96 XJ6 with the 4.0,,Just bought this car a few months ago & have finally got it running, Now the problems I'm having is get all the sensors to reset so I can smog it, After taking it on 2 100 mile plus trips the scanner still shows red x on CAT,EVAP,AIR,EGR,, I believe CA allows the EVAP to be ignored,, Any suggestions ?

 

The EVAP valve can be tested by feeling for clicking with a 9 volt battery

It is located below the air filter

I had a vac hose missing on this

When you start the car it should be closed and after about 60 seconds it should click open

The ECR can be cleaned of carbon buildup not allowing it to seal

There is a position sensor inside the valve and it will read 0.70 volts dc on the Red / Pink color wire on engine start up , The valve should be closed on engine start up

This will be the center wire on the EGR connector at the EGR valve

The Cats / O2 sensor connectors can get some corrosion that can be cleaned

Remove only one at a time as they can be swapped as the connectors are identical

4 sensors on your model , 2 / 4 wire black connectors on th right side by the shock stud mount and the same looking aft of the rear edge of the valve cover

There is a fuse and relay on the secondary air injection pump that has gone through a couple of TSBs

" The AIR pump operates for a short period of time following every engine start. It typically operates for approximately 10-20 seconds at normal operating temperatures, then switches off for approximately 5-10 seconds, and then restarts to allow the system diagnostic check to occur."

Place your finger on the secondary air injection relay to feel it clicking as well as the smog pump for rumble

05.1-27 Amended (jagrepair.com)

# 7 / 25 amp right engine bay fuse box , this fuse has been uprated to 30 amp by a TSB

05.1-30 (jagrepair.com)

 

Well I'm pretty sure the MAF is bad, Drove for 2 hrs & never got a reading, It stayed at 0.00, Did the unplug test & the idle never changed, According to Orielly's, Napa & RockAuto theres none in the United States, Going to try You Pull It tomorrow

 

There is an error on the software reading the MAF that you would have to multiply by a factor of 10 or 100

At idle it should read a little over 4.0 grams / second

there are 2 part #s for the NAF and you need the only one for the normally aspirated

 

Is it possible to have a bad ECM with no Check Eng light? Because now I have CAT,EVAP,AIR,EGR,HRT that won't reset, I have to wait until Monday to find out if I can get a used MAF.

 

Before you run off for a MAF,there are some things to check to ensure you have power on the ECU , MAF , and no CEL light

Editing

2nd power to the MAF comes from the large ECU Controlled Relay in the form of battery B + voltage ( this power is used at all times )

it is controlled by the ECU and brings power back into the MAF , ECU , fuel injectors , and 4 engine regulation sensors

1st power to the ECU is the ignition positive relay in the corner of the right engine bay fuse box ( King Relay ) , this is point 32 double hash circle of the pic below

This will be fuse # 12 / 10 amp in the right engine bay fuse box

in all the fuse boxes fuse # 10 , 12 , 14 , 16 rely on the relay in the corner of the fuse box to close , King relay

all the rest of the fuses are hot at all times and bypass the king relays as wired inside the fuse boxes

instrument power is from a couple of fuses in the left heelboard fuse box ( powered by the closing of the relay in the fuse box referred to as the 2nd ignition positive relay ) ,this is another King relay

To test these King and ECU controlled relays have the key in the run postion and remove them and they should click back to the open , relaxed position

If the relays click they are getting the correct command but the power contacts inside can be burnt and compromised to be able to run their devices properly

 

I'm back so will be adding to above

 

Just did a test of the maf

Key on Maf unplugged Testing plug side 0.00 volts

Eng running unplugged, Testing plug side 0.00 volts

Running cold idle,Connected 1.52 volts keep dropping as eng warmed up

High rpm ( my guess probably 3000 rpm) climbed to 3.00 volts

Scanner on OBD2 connector has 0.00 input

 

Did you ever get a MAF engine code ?

The MAF needs to be plugged in connected as a functioning sensor

With the MAF still plugged in the MAF is feed 12 volts or B + being around 13.5 volts with the alternator turning on the Blacl Light Green color wire

You have a ground wire color Pink / Slate ( gray ) so it will read o volts

The Green / Pink color wire ( middle wire ) is the return to the ECU with the 1.2 volts DC at idle going to around 5.0 with throttle up

There was a chart of the MAF voltage values vs. some variable I will have to find

There is a TSB on not running the engine up too high without moving and probably has to do with transmission cooling

 

See this link

MAF Question - Jaguar Forums - Jaguar Enthusiasts Forum

and

Sourcing a Mass Airflow sensor - Jaguar Forums - Jaguar Enthusiasts Forum

As an engineering rule of thumb, the mass air flow should be in the range of 1.0 grams / second at 600 RPM per liter of displacement

So your idle is higher than that so 4.5 grams / second

 

"Did you ever get a MAF engine code ?" NO, Only code I've ever gotten is "Random Misfire"

"So your idle is higher than that so 4.5 grams / second" , Came down as eng warmed

I'm trying to read previous wiring diagram you posted but wife moved magnifiying glass,But it looks like wire BLG circuit has control of MAF,EGR, EVAP PLUS INJECTORS ?,,, Would I test that circuit to ground to see iF wires good

​​​​​​​The HRT sensors finally went green

 

I you follow the red marked lines the ECU controlled Relay