HELP! newbie 300zx problems.

[Ricardosaurusrex]

greetings!

so ive been having some small issues with my Z. the first one being the infamous lag or lack of power. so far ive tried most of the things that are recommended. (change fuel filter, new plugs, clean maf, new air filters) so far no luck. the second thing its been doing is RPMS go way down when i brake abruptly. ive been reading alot of the forums on here before i asked this question and even read the guide of how to fix lag from TT.net. but unfortunately this has not helped. would anyone have a better starting point for me? i really hate the lack of power on my z and the car dying when i brake abruptly.

Thanks for all your help guys, really awesome forum

[DCaff300ZX]

My thoughts not related to any particular site or thread would be to check ALL of your electrical connectors at your PTU, idle circuit (IACV/PCV/all vacuum hoses) and timing (CAS) for lag/lack of power issues beyond what you say you've done there.
Have you checked your brake boost for vacuum loss at the diaphragm? Also, I recently learned there is a clutch booster as well with the same diaphragm booster and vacuum hoses to check as well, looking for vacuum leaks which will rob your response and power and maybe even cause your rpm drop at braking.

[Ricardosaurusrex]

thanks, for the quick response, i will check the brake boost tomorrow. as for the clutch, i forgot to mention its an automatic transmission. would that make any difference in what to check first?

Thanks

[Ricardosaurusrex]

Hi, thanks for the response. so i switched out my pcv valves and the hoses (both hoses clogged to heck and valves in the closed position) and now its not lagging during take off..... most of the time i would say like 90% of the time. however, there are a few times when i do notice it just holds untill i reach say 3k rpms to gain any sensible speed. what should i change next? im at a bit of a loss here. not quite sure what could be causing that lack of power 10% of the time.

[ThisIsSparTTa]

The FSM has a whole section to check out for different types of hesitations. Also TT.net has some FAQs on it, I think. I'm too lazy to link them right now.

[Ricardosaurusrex]

Thanks for the references. It's more than what I had before. I'll keep looking, thanks again
:-)

[Oh Em Zee]

http://www.twinturbo.net/nissan/300zx/f ... tate2.html

[Ricardosaurusrex]

Sweet! This is exactly what I was looking for. Thanks, I'll tackle this list on Friday :-)

[DCaff300ZX]

Here's the OFSM that ThisIsSparta mentioned, you will want the EF-EC section with all of the diagnosis and tests for the various fuel delivery issues:
http://300zx-twinturbo.com/cgi-bin/manual.cgi

[Ricardosaurusrex]

Thanks, I have this bookmarked cept I didn't know where to look. This helps a lot. Thanks for the reply I'll look this section over tomorrow at work

[DCaff300ZX]

I've been in that section just recently working on a idle problem so I'll keep an eye on your thread and try and help out if I can.
Good Luck!