I have read alot of the threads and there is by far more useful info on these forums than any of the others i have found online, so i became a member to get some help diagnosing my problem.

Anyway, I recently bought an 83 280ZX N/A coupe, 5 speed. I noticed a slight hesitation or surge (loss of power) while mildly accelerating. I notice the surging in the lower RPMs 1500-3000. And the most noticable loss of power is at 3400-3600 RPMs and it happens everytime i take her up to that range in the RPMs, regaurdless of engine temp or outside temp. I dont feel any surging beyond 4000 rpms but the overall power does not feel up to par. I dont seem to feel the surging if i floor it. It starts and idles fine.

Things i have checked/replaced:

new Plugs (ngks)
Checked plug wires (resistance is below 10000 ohms on all 6)
new Cap
new Rotor
new Fuel Filter
Checked and reset Ignition timing
All six injectors sound like they are working (consistent Ticking)
made sure all vaccuum lines are connected

I am going to replace the Pressure regulator next.

Any ideas or advice would be appreciated.

 

get an air/fuel gauge to make sure you're getting the right mixture @ those RPMs.

 

ok ya need to check one more thing on that mine does it too but its hit & miss
check yer AFM...

 

do a sweep on your tps, with a meeter, and check resistance just to make sure you are not geting a bad signal.

 

following my chilton on testing the TVS, I get continuity on the idle the two pins it says to check, But on the functional test, (where i loosen the screws and manually rotate the TVS with the enging running) I dont hear or feel any click. SHould I replace?

Also, how would I test/check the AFM?

 

I'm thinking you probably have some corrosion or wear on your AFM position sensor in those spots and it's sending a bad signal to the ECU.

See the sticky thread at the top of this forum.

https://www.zdriver.com/forum/showthread.php?t=14372

 

look for an exhaust leak also. The exhaust pipe on mine was cracked right after the"y" after the manifold, and with all the stock heat sheilds I couldn't hear or feel it.