Help! -Loss Of Power And Engine Shut Down After Boosting Hard

[rondofj]

It could be the bov causing a lot of reverberation? But I'm guessing it's the stock intake pipe, and it's a recently occurring issue, so I doubt it's that. I wouldn't expect it to have much to do with the bov.

My money is still on the O2 sensor. Disconnecting it does not necessarily mean it CAN'T be the O2 sensor, because the ECU is still expecting it's feedback. You would have to edit the tune to set the O2 feedback temp very high to effectively rule it out. But then again, I would expect it to be causing more issues at idle/cruise if there was a problem with it, not only at decel. Are there any other issues, apart from the cutting out at high rpm? Does it idle nicely, cruise nicely, etc?

This is why I suggest you take it to a tuner. You might be getting a DTC which could be checked through consult. So if you insist on doing it yourself, at least get a consult cable and download ECUtalk or a similar program and check your codes, you might save a lot of time.

*EDIT* Just read your O2 sensor is not done up tightly. Speaking from experience, you need to do that up tightly to get it to seal properly. I cross threaded my stock O2 by putting it in when the exhaust was hot, and ended up with a big exhaust leak. I suggest you fix things like that before continuing to diagnose, it's such an easy fix and might be the issue all together.

Ok, I'm hoping against hope its the bloody O2 sensor. There's no other problems whatsoever, but as mentioned earlier, when my friend took it for a run (O2 sensor connected), it felt noticeably sluggish and missing a fair chunk of power and torque, boost was ok normal, revving to 7000rpms was normal and clean, but there wasn't much shove/kick and it was slow to come too, had to hold pedal to floor to get the same amount of kick that normally comes at 3500-4000rpm. It was a HOT day, engine bay temps were hot as. Then yesterday I disconnected the O2 sensor (AND TIGHTENED IT WELL) and it felt powerful and snappy like before, no dramas. Boosting, revving, engine sound and drivabilty has always been smooth and clean. Maybe the ecu didnt pick up the O2 sensor then (when it was sluggish).

Now the only remaining problem is the engine shutting down on quick throttle release, whether after WOT or coming to a stop at lights or pulling into drive...

Might need to get a little laptop, ecutalk and a Nissan consult cable (cable off ebay good??) This is what I found: http://www.ebay.com/itm/Nissan-Consult-Diagnostic-Scanner-Cable-14-pin-Reader-NSN-OBD-Fast-USA-Ship-/260924083182?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ANissan&vxp=mtr&hash=item3cc0498bee

Or wait to get licence back and off to Yavuz..

Edited January 9, 2012 by rondofj

[rondofj]

Hanaldo, O2 sensor is already tight now, before I went for a drive yesterday.. Power is back..but that was just one test so... BTW what is DTC, I only know TDC - top dead centre (timing).. The loss of power earlier COULD have been from the O2 sensor being only hand-tight then..

Edited January 9, 2012 by rondofj

[Sarumatix]

I'd still be thinking boost leak, I had this issue with an auto as you said. Turned out it was a combination of a dieing AFM having a dry solder joint and a slight boost leak on the added t for a boost gauge.

[Hanaldo]

DTC is diagnostic trouble code. Basically error codes recorded by the ecu.

[QWK32]

Still running the stock rubber inlet pipe, the one from the AFM to the turbo? If you are, have you looked into the fact that it may be sucking closed under full throttle? Big restriction there that will cause poor performance.

It is getting hotter and engine bay temps would be getting hotter making the rubber softer. It is a common issue, search for "$5 intake mod" and you should find a whole DIY thread about fixing it.

[blind_elk]

When engine shuts down, three lights come on in dash- battery light, engine light and teapot light (oil press?)

Well, when the engine shuts down, the key is still in the "run" position, and the lights are saying "no charge", "no oil pressure" and "no engine(?)". If you notice, these three are on before you ever start the engine (just before you switch to "start").

You've got a tuneable ECU - add some fuel and timing to the rpm bands just below the idle band, see if that helps with the stalling.

[DVS JEZ]

Turn your idle screw up higher Ron, u cleaned the aac it may need resetting. Wind it out a full turn and get ur mate to see if its fixed. Please stop posting if u drive it urself. Just say "ur mate was driving". We are not the only ones that read these forums

[rondofj]

Hehe good idea Jez. I am very grateful to u guys, ya all rock bigtime .. To Qwk32, I am yet to make a proper steel intake, when Jez tuned my car we made absolutely sure the intake wasnt sucking shut, and it didnt let us down thankfully. Same mods n boost then except the dump.

As for adding fuel n timing to the idle points, I dont have the Nistune licence, laptop and cable to do so yet, but hopefully soon. I trust Jez had got this right when he tuned so it could have gone off whack with the new O2 sensor. What say DVS?

I will definitely turn that idle screw to fully 'open' counterclockwise, correct?? Then get my mate to go for another run. To me it seems more n more a lack of air/ vacuum issue, the way it happens, like sucking all the air out from the intake on quick throttle release..

[BRUNSKIGTST]

bad cat?reboot of ecu?

Edited January 9, 2012 by BRUNSKIGTST

[rondofj]

Cat's good of course - a 100 cell metal item, and ecu's been reset - today after work I will turn that idle screw open because I know I closed it too far to shut up the idle when I cleaned it.. This WILL solve my problem.. Well I think so..

[dori34]

get it tested for vacuum leaks at a mechanic shop. if you wanna DIY, youtube search testing for vacuum leaks.

ps: i love your ghetto exhaust holder with 2 hose clamps LOL

[rondofj]

ps: i love your ghetto exhaust holder with 2 hose clamps LOL

hahahaha I have no choice mate, I cannot drive to the exhaust shop...Was gona get some metal ties for the time being..

[GTScotT]

Can you do something very simple for us and turn the boost down?

Set the boost back to the lowest it can get.

[rondofj]

I will do the idle screw thing first tonite and let you know. What does the low boost do? Prevent less boost leak / air getting sucked from a suspected leak? I'm scared to play with the manual boost control as when I wind it back up, I do not want to overboost past 12psi..

[rondofj]

Car fixed guys, i mean like completely, just fixed it now..no more engine shutting off, wheelspin in first n second easy as pie and a good solid shove in nuts when i want...

So what was the problem you ask. Such the simplest of all things fellas...eeeehh ..grins bigtime like a cheeky mofo...shut the fk up and tell... Eeeeh will wait for a few guesses, ... Then the story comes, hope to help others with same problem

[rondofj]

Wasnt the idle screw but close..

[Sinista32]

Suspense

Drum roll........................

Cmon spill it

[rondofj]

Toot toot, guess guys...

[rondofj]

Ok before i go to bed... It was one of those straw vacuum hoses onto intake manifold from near the brake servo area, broke free from a crack when i cleaned the aac valve, only just saw that it was hanging down when i went to loosen the idle screw.. Of all the little things causing such pain..

[BRUNSKIGTST]

what a pain lol, i know how you feel, today i hit a pothole hard but not hard to buckle the wheel and car starting to go all funny like want to shut off and stuff so im geussing some thing went lose lol tmz im go over engine bay and tighten everything i see and see if things are connected lol,