Hey guys,

this problem started not long time ago.

to give u an idea about the car, it's a 5AT modified with SC and built engine and couple of supporting mods.

"sometimes", when i start the car, put it on Drive or Reverse, the car won't accelerate past 1,250rpm, not even when i floor the pedal. When i put it on Neutral or Park, the car revs just fine... i also noticed when this condition happens, the AFR goes rich (for some odd reason).

sometimes, the car goes into this mode for a minute then poff, gone, then drives fine as if the issue wasn't even there.. sometimes it's like this for a whole day or 2.. sometimes it's a whole week or 2 without this issue.

Another thing i've noticed, when cranking, sometimes it starts the engine and throws "TCS OFF" CEL.. but that does is not link it to the issue directly.. i mean, when "TCS OFF" comes on it doesn't mean there won't be any acceleration. it might be related somehow, but it's not a direct cause.

This issue does not throw any codes (DTC), and when i took it to the dealership, they refused to work on it for 2 reasons.. 1 being it a modified car, 2 there are no DTCs.

any ideas? ppl with similar issue?

 

No DTC makes it tough to diagnose. Sounds like limp mode or a faulty throttle body.

 

Ebay tail lights?

 

I'm assuming you checked the electrical connections for the A/F sensors?

I would get the car up on a lift and check the wiring/sensor on the trans that registers what gear you are in. I would also just unplug the TB next time it happens, then plug it back in and see if that fixes it. I had a similar issue with my TB and it was just a bad connection, but the car stayed in limp mode all the time.

 

i swear to God above that hes not kidding..

OP, do you have NON NISSAN, non original tallights on your car?

 

that's the problem..!! a DTC would difinitely give me a hint where to look.
nope, and i've read about them.. unbelievably cheap!

That's an idea i'm gonna try. i will keep that in mind next time it happens.

Thanks
I'm aware of this issue.. and to answer your question, No, i don't have them..

i wish it was that easy to figure out really. but the whole car needs to be checked to eliminate the possibilities.

thanks for the input guys, any more ideas?

 

Try cutting pin101 to the ECU. This REALLY sounds like a throttle brake override issue especially since there's no codes indicating limp mode.

 

how can i do that?

 

https://my350z.com/forum/forced-indu...a-tt-350z.html

 

By supporting mods.....do you have an after market fuel system or fpr?

 

i'll go through that thread.. thanks

 

i have a walbro fuel pump, and an AAM stage 0 RFS. nothing else has been changed or modified on that system.

 

Update:

2 timing sensors and 1 throttle sensor (dunno which one) were replaced. the car is working fine now and hope it stays that way..

 

issue is back again... the sensors they replaced were cam sensors (left and right) + TPS (i think)..

any other ideas guys?