Serious Idle Problem

[SHIFT_SR20DET]

I own a 1990 240sx Hatch Back.

I blew my first engine in the car so I droped in another KA24E.

Now the problem im having is that when im coasting wheather the clutch is depressed in gear or in neutral w/ or w/o the clutch depressed the car idles nicely at 700rpm. Now as soon as i come to a stop the car idle increases to 2100rpm and just sits there. I have no Clue. Ive Posted on other boards. Ive Had my mechanic look at it ive tared apart the hole top end all valves tested good and all lines look good.

So whut im left with is a car that idles at 2100rpm and not a clue in how to fix it.

Oh just to add i had removed the A/C Compressor because it was broken so i dont know if that has anything to do with it but i have many friends that arnt running it either and are fine.

So im lost, and i need this fixed its startin to get to me driving with an idle over two grand for three months now.:bash:

PS If theres any speeling mistalkes or grammer mistakes please dont mind me i just finished workin a 65 hour week and its 130 am and im recked.

Thanks :bow:

[twitchy]

Hey, welcome to zilvia, I saw a post or 2 of yours in another site...

this will sound silly, and I just worked a 60 + hour week myself and its 2 am...

change your fuel filter.. Im not going to explain it now, but trust me, give it a shot. its like 10 bucks and you can do it with a screwdriver

if it doesnt fix the prob, well a clean fuel filter never hurts!

it worked for me

try it, If I remember i will explain tomorrow

[SHIFT_SR20DET]

Brand Spankin New 300ZX Fuel Filter Installed When I Installed Engine.

Another Thing to Add was the engine i got only had 20,000km on it.

Dont ask me how its a long story. But when i droped it in it never started and i found it was a gummed up injector on cylinder #2 so i just took one outta my old KA and installed it and boom fired up right away and ran great, well ran with this idle problem.

So in thinkin its a gumed up something orather.
Ive checked all the electrical ends.
Everything checks out acordif to the FSM.

But im thinkin if its a solenoid stuck or a valve stuck then ya?
I dunno this is really buggin me kuz it idles fine when im coasting.

Its gotta be some kinda sensor or switch or somethin.

Oh and My ECU is givin me the code of 55 which means everything's AOKAY :confused:

[SHIFT_SR20DET]

Anyone? :aw:

[Bill Roberts]

Simple stuff to check:

Full reset of ecu.
Vaccum hose slipped off.
Check all fuses inside and out.
Look for an air leak on the intake piping.
MAF sensor is sending a false reading (would not show up on the code)
Bad ground somewhere (hard to find)
ECU is misreading the speedo (again, full reset)

Anyone else?

[SHIFT_SR20DET]

Thanks guys, you know whut it was it was the TPS.

My car idles fine now but a bit rough.
I just changed the wires, plugs, cap and rotor.

Now whuts really boggling my mind is that ive lost all Pep.

Ususally when im for example in 2nd at 2800rpm and i mash the throttle i get neck snaping (figure of speach) pull, but now all i get is BRRRRRRRR and slowly increases the speed.

Now its one of two things Timing and/or the TPS Position.

Does anyone know how to Adjust them both properly.

Like ive done my timing enough times buy lettin it idle for 2 min, then disconecting the TPS Then setting it to 15 Degreese so i think im doin that right, but how do you properly adjust the TPS?

[SHIFT_SR20DET]

Thanks Guys, I Fixed It was the TPS.
I didn't know the TPS doubled as a Idler Switch which tells the computer that the throttle is closed and to Iniate Idle. :doh:

I was always adjusting it to the FSM Spec of Zero
Ohm's On the TPS but i guess on my car thats one mm
too much and told the computer that my throttle wasnt
closed and not to idle.
So i moved it that one mm and she's great.
Got my idle back, got my pep back and now i got my fuel economy back.


:wiggle: <---- Thats me right about now...
:stupid: