I recently installed the Powerlab 3/8" plenum spacer on my 03 350Z with 90,000 miles. The only other engine mod I have is a NISMO CAI. I done everything in the install correctly and it runs fine, except when its cold. When I'm slowing increasing the RPM's like when I'm in traffic, it feels like its wanting to sputter. Almost like I have bad gas but I know thats not the problem. I know since I have installed something that lets more air into the engine, that I'm running more of a lean mixture now. I was wondering if I need a tune up to equal out the greater amount of to the regular amount of fuel? Or does this little mod not affect the air/fuel mixture that much?

 

I would verify that with a air/fuel ratio check before making any assumptions.

 

I would also check your O2 sensors or if your throwing a code. One of those might be throwing your mixture off. have you seen your check engine light lately?

 

No, I haven't had any lights come on. I will watch how the car acts more closely to verify the issue.

 

keep us posted.

 

vac leak with the spacer install did you tighten the bolts in the correct order/tq them down correctly?, or check front strut bar make sure you have enough room there.

 

i have had my spacer on and off more than i can count..but i will say one time i was in a hurry getting it on,and i bolted the rubber ring around the oil cap under the spacer-knew something was wrong right after starting it-and i couldnt figure out why at first because of the engine cover.

 

My strut bar was resting on top of the manifold, but bought some spacers today and now its no longer touching. I tightend all the bolts exactly as it told me to. Well something different happened today. I started it up for the first time today and everything was fine. I drove it for maybe 10 min and let it sit when I parked it for about 10 min. When I came back out to start it and leave. It started fine, but after the RPM's went up after the start up, the RPM's dropped all the way back down and it died. I started it again and the RPM's still dropped very low and it almost died again, I gave it a tap of gas and it held it's normal RPM. This to me sounds like I'm taking into to much air and not enough fuel.

 

u should come to the cincy meet this weekend u are only like an hour from where it is going to be, i bet it is a vac leak! Mine did something like that when i put my spacer on, took it off and took stock gasket off then tightened everything the way it said in directions and have not had an issue since.

 

Erk, the wine'o thing IS funny! "You gotta wait!"...LOL!

 

i take no credit at all.. Mitch Hedberg RIP

 

Where do you mean? Cincinatti? I would go if I could, but I have to work all weekend. I have never even been to a show or meet or anything with my Z. Which spacer did you have? Explain again what you did to correct your problem. You put everything back to stock?