Hesitation problem above 2000 rpm

[300AZ]

Hello I became a z32 owner sometime this year and have been struggling with a hesitation issue since I got the car. If this is the wrong place to post I'm sorry I'm on mobile amd service prevents some stuff from loading..
My 90 n/a automatic will rev great when in park or neutral, but sometimes it will stall if the ac isn't on. and once the car is in drive from 2000-6000 rpm it will hesitate a lot the rpms will jump up and down and the CEL light will occasionally give a flash and click all the way up until 6k. The ecu isn't giving any codes, fuel pressure is good spark plugs have about a month on them but didn't help. I cleaned and put grease on every connection. I still haven't checked the maf or tps voltage but most people tell me it's the maf. I've searched and couldn't find any info on people showing the same symptoms as me any help would be appreciated

[PapaSmurf2k3]

Man that sounds crazy. Welcome to NICO!
I can't believe it isn't giving you any codes, even when it occasionally flashes the CEL.

I'd start by checking your engine grounds and shaking the harness in a few different places while the engine is running to see if you have some internal wire damage/connector damage. If it stumbles/idles up, you know you have an issue in that spot.

[300AZ]

I've tried what you said, found no difference but I also was able to check the volts on my maf which were good and the tps, when closed I believe it .455 k and when it was fully open it was about 3.85v which should be around 4-5v right?
I also checked the ohms on my coolant tempature plug and I got 1.3 ohms when fully warm but shouldn't it be around 0.8?

[PapaSmurf2k3]

Yeah, I don't think those are far off enough to cause too much of an issue though.
The fact that it isn't throwing a code has me thinking its the ECU...

[300AZ]

Well the idle issue I could fix some other time but what really has me stumped is the 2-6k hesitation and only when it's in drive 2 or 1.. I also forgot to mention Last time I checked i had 2 transmission codes revolution sensor and the fluid temperature sensor but i dont think those would make it hesitate right?

[PapaSmurf2k3]

Maybe fluid temp sensor? If it goes into a momentary limp mode...

[300AZ]

Update: the idle problem has to be a vacuum leak under the plenum, sounds like the lower plenum or a fuel injector, i did replace he pintle cap on the one that it's coming from so I'm not sure if it would be that.
No more transmission codes but I noticed my cas was fully counter clockwise which I'll check out tomorrow. Would the cas timing being off cause the hesitation?