Now you got me fired up to look into my own rougher when warmed up engine at idle, cooler weather makes me more likely to wrench on it and see if I can find my problem.

here I demo the color tune. now I am not saying this is the issue you have just something to consider if you have a misfire.

 

i did find inject #6 dead.  it was shorted and never sprayed any fuel.  and to ur point, when i unplugged harness on #6 it made no diff on engine.  removing harness on injectors 5,4,3 & 2 made some diff.  unplugging harness on #1 made a huge diff.  engine was shaking pretty bad

replacing inj#6 didn't make it run any better though.  so i moved on to checking the valves and noticed several exhaust and intake ones extremely tight.  The service manual indicated diff values on diff pages.  for example, on one page it said .008 & .010 when hot.  then few pages its said .010 & .012 when hot

i went with 10 & 12 since they were really tight.  i think i was barely able to fit a .007 feeler.

doing the above put the vaccum gauge from lower 14 to upper 21 or 22

 

2 minutes ago, ira said:

i did find inject #6 dead.  it was shorted and never sprayed any fuel.  and to ur point, when i unplugged harness on #6 it made no diff on engine.  removing harness on injectors 5,4,3 & 2 made some diff.  unplugging harness on #1 made a huge diff.  engine was shaking pretty bad

replacing inj#6 didn't make it run any better though.  so i moved on to checking the valves and noticed several exhaust and intake ones extremely tight.  The service manual indicated diff values on diff pages.  for example, on one page it said .008 & .010 when hot.  then few pages its said .010 & .012 when hot

i went with 10 & 12 since they were really tight.  i think i was barely able to fit a .007 feeler.

doing the above put the vaccum gauge from lower 14 to upper 21 or 22

 

so after all the above it runs fine but for hot idle, which can be fixed by lifting the cap, is that right?

Correct.  

i have not been able to do road test due to rain.  but will find a way to keep the cap raised and take it for a spin.

I've had this car since 2005, it currently has 87k miles.  when i moved out of MN i could not take it right away.  it sat for few years.  however even back then it started to have a wacko behavior.  one day it will rip the road apart and next hour or so i cant go passed 30miles.  if i hit gas to boost it would choke, and feel like its taking a nose dive and jitter a lot.  if i tried to accelerate slowly, it did the same thing as well.  

3 weeks ago a friend of mine was coming to east cost to pick up a car from auction.  So he brought my Z to the east cost.

 

What brand is the cap & rotor currently on the distributor?   Yec, Standard Motor Products etc....

What is the build date of your ZX?  The 1st year turbo's used a different rotor, after Jan of 82 the rotor changed.  Make sure you have the correct rotor, the cap is the same for all turbo motors.

Edited November 2, 20204 yr by S30Driver
addition

as you can see, diff values for valve adj in the same manual

 

 

hard to tell the brand.  most likely purchased from NAPA

 

Rotor said made in Italy.  it has letter F and the numbers 961.

 

cap has #22162-D8000.  did a google search but nothing useful

 

what do you guys recommend?

I had good luck with YEC brand cap & rotor on the 3 turbo cars I have owned.  Japanese brands are always preferred.

Read my previous post again about the rotor change in 82....

For the valve clearance, I would go with .008 .010 for the cold setting if you have the solid lifter head.

On the pass side of the head, near the #2 plug, does it say P90  or  P90A ?

@S30Driver Just curious. Do you know what the difference was in the 1st and 2nd year turbo distributors? If the caps were the same I'm assuming the change was either the dist. shaft diameter or the height or both.

p90A