Z not running, no codes, help?!

[ViCiouS]

EDIT: Solution at end of thread. Post 11


2016 has not been a good year for my Z...

In January I found out my intake plenum was cracked AND my fuel pump went out...at the same time. Both got replaced, along with a new battery.

Z drove great again, up until Saturday. Saturday it felt like traction control would go on whenever giving moderate gas and hitting 3500 rpm. Shut off traction, put in slapshift mode, and it stopped happening.

Come Monday I started driving to work, it was doing it with traction off and in slapshift, something is definitely wrong. Went back home, and took the Ducati to work. I searched the forums far and wide to find an extensive thread by ak370z or something similar about camshaft sensor issues causing a 3k-3.5k limp mode. But the car was always still drive-able.

So yesterday i take it out to record the issue, assuming it will still be semi-drive-able. I go about a half mile in the first attached video. Any point you see it hang at an rpm then start dropping, is basically giving it hard gas but nothing happening. Towards the end of the video I have to pull off the road twice, let the car rest a sec, and then it starts going again. Right after the video ended (pulling back on my street) the car sputters and dies. The 2nd video (shorter) is current situation. Non-drive able.

There is no CEL. Fuel pump was just replaced 3 months ago. I do have a hole in the flex of the stock y pipe, but i really doubt thats enough back pressure drop to cause major issues that come out of the blue. I already tried resetting the ecu as well. I've basically parted out, current mods are only Stillen headers and crank pulley which have been on over a year with no issues.

1 - My first thoughts are to clean the MAFs and TBs first, make sure the tb's are opening as well. Recommendations for a good cleaner?
2 - Anyone know of a good way to fix the flex pipe w/o cutting and welding a new one?
3 - Could my fuel pump be crapped out again?! what would cause this.

Help?!

Drive around, can't really tell before 1:20, but starting there bogs down while giving hard gas, have to pull over, then revs fine, bogs again in 3rd, try giving more gas and nothing happens, slow down and shift to first, almost stalls, then randomly accelerates again: https://vid.me/9LGo
Car barely starts and dies, oil temp, voltage, gas, etc all good: https://vid.me/7kFb

[FairladyZ40th]

Originally Posted by ViCiouS

2016 has not been a good year for my Z...

In January I found out my intake plenum was cracked AND my fuel pump went out...at the same time. Both got replaced, along with a new battery.

Z drove great again, up until Saturday. Saturday it felt like traction control would go on whenever giving moderate gas and hitting 3500 rpm. Shut off traction, put in slapshift mode, and it stopped happening.

Come Monday I started driving to work, it was doing it with traction off and in slapshift, something is definitely wrong. Went back home, and took the Ducati to work. I searched the forums far and wide to find an extensive thread by ak370z or something similar about camshaft sensor issues causing a 3k-3.5k limp mode. But the car was always still drive-able.

So yesterday i take it out to record the issue, assuming it will still be semi-drive-able. I go about a half mile in the first attached video. Any point you see it hang at an rpm then start dropping, is basically giving it hard gas but nothing happening. Towards the end of the video I have to pull off the road twice, let the car rest a sec, and then it starts going again. Right after the video ended (pulling back on my street) the car sputters and dies. The 2nd video (shorter) is current situation. Non-drive able.

There is no CEL. Fuel pump was just replaced 3 months ago. I do have a hole in the flex of the stock y pipe, but i really doubt thats enough back pressure drop to cause major issues that come out of the blue. I already tried resetting the ecu as well. I've basically parted out, current mods are only Stillen headers and crank pulley which have been on over a year with no issues.

1 - My first thoughts are to clean the MAFs and TBs first, make sure the tb's are opening as well. Recommendations for a good cleaner?
2 - Anyone know of a good way to fix the flex pipe w/o cutting and welding a new one?
3 - Could my fuel pump be crapped out again?! what would cause this.

Help?!

Drive around, can't really tell before 1:20, but starting there bogs down while giving hard gas, have to pull over, then revs fine, bogs again in 3rd, try giving more gas and nothing happens, slow down and shift to first, almost stalls, then randomly accelerates again: https://vid.me/9LGo
Car barely starts and dies, oil temp, voltage, gas, etc all good: https://vid.me/7kFb

Why is the airbag light on? Maybe the computer thinks you were in a wreck and its trying to prevent you from driving since some cars do that now?

Also when you remove the MAF sensors or the throttle body to clean it or get upgraded intakes id suggest doing the idle relearn along with the computer reset.

I'm theorizing maybe your new pump is flooding the engine? Or you ended up getting a bad pump? It got clogged unfortunately? How about injectors? (I doubt it's any of these since it seems like it is a computer issue... Just my thoughts as to possible reasons. Sorry if it doesn't really help :/

[SouthArk370Z]

First thing I'd do is get an OBD/CAN scanner and see if any DTCs are present. Not all DTCs trigger a CEL.

Edit:
PS: I can't see the vids. Just a black box.

[ViCiouS]

Originally Posted by FairladyZ40th

Why is the airbag light on?
Also when you remove the MAF sensors or the throttle body to clean it or get upgraded intakes id suggest doing the idle relearn along with the computer reset.

