Hey guys. I just traded into a 93 2+2 NA, and it's having a kind of wierd issue - while the cruise is set the car will maintain speed, then drop back 3-5 mph, then a surge of power brings it back up to set speed (sometimes 3-5mph over set speed. Then the pattern repeats itself. There are also seemingly "dead spots" in the powerband and different throttle inputs yield different results. 1/4 throttle and the car seems to have no "pull" but any further into the throttle it picks up. The previous owner said that it needed new PCV valves - could bad PCV's be the issue? Thanks a lot guys. This is what the car looks like BTW.

 

Have you tried to just clean the MAF ? it's located in the air admitter
use any product WITHOUT NTPF
I had a similar problem and it's gone like that

 

It supposedly had a fairly new OEM MAF on it when I bought the car, but I suppose it's worth a shot.

 

I cleaned the MAF and it seemed to have eased the problem marginally. I also have a persistent high pitch whine while driving. It's loudest while accelerating and decelerating while in gear (which makes me think it might be transmission related). Here's a video I made of the noise... see what you guys think.
http://www.youtube.com/watch?v=Y9hDb...er_profilepage

 

Can you identify a general direction from which the sound is coming? Last time I heard a Z sound like that, it was because I installed the balance tube with a bracket between it and the plenum, which resulted in an air leak that whistled at certain RPM. If it's coming from the engine bay, look for an air leak...

 

It sounds more like a gear whine than a whistle. I'm going to try changing the transmission fluid and see if it clears up.

 

Z32 world recommends Redline MT-90 or MTL.

 

it also sounds like your timing belt needs replacement along with the bearings.

 

Thanks for the advice guys. I changed the trans fluid w/ mt90 and diff fluid while I was under there. I also bought a spare NA engine set w/ 120k miles. Gonna put that on the stand and save to do the 120k maintenance kit on it, then swap it out in place of my 200k motor that hasn't had a timing belt since 120k.