RPM/idle issue

[nyci30]

I have an infiniti i30, 1998, 168K miles.

My rpms were knocking up and down when i got the car, so i replaced my knock sensor (had codes for it, and the rest of the stuff too) i replaced 2 coils, 6 spark plugs (Champion, Double platniums) other coils seem fine. I had a miss fire, it went away, no more SES light. I replaced my intake manifold gasket, fuel injector gaskets (o rings), throttle body gasket. And that was about it for replaceing stuff (under the hood wise). I recently did the spark plugs, and all my issues decreased, what it started out as was, my rpms idleing (in park) at 1100, knocking down to 8-900, switch to drive, they went to 7-500 knocking down. I did the work on the car, and it went away. Before i did coil and 2 spark pkugs (i had 2 iridium, i only had 4 champion at the time), the car hesitated BADLY to accelerAte, at 1800-2100 it would spit, like a sprinkler and wouldnt speed up. At 1200-1700 in drive, it would jerk the whole car and accelerated poorly. Now, it dont do none of that, now, my issue is similar, it idles in park at 1000-1100, and in drive at 7-800 (no more knocking, once in a while, only in drive, not a major rpm drop). Dont jerk or spit like a sprinkler, smooth acceleration. SOMETIMES, rarely, itll show old symptoms, like if i stop at a light, i notice its idleing at 1000ish in drive, and i release the break, and it goes on its own & is able to change gears on its own. When i switch to park\drive, itll shoot up to 2000-2500rpms and stay their. I have to turn the car off to stop it.

What do you think can be causeing this? I lookd EVERYWHERE, no lights are on, i messed with the throttle cables and the black thing on the IACV, i cant lower my rpms anymore, its as tight as it can be, cables got slack (not excessive). I just am lost, please help me ASAP. thank you!


P.s, i took the egr gasket off and left it off, i had codes for the solenoid, map\baro sensor, missfire cyldiner 3, i removed the gasker for the EGR and it went away, the map/baro sensor dissapeared on its osn, thd missfire, i replaced the coil.

[nyci30]

UPDATE:

Forgot to include, imy EGR keeps geyting clogged by the entrance to the intske manifold, can that cause an issue? And i have a straight pipe set up, resonator delete & muffler delete, cat is still ibtact.

[NutriaforBreakfast]

The Floor Shop Manual says to check emissions items first
I have had the same issue as you-i think carbon is the problem
I cleaned out the tube from the EGR to the back of the intake plenum
as it was clogged
Put a new gasket on the tube
Spray electonic cleaner liberally in the actual EGR itself and
make sure the spring works in it by moving with your hand

Actually opened up the Idle Air Control Valve-there are some screws
that hold the cover and cleaned out the carbon (use electronic cleaner)
Took a rag and some cleaner to remove carbon from the throttle body
and throttle plate (spray cleaner on the rag not in the throttle body)

[nyci30]

My TB is clean, i used brake cleaner. Howd you get full access and sight to your EGR?i tried to take the sceews ofd my IACV, i couldnt i clean inside my manifold and it gets really clogged up sometimes. i canimagine the tube its self

[NutriaforBreakfast]

I used a can of carb cleaner and used the little straw that snugs into the
sprayer nozzle and got enough in the EGR valve at the bottom. I pushed
the diaphram of the EGR around a little to work the carb cleaner in it.

The IACV screws are on REALLY tight-be careful not the strip them.