Loss Of Power Louder Exhaust

[Trex]

Hey guys,

i havent boosted my car hard for a few weeks, and noticed when i do boot it, the car loses power and surges a small amount, i have more power on slight throttle than 1/4 1/2 and wot. the exhaust has gotten noticeably louder from the tip, and has backfiring on de-accelerating. You can hear the differences from the turbine at different throttle positions, so i am guessing it is still boosting fine. I have an inkling it could be that the cat has let go and caused a restriction? obviously i would check it myself, but one of the bolts for the cat are tight and is almost impossible to get to without a hoist and the right tools.

edit: The exhaust sound is clean, and it doesn't want to rev quickly in neutral like it should

I've searched online and called some friends but no real answer.

Edited February 25, 2014 by Stagea97

[Trex]

Need this fixed ASAP. Any ideas are welcome!

[stock stagea]

I would go to an exhaust shop and get them to check it out(measure the temp in front and behind the cat), if that isn't the problem you might also find that you have lost a couple of blades on the exhaust side of the turbo, same thing happened to my skyline. Good luck and keep us posted.

[picklesRs4]

Bit of a noob suggestion bit maybe it's the air flow metre? Once you push it harder it could cut out and cause backfire/popping noise

[Trex]

Thanks for the help stock stag and pickles

Sleek came over because I was too sick to work on the car. We tested tps, checked plugs etc etc. I called Jez and another friend and dales friend...

Everyone pointed to the afm being the culprit, I've never heard of the afm doing this so I was skeptical. But sure enough dale took it for a run while it was cold and it ran fine on the cold map, then when things started to get hot it started to play up a lil. Hit it with some contact cleaner and I'll have to go for a drive this weekend.

Also with the afm problem, we had a problem with the auto not wanting to manually engage 1st or 2nd or snow mode or reverse chime etc. we freaked out until we remembered the basics 'check the f**king fuses before you do anything else' sure enough new fuze and everything is now good.

Should I buy a brand new one for $80-$120 comes with 12 months warranty. Or just another second hand for $20.

I won't worry about re soldering. Because I had an afm that f**ked out and re soldered and didn't make a difference.

Cliffs: I'm on the train killing time.

Also got some new tyres. Calling the nsw tein distributor for the rear 345mm springs

[scotty nm35]

Better not solder it, just buy another second hand one that needs soldering too.

[sleek3]

good thing it was only a fuse ay.....glad to help anytime...

[Trex]

Better not solder it, just buy another second hand one that needs soldering too.

Second hand one is a money back guarantee....

Could have just said buy a new one. Which I will be doing now.

[Lakes101]

I seem to have the same issue with my m35 surges when in auto mode only but when I'm in sequential mode it doesn't happen at all. Also seems to stall like it loosing air have had to unplug a fpr to keep it from stalling which is making it run rich. What could the issue be here guys?

[scotty nm35]

Your Nismo ecu. With the stock one in place it runs fine yes? Time to stop stuffing around and Emanage the thing.

[Lakes101]

I plan to Scott just saving for one and dyno time. But yeah fitted the stock one back into for the 3hour drive back upto Sydney. It runs perfect didn't skip a beat, idled low around 500 but no issues at all. :-/

[Trex]

Wouldn't have thought a 'nismo' ecu would have broken down already

[Lakes101]

Neither would I mate.

After reading the nismo ecu thread started by Craig I was super pumped to get my hands on one but I'm disappointed on the outcome after installing it really. Fuel economy when through the roof was getting 12l/ 100km with standard and 32l/ 100kms with the nismo the engine was surging and kept on stalling on me. It did shift better and have better low to mid torque and spooled up earlier but at the cost of reliability. Pritty bumbed about it. Not sure why it would run lick that though. :-(

[Trex]

Sounds odd what was the sellers setup? was it the exact same box and engine as yours?

[Lakes101]

Yeah I know:/ yep same power plant vq25det ARX nm35 stagea had a high flow if think and some other minor mods as mine so don't think that should be the issue as the nismo ecu as all set to the same spec for the vq25det. Strange hey. What do you mean by box btw? How's your car running now bud all good I hope?

[Trex]

gearbox. May have been damaged in transport? sucks to hear man

Yeah running good now! Sprayed it with some afm cleaner and it seems to be holding up. I'll eventually buy a new one.

[Lakes101]

As in transmission? Yeah seems to be fine bro never had a problem with it and runs fine with the stock ecu in oh well shit happens hey! :-/

Good to here mate a quick spray is a much cheaper option to try first but they do seem to let go eventually. :-(