cegrover

Oooh...nice and subtle!

Hi all: I haven't started digging into this much yet, but searched and didn't find my exact symptoms. Here they are: 1) While driving along and with everything working fine, my tach will all of a sudden jump to much higher numbers and then move erratically. 2) At the same time that the tach act up, I'll notice some rough running - even at speed I can hear the car missing. Althought the engine starts running rough, it's obvious the tach readings are incorrect (jumping very quickly and reading 5000+ RPM when I'm in 4th gear at 50 MPH, for example). 3) If I come to a stop while this is happening, the idle is very rough and generally slow. 4) Here's the fun one: this can happen for a few minutes and then just stop and all will work great. Also, the last time it happened, I turned off the ignition, restarted and all was well (rebooted...). Details: Stock 1975 280Z with 186K miles which has bene sitting for a few years up until the last two months. My initial thoughts: Definitely electrical and something that can impact both the tach and the ignition. I think this must be a connection-type problem at the ignition control unit (ECU in modern terms, I suppose) or something else electrically 'global' like the voltage regulator or alternator. My plan: Check all obvious connections to these three major components, then go from there if I don't find something loose. Any thoughts or experience related to this? Does the tach get its reading via the control module? My car doesn't live at home, so I haven't had a chance to chase this down since it happend on Sunday; but I wanted to bounce this off the group...

So...I'm supposed to have back lighting in my '75? I just got it recently and noticed it was dark, but wasn't sure if it was supposed to light. I need to get the map light working anyway, so I'll check out that connection and bulb while I'm there...

Oops, can't edit this post? What I meant was chirping 2nd accidentally is a possibility with the '05 (not to mention easy burn outs when not accidental) and almost no chirping/spinning was possible with the '04! Okay, back to Zs...

The year of the Pathfinder explains it. I have a 2005 Xterra with 6-speed manual and VQ40 - chirping second is a problem with that combo! MY 2004 Xterra (3.3L with 5MT) didn't have that problem...