Z does not accelerate

thompsontechs

Just brainstorming here, old schools guys feel free to correct me, but that type of failure feels/sounds like maybe a sensor issue as in the car thinks you are braking hard and trying to accelerate at the same time... Like I said, just thinking out loud, does the ECU cut the gas if it reads you as on the brakes and accel at the same time??? If so, perhaps you have/had a sensor/switch checking out...

JT

MikeUCFL

Anyone know if one of those cheap elm327 OBD readers can read acceleration/brake positions? If so, you may be able to spot this using one. Otherwise, maybe cleaning out your MAF sensors with some CRC MAF cleaner could help?

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Magnetic Black Touring/Sport/Navi/6MT < Stillen G3 | ZSpeed Stage 1 Clutch/Flywheel/CMAK | RJM Rev 3.2 Pedal with Tilton Master

ZeN

Yes...obd2 elm327 with torque pro with paid Nissan Adv plugin theres brake switch parameter. It will let you know if your brake switch is on if its not. On off value only.

MikeUCFL

Ah, good to know

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Magnetic Black Touring/Sport/Navi/6MT < Stillen G3 | ZSpeed Stage 1 Clutch/Flywheel/CMAK | RJM Rev 3.2 Pedal with Tilton Master

thompsontechs

Be sure and let us kn ow when you get it figured out... nothing worse than having the same issue and not seeing an answer at the end.

P's_Z

Thanks. Ive experienced issues with dirty MAFs before, but usually the symptom is hesitation. No harm in trying this out though, as i have some CRC MAF cleaner around. 5 days of driving after the issue happened, no problems so far

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Zeta

chii370

sounds to me the fly by wire throttle is failing in some way. they can act several different ways when they fail from not responding at all to input, to reving up and down on their own to going full bore. just my opinion.

thompsontechs

This seems possible as well, perhaps a positioning sensor failure. The more stuff you have in the design, the more there is to fail. I do not like fly by wire stuff myself... give me a good old mechanical connection. Hey. I'm old!

juld0zer

2 switches near the brake pedal. disconnect the left one, then fit a jumper across the connector on the harness side (jumper the male connector, not the switch which you have now disabled)

nb: disconnect battery as it's very easy to accidentally short something while fitting the jumper.

jumper can be a big staple, wire or whatever. tape it up to insulate after

P's_Z

Sorry in advance for the question im about to do, but: how would this help and what possible risks am i looking at? Sorry, but never heard of doing this before.

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Zeta

juld0zer

cleaning the throttle bodies and performing the 3 relearns did not cure my random significant drop in throttle response. Like replacing all the VVT seals and o-rings, it cured a different annoying problem - sagging idle when stationary.
After cleaning and relearning, my idle throttle position is 0* according to my Scangauge 2 device. TPS voltage is about 0.55V according to Cipher. Before it would idle around 3*/0.6ish volts. So that tells me the throttle plate was probably held slightly open by carbon build up. So not a complete waste of effort. Glad to sign off on that one. I'll probably set myself a 1.5-2 year cleaning interval for the throttle bodies.

At this point, i have no choice but to delve deeper into the workings of the VVEL system to try and resolve this ongoing issue. With no local dealer support or technical experience, i am left to battle this alone. i might make a few phone calls to some Z workshops in the US to pick their brains

P's_Z

Sorry to hear that my friend

Keep us updated on this

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Zeta

Business Kat

Ya'll were right. It may be too early to call it but I think we solved it!!

Stillen makes a very high quality throttle position sensor extension that comes with their kit. The technology in this sensor is incredible. It's able to absorb heat and far beyond any cable I've ever come across.

Sarcasm aside, the sensor overheats and will start with false voltage readings and ultimately will cause the car to go into limp mode. This is why idle RPMs go wonky, random cuts in power will occur, and why the cars will go into limp mode.

Someone at Uprev had the same problems as me so they were able to fix it pretty easily. I can't believe this $40 cable and a $5 plastic elbow join cost me thousands in damages and repairs. Stillen told me the plastic peice wasn't covered under the warranty and when I contacted them about the TPS they said the warranty was only good for a year. Can't express how dissatisfied I am with Stillen.

I'll update again but I already can tell there's a massive difference driving it.

juld0zer

So a bodgy throttle body harness extender was the cause?

P's_Z

Thanks for writing. Yes, i was actually able to accelerate when this happened, just not too much.

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Zeta