Extinct, So.. you are saying I do not have a vacuum leak because it does not have a fault code for lean 02's. I have only a code of P0 505 which was decoded as " blocked Idle Air Control Valve" and sometimes, not always, another code would appear " Additive Adaptive Mixture Correction TRA Bank 1" and ".....Bank 2".
The idle would surge between 750 RPM to 1,000 RPM when siting at redlight intersections.
If I erase the P0 505 code with your Nanocom, how long will it take to come back assuming there is a real code problem. I need it not to come back for many hours in order to get smogged.
I tried to contact yo via email but noo-ne answered. I need a phone number of yours as well.
Thanks

 

Generally the D2 is hypersensitive to vacuum leaks at idle and will show up as a lean condition, at a minimum as persistent high LT fuel trims. Resetting the adaptive values means that the system relearns the fueling values, which takes some time. If it comes back after resetting then you definitely have a different condition.

Email is extinct@extinctmotorsports.com or you can use the contact us form on the website.

 

From the workshop manual......
---------------------------------------------------------------------------------------------
There are eight IACV diagnostic checks performed by the ECM:
l Output short circuit to earth – opening coil
l Output short circuit to battery supply – opening coil
l Output open circuit – opening coil
l Output short circuit to earth – closing coil
l Output short circuit to battery voltage – closing coil
l Output open circuit – closing coil
l Blocked IACV – rev/min error low (engine speed must be 100 rev/min less than the target speed, engine load
less than 2.5 and the measured air flow more than 10 kg/h less than the expected air flow for a fault condition to
be flagged).
l Blocked IACV – rev/min error high (the engine speed must be more than 180 rev/min greater than the target
speed and the measured air flow more than 10 kg/h greater than the expected air flow for a fault condition to be
flagged).


Should a malfunction of the component occur, the following fault codes may be evident and can be retrieved by
TestBook.
P Code J2012 Description Land Rover Description

P0505 Idle control system malfunction Blocked IACV - high or low rev/min error

--------------------------------------------------------------------------------------------------------------



Looks like it examines RPM AND air flow. I'd take a look at the MAF. Unplug it while the vehicle is running. What happens?

 

Extinct, please check your inbox and spam folder. I filled out the web site form, and I also sent an email about a week ago, but I did not hear back.

Where should be the starting point of a smoke test ? the air duct after the MAF location? one of the secure clip of the air filter top connecting to the MAF duct is missing but the location of the broken clip is in front the MAF.
The idle RPM surge comes at one point during spark plug fire order, and return to a little higher than normal idle RPM. One of the broken clip of the top air filter is on the short duct that houses the MAF, can the broken clip contribute to the problem? or one of the plug wire or plug is bad?

I dont have a lean code and I am not sure if I have a very small vacuum leak somewhere on the engine. I hope by resetting the adaptive value, it will compensate for the vacuum leak and not trigger the code?

 

TReK,
I did have to replace my old MAF with two more other good used OEM Bosch MAFs, one after another of course just to pick out the best one. I tested the engine using two different OEM IACVs but I still get the same P0505 which, in this case a high idle rather than low idle according to your manual instructions. I believe the IACVs are good. The high idle surges between 1000 RPM and 780 RPM. Can a small vacuum leak somewhere on the engine trigger this P0505, or I still have a problem with my good used OEM Bosch MAF??? The car runs fine and idle OK. The idle RPM surge comes at one point during spark plug fire order, and return to a little higher than normal idle RPM. One of the broken clip of the top air filter is on the short duct that houses the MAF, can the broken clip contribute to the problem? or one of the plug wire or plug is bad?

 

Yes, I would suspect the broken clip. And, IIRC, there is an oring in between the two sections of the tube between the air box and intake manifold.

 

The car has been sitting for a few days, and today the idle code P0505 is gone, but the original MAF code now comes back. My question is now what are the differences between a good used Bosch MAF and a brand new Bosch MAF? The car seems to run very well with the used MAF, but after 15 miles, it threw an error message " additive adaptive mixture correction TRA Bank 1 and 2 Drive Cycle A and B" which is a MAF error

Do I have a MAF issue or it just needs to be reset with a Nanocom. This used MAF has been on the car for the last 50 miles. I am not sure if the car ECU has learned to work well with the used MAF as yet.

Will it make any difference if I buy a brand new MAF? I dont know if it will.

Both the new and used MAFs will need to have adaptive value reset. I am not sure if Nanocom will reset the MAF. I need Extinct to tell me the answer to that.

 

[QUOTE=greenrovey;916640]Extinct, please check your inbox and spam folder. I filled out the web site form, and I also sent an email about a week ago, but I did not hear back.
/QUOTE]
Did not receive anything from you but have from other customers. You can send me an email through the forum though.

 

email sent. Thanks

 

A Bosch MAF was bought on Ebay for $63 including tax and will here next Tuesday. Meanwhile, a smoke test was done this morning and a small tiny smoke came out from the line connection to the intake manifold adjacent to the PVC nipple connection to the intake manifold.
The question - is this small vacuum leak enough to trigger the MAF code? ?The MAF code kept throwing itself out after 5 miles of driving. I am thinking maybe it has always been this MAF code that triggered the IACV code sometime? I need to get a new tubing grommet, where the smoke came out, to stop the vacuum leak. .