I'm theorizing maybe your new pump is flooding the engine? Or you ended up getting a bad pump? It got clogged unfortunately? How about injectors? (I doubt it's any of these since it seems like it is a computer issue... Just my thoughts as to possible reasons. Sorry if it doesn't really help :/

Airbag is passenger side control module, been like that almost 3 years.
I'll try the idle relearn, forgot about that. I downgraded back to stock like 6 months ago lol. Never had problems with full bolts ons, now everything is failing me :/
I would think flooding or bad injectors would be gradual, not working perfect one day, bogging the next.

Originally Posted by SouthArk370Z

First thing I'd do is get an OBD/CAN scanner and see if any DTCs are present. Not all DTCs trigger a CEL.

Edit:
PS: I can't see the vids. Just a black box.

Ordered a OBD scanner for iphone, doesn't get here till Sunday though and can't get to autozone so..

[FairladyZ40th]

Originally Posted by ViCiouS

Airbag is passenger side control module, been like that almost 3 years.
I'll try the idle relearn, forgot about that. I downgraded back to stock like 6 months ago lol. Never had problems with full bolts ons, now everything is failing me :/
I would think flooding or bad injectors would be gradual, not working perfect one day, bogging the next.




Ordered a OBD scanner for iphone, doesn't get here till Sunday though and can't get to autozone so..

Hmmmm... Well I mean it only happens when you punch it? But if you slowly accelerate its ok? Have you tried that? If it dies only when you punch it then yeah man maybe clogging....

[MagmaRed370z]

Very weird issue for sure. Looks like you got a bad fuel pump? So many things that can cause issues like this. Double check everything again to see if you miss something. CPU reset, idle Re-learning, try your new Code scanner to see if something shows up. Injectors maybe? Bad old fuel?

(Miss the good ol times when cars didn't have all these technologies and advanced CPUs ("features") and auto-shutdowns to "prevent" things to happen, making it a real pain to keep driving the car....)

[ViCiouS]

Originally Posted by FairladyZ40th

Hmmmm... Well I mean it only happens when you punch it? But if you slowly accelerate its ok? Have you tried that? If it dies only when you punch it then yeah man maybe clogging....

Most noticeable when moderate throttle, complete bog when full throttle. Extra slow acceleration with little throttle. as you can tell from the video though, it's not consistent. Randomly works, randomly isn't. From my understanding (and experience on bike) fuel filter or blockage consistently has an effect at rpm or throttle levels.

Originally Posted by schellingr

Very weird issue for sure. Looks like you got a bad fuel pump? So many things that can cause issues like this. Double check everything again to see if you miss something. CPU reset, idle Re-learning, try your new Code scanner to see if something shows up. Injectors maybe? Bad old fuel?

(Miss the good ol times when cars didn't have all these technologies and advanced CPUs ("features") and auto-shutdowns to "prevent" things to happen, making it a real pain to keep driving the car....)

Hoping it's not the fuel pump, that was a surprising pain the the *** to change. Might as well take it out and check connections though..

Someone has suggested old gas, or gas with condensation/water in it. Going to try an additive to address this. Hopefully would be the easiest fix.

[FairladyZ40th]

Originally Posted by ViCiouS

Most noticeable when moderate throttle, complete bog when full throttle. Extra slow acceleration with little throttle. as you can tell from the video though, it's not consistent. Randomly works, randomly isn't. From my understanding (and experience on bike) fuel filter or blockage consistently has an effect at rpm or throttle levels.



Hoping it's not the fuel pump, that was a surprising pain the the *** to change. Might as well take it out and check connections though..

Someone has suggested old gas, or gas with condensation/water in it. Going to try an additive to address this. Hopefully would be the easiest fix.

Yeah man I had that same issue. Went away when I did the full clean of the intake system (MAF, throttle bodies, filters etc.) and DO THE IDLE RELEARN. I forgot to do that and I had the same issue man. Once I did the relearn no more problems. And yeah more likely than not it's also the fuel pump. My tuner told me I was getting too little gas to the engine at 100% pump capacity and I have minor start up issues still today. Though I fixed the bogging and stalling.

[B&W_Evader]

How about clogged/melted catalytic converter. If you run super rich or have a cylinder missing you can melt it. Run open exhaust can let you know if it's that one supper fast. That's a more gradual problem.

[MagmaRed370z]

Also take a look at this thread. "Might" be related to your issue as well.

Help ASAP

[ViCiouS]

Originally Posted by schellingr

Also take a look at this thread. "Might" be related to your issue as well.

Help ASAP

Very different seeming 'start' thanks though.



So turns out after sitting 3 days my new battery is dead... Looks like a have a voltage drain somewhere now too. Isn't there something about voltage stabilization at the fuel pump? I seem to recall reading that somewhere.

Tried jumping the car, it won't start. Also checked obd2, no CEL/DTCs..


Hoping to have time to check out fuel pressure and the pump this weekend.

[FairladyZ40th]

You've got a bad case of negative juju brotha... That's the problem ha. I'd have your alternator checked just to be sure also man.


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[ViCiouS]

Originally Posted by FairladyZ40th

You've got a bad case of negative juju brotha... That's the problem ha. I'd have your alternator checked just to be sure also man.

Haha, definitely some bad juju. At-least I have my parents g37 coupe to drive in the mean time (and swap parts to test).

Didn't have a battery issue the past 3 months since I got the new battery, it's just now dead, same time whatever this other problem started. sigh. Car runs over 14v though when running, so not the alternator.

[ViCiouS]

bump. finally getting this weekend to work on it. Any additional insights before starting to check things would be great. Starting with the battery and fuel pump.

[B&W_Evader]

Man, you've been down for a while now.