does it blow alot of black smoke under 3000rpm? i'm not running any IAA, ACC, air regulator or PR solenoid, i had to raise the grub screw to get it to idle, i'm still running stocko computer, they only raise and adjust idle for Air Con.
what is it like to start?
with the TPS, or idle switch? at idle, no throttle should be continuity, as soon as you move the throttle should be no continuity. by testing the top 2 pins on the TPS.

i dont know if this is any help or not but i have repaired 3 nissan silvias (on seperate occasions) all shering the same symtoms you describe on all 3 it turned out to be the air flow meter they still read within parameters so no fault diagnosis detected but are unaccurately metering the air.
if you can find someone with an afm plug in and see if there is a change.
hope this is of help!

I was reading that , need to go through it a bit moe . there is no way you would be able to get the engine to run at 250 rpm so it loses me a bit . 250 rpm above idle would work .
Since I can not get this thing to idle , setting the tps this way is not going to happen .

See what it runs like in the weekend and read the manula again on set up and see what I have missed .

Chris

you set the TPS using revs alone. not resistance.

The ECU test light (in a specific test mode) will light when the off-idle circuit is in action.

I still think it's TPS.

Ok cleaned out IACV and ACC valves they were ok .
I checked the throttle sensor and it was not bad . Decided to see what it was like when it warmed up , so sat there reving the snot out of it to keep it about 3000 rmp etc . Once warm was a bit better , checked temp sensor hot .5 ohms . Will check book but think thats right . So tweeked the throttle position to see what I could get out of it and got it to 0.997 ( was 1.087) seems to run a bit better . Its almost driveable now .

I have to wind in a bit of throttle to get it to idle so I am thinking I might try and back out some more throttle position sensor and see if it gets better .

It also runs noticibly better with no 3 injector disconented compared to the others . may be a bit crook ( but leak checked ok ) .

Anyway will take it out for a thrash in the weekend and see how it goes and tweak from there . thanks for the advice .

Chris

Well there is two ways of looking at it . the computer has a bunch of fail safe modes in it , oxy sensor , airflow meter etc . When parameters get out of limits it fails back to fail safe mode , ie no revs above 2000 rpm .

If you pull the plug on the oxy sensor it should go to fail safe mode , if the sensor wa faulty it should run ok abit restricted . Dito on the air flow meter . I have had the engine running fine in the past without the airflow meter .

Now oxygen sensors only work when they are warm , hence some are heated . the ca18de I have is not heated ( turbo ones are ) . There is no way the sensor gets hot enough at start up to get a good reading , thus it should be running without it . I belive the computer ignores oxy until off idle and at full throttle etc .

I doubt the sensor could cause such a change in the mixture to cause it not too run . Have a few vehicles here running them disconeccted ( not ca18de's thou ) and they run fine , economy may be out the window but run ok .
This will not idle , I can only keep it running by keeping it above 3000rpm . Let it drop and it goes to crap , backfires etc etc .

So off to the shed to pull the AAC and IACV and clean them and try again

Cheers

Chris

Quote:

wouldn;t that mean that the 02 sensor is rooted - as in, replace it?

Had not thought of the FPR leaking into the intake but I have swapped it out for another one incase it was to high pressure causing over fueling .IE not getting the vacum to low pressure . Just the same .

Cheers

Ok as edited below runs just the same with the oxy plug off as before .

A leaky injector was my first though so pull the fuel rail off etc , they are not leaking without the engine running . just the fuel pump pressure etc .

I have only just moved the tps of late and since it ohms ok I doubt its the culprit , but will set it back up to the book tomorrow , since I have moved it etc .

It could well have a blocked IAC or IACV but could the affect it this much , trhey just port air , thus to a certain point should be corrected for by the air flow meter . I could close of the IACV in another car and the idle would drop etc but never run like this . Still I will pull them out and check them also .
Post results tomorrow .

Cheers

Chris

check the fuel pressure regulator, sometimes the diaphragm splits and suck fuel directly into the intake manifold.