it does better than before. New actuator needed?

p.s just noticed that I have only recorded stft sensor 2 and it's stabile 0,0-0,1% all the time.
Should record stft sensor 1 instead I guess?