Outer Limits 4x4 Board

I want to know how to get my car to idle properly and not fast. I've seen this question asked a number of times before on this forum but all seem to be regarding the carby'd version of the TB42 and not the EFI version.

My car is: 1994 Nissan Patrol, TB42E, Auto.

My situation is: when the engine is cold, even though i've rotated the throttle sensor so that the throttle is efectively on it's lowest setting, the engine still wants to warm up at approx. 1600-1800 rpm when in drive. When in neutral it's revving around 2000rpm. Thus when i'm at the traffic lights and in drive I really need to have full pressure on the brakes when the engine is cold. Otherwise the car will just surge forward. After the engine has warmed up the engine is revving around 1000rpm in drive and 1200rpm in neutral. If, when stopped and the engine has warmed up and i want it to idle at about 800rpm [bearing in mind the throttle sensor is at it's lowest setting] i need to put it in neutral and then go back into drive and the rev's will then drop.

What i've tried: I've had a look in the Haynes manual but it's not making sense to me.

Throttle Cable: tested it and the linkage is fine.

The book says 'the idle speed [idle screw] is set by turning an adjustment screw which is located next to the throttle lever'. This may be true on a carby by i can't see see such a screw on my EFI.

Auto Choke - the book tells me to refer to illustration 11.8. So i do. The illustration is again for a carby'd car and not EFI. I've looked for similar on my EFI but got no joy. The book also says to go to chapter 1. So i do. And i can't find a single thing on an auto choke in chapter 1.

Fast Idle Actuator - apparently my vehicle is meant to have one. The photo in the book is from a bird's eye view and looks like a little filter with an adjustment screw in the middle. But i can't see such a thing in my engine bay. Again i'm assuming it's only on a carby'd version.

Auxiliary Air Control [AAC] Valve - the book says my engine has this. I've had a look and it does! But i don't know what it does and whether or not this could be part of the problem?

Fast Idle Compensating Device [FICD] - the book also talks about this. It doesn't show me what it looks like but i've got a strong hunch it's the bit in front of the AAC Valve. Is my hunch correct? If so... could this be the cause of my problem? Are these repairable or do you just replace the whole thing??

Any suggestions please would be great. Also...
... would it be worth my while taking to the throttlebody with carby cleaner and a rag to clean any/all traces of carbon & debris? Or would this only loosen cr*p that'd only go into the TB and make things worse??

Thanks for your help.

In my Gregory's book there is a suppliment area at the back of the manual for the '94 onwards with the EFI info in it, actually I was looking at it last night.

Harvey, I've got a "Gregory's" manual number 509 (Patrol/Maverick petrol engines 1988-1997) which has the fuel injection supplement at the end of the book. It shows where different controls are positioned and descriptions of their purpose.
It says about idle speed and I quote from the book.

"The air regulator increases engine idle speed during engine warm up by allowing air to bypass the throttle valve. The air regulator is controlled by a bimetal strip which deflects gradually as it is heated by electrical current. As it deflects, the bimetal strip rotates a disc within the air regulator which decreases the air flow until it is completely closed.
The idle air adjusting (IAA) unit, which is mounted on the rear of the plenum chamber, controls engine idle speed, The IAA unit is comprised of the idle adjusting screw, the auxiliary air control (AAC) valve and the fast idle compensating device (FICD).
The (AAC) valve allows extra air to bypass the throttle valve, thereby maintaining the correct idle speed to compensate for extra loads placed upon the engine. The FICD operates in the same manner as the AAC valve but is used to compensate for the air conditioner load specifically.â€

i looked for additional manuals last night and came across a website called Pitstop Bookshop. They have an original Nissan Workshop Manual for $149AUD. Is that a fair price or is that waaaaaay to expensive? Is it worthwhile paying much more for the Nissan Manual vs. a Gregory's? Your thoughts would be great.

Also... thanks a bundle for writing from your gregory's below. It's a great help. Reading what you've written it appears that what i suspected to be the FICD probably is, and that both the FICD and the AAC valve are both attached to the IIA unit. Thus if i finger around the IIA i might just come across this idle adjustment screw that's hiding from me.

Thanks again.

Your Throttle Position Sensor is now out of whack. There should be procedure fro setting in manual. It doesn't control the idle anyway, but is crucial to kickdown in an auto. There is the small screw you mentioned for that. It will prob be on other side of throttle body to the TPS or with the throttle cam. It will only provide a stop for the butterfly. The idle speed is prob on the IAA you mentioned. Fast idle on efi is for when the ac is on to prevent stalling.

Your Throttle Position Sensor is now out of whack. There should be procedure fro setting in manual. It doesn't control the idle anyway, but is crucial to kickdown in an auto. There is the small screw you mentioned for that. It will prob be on other side of throttle body to the TPS or with the throttle cam. It will only provide a stop for the butterfly. The idle speed is prob on the IAA you mentioned. Fast idle on efi is for when the ac is on to prevent stalling.

stevelb1 wrote:In my Gregory's book there is a suppliment area at the back of the manual for the '94 onwards with the EFI info in it, actually I was looking at it last night.

watch Ebay
http://cgi.ebay.com.au/GQ-REPAIR-MANUAL ... dZViewItem

these were a bargain

harvey wrote:i looked for additional manuals last night and came across a website called Pitstop Bookshop. They have an original Nissan Workshop Manual for $149AUD. Is that a fair price or is that waaaaaay to expensive? Is it worthwhile paying much more for the Nissan Manual vs. a Gregory's? Your thoughts would be great.

Thats a good price, I tried to get one through Nissan and the deck jockey just laughed at me saying that they are not available and if they were they would be over the $900 to get all the books (that includes all the suppliments)

Theres a book shop in bankstown that whoely and solely deals in all books that are to do with cars including manuals, that might even be Pitstop that you mentioned, I bought from them earlier this year MQ manual included suppliment for about $210.

You only need the Standard (Generic) Manual and the Suppliment that is suited to your particular model