| It is with great pride and enthusiasm that I reintroduce my NA into the 2011 season. I have been tracking down a slight hesitation problem for almost 2 years and I finally got the problem fixed. Those of you who know me know the tenacity with which I've been trying to track this problem down. Late last year, with no other ideas and great reluctance, I decided the issue had be mechanical problems related to the engine heads. In January I started a massive in-car engine surgery basically to do a valve job. Today is really the third day that I'm able to drive the car since putting everything back together and I'm relieved to report back that I finally eliminated the hesitation issue! What a great feeling it is to have the Z back to 100%!! I'm struggling to contain myself and not spend all day driving around like a jacka$$ basking in the glory!! F-n AwEsOmE!!! I'll take a moment to try and explain the problem I was having and then get right to some pictures. The hesitation or stumble can best be described as the feeling you get when the A/C kicks on even though you know the A/C isn't running. If you know your engine well you can feel it's being robbed of power. This issue was most apparent at lower rpms (1,000-3,000) and would usually wash out above 3,000 rpm (or at least I couldn't perceive it above that speed). It wasn't effected by hot or cold engine temperatures. When going from a decel back to accel you were never sure if you'd return to 90% power, 95% power and fluctuating, or 100% power but it didn't happen only during turn-arounds it happened from a stop light too. It happened at full throttle and part throttle but not always, just sometimes (when it felt like it). This was unsettling if you're a person who's concerned about the driveability of the car especially in hard corners. What was frustrating was that almost no one could perceive the issue except me. People were thinking I was chasing a ghost saying things like, "Taylor, I think you should learn to live with it" and "Ummm, I - don't - feel - anything!" People thought I was full of it. Well now the problem's fixed and I can't be more proud of my decision to never let go. What was the root cause? Well I did the valve job as a last ditch effort. While in there I also replaced a very misaligned CAS (!) and deleted the EGR system. My machinist, Mike Rogers, noticed one #6 intake valve was slightly bent and fixed that. Which problem was responsible for the hesitation or stumble issue? I don't know! And I really don't care anymore! I can say that my gut says it was the #6 intake valve being slightly bent which made the whole engine system ever so slightly unpredictable. Lessons learned? Based on my belief that the problem was the #6 intake valve the ONLY way to recognize this was the compression test: #6 was slightly lower but well within the FSB tolerance. Therefore I believe the FSB differencial tolerance band, 14 psi difference between the highest and lowest compression number, is too large. If you do a compression test and your engine is on the ragged edge of 14 psi even if the vacuum test is ok, it's a sign! Take it seriously! It could be the reason your car isn't running smoothly, and more importantly it could be your ONLY indication if something mechanical is wrong! For those wondering how far a person will go to fix an NA check the follow-on tech post (and check out some cool video links) A big thanks goes to all those folks who've helped me contend with this and other Z issues over the last two years including Agner.S(CT), BiggTDogg, DVDBURN, BPC23, Greg(SpecialtyZ), Ash, Mike Rogers, flash-to-pass, BDE, Keith, Art S., Peter, Gordon of Witchhunter.com, Middletown Nissan (Dave and Scott), and others of CTZCC, you guys are great! Starting from the heads are off! Mandatory sitting in engine bay shot. Can't stand, engine is still there.
 Engine in car without the heads
 Passenger side block
 Driver side block
 All parts are stored here. Not the nicest setup but it works.
 Basement parts bin #1
 Basement parts bin #2
 Water pump shot by running straight water. Newbie idiot move! Don't ever do that again.
 NAPA coolant wash installed to reconcile idiot move above. Worked great! Next time install on the other heater core pipe -- better access.
 Passenger side head. Doesn't look anything unusual to me so I didn't even take a pick of the driver's side.
 Removing the EGR system is a celebration in itself!! SOoo much cleaner to work on now.
 You can look straight through the head. Who knew?
 Cleaned the corrosion off the knock sensor. Next time I'll solder on the wires!! And you should too.
 PITA head bolt.
 All important auto tensioner final measurement.
 Freeze frame engine being put together.
 
Fired up on the first pull and couldn't run better!!! Yeehaa!
Zarcasm(Hfd, CT)
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Intermittent Hesitation or Stumble Issue on 93NA Fixed! - 
