My friends 2003 350Z Touring 6MT is having some hesitation issues while driving. The only mod he has is a AFE short ram intake w/ heat shield.


During the first 20 mins of driving the car hesistates under HARD ACCELERATION.

When you hit about 3000 RPMs the engine feels like its getting no gas/spark because it feels like you are getting half the power you should be.

This problem happens sporadically. It has no gear preference. Sometimes 1st, 2nd, and 3rd gears pull hard, and then you go into 4th and BAM, instant lag like you hit a wall. Sometimes it happens in 1st, sometimes in 2nd....


If the ambient temperature is above 40-45* then the problems are nonexistant.

We just changed out the spark plugs, so that is not the problem. There have been no CEL codes. No issues with idle. Swapped TB, that's working just fine.

TIA.

 

Happened to me before. It eventually cleared itself up, but I had it down to "bad gas".

You can try swapping coil packs and see if that changes anything.

Try just running the gas down to almost empty, then filling it up with the highest octane pump gas you have access to.

 

I don't know if this is relevant to the problem, but the cruise control is also not coming on. Its going into a failsafe mode where the set light just blinks instead of setting.

 

Also, the car has been doing this for the last few months now.

It runs fine after 20 mins, as if there was no problem to begin with. But until the car has been driven for at least 15 min, you get this same issue over and over.

 

Try disconnect the battery for 20-30 mins and reconnecting it.

 

have reset the ECU...

that didnt help

 

throttle position sensor?

 

Carbon build up on the inside of the throttle body? Not allowing the door to open up when you want it until it finally unsticks. Just a thought.

 

wen u step on it does the rpms go up and take a second for the acceleration kick in?

 

if thats the case ur clutch is slipping and your gonna eventually need to replace it...that happened to mine a few months ago and i got the ACT Stage 2 clutch lightweight flywheel and Stainless clutch lines...cost a little under a grand and its the best mod iv ever done, you can 100% feel the difference...plus if u replace it at the stealership theyll charge you something like 2400!!

 

no, its not the clutch.

Its not the TB. We swapped the TB into my car. Everything works fine.

Always use 91 octane which is the highest available here in Utah.


Keep in mind, if there was a problem with tranny it would get worse the hotter it gets. This problem seems to correct itself after 20 mins of normal driving. Just doesn't like the cold for some reason....which we can't figure out.

 

The cruise control not working and the near limp-mode status sounds similar to ECU voltage issues people were having when they installed ebay-quality aftermarket LED taillights.

 

Thanks for the heads up. He did change out the tail lights.

 

He changed his out with ANZO tail lights. I don't know the name, does that ring a bell??

 

There's your issue. You have ECU voltage issues. Put the stock tail lights back in.

 

Do the LED's draw too much current??

 

Something like that. There was discussion about installing resistors in-line with these aftermarket LED tails to combat the problem but I'm not sure how much was actually accomplished.

Other people have been able to swap out LED tails to other brands without issue- it seems to be isolated to specific aftermarket manufacturers, not aftermarket LED tails in general.

I would suggest just installing the OEM nissan LED tails so you will not have the risk of running into this problem again.

 

http://www.autopartswarehouse.com/de...W43b3f85c7ab9e

those are the tails he bought


This is not a cheap Ebay brand.... I did a search and couldn't find more info on what the actual problem was...too much draw or not enough The lights actually look really good on his black Z.

His OEMs broke.

 

Which thread of yours about the same subject would you like me to reply to, sir?

 

either or
haha
i'm lookin for resistor values

I found a few threads on the subject finally. Looks like some have soldered resistors.

I just don't know if the LED's have more or less resistance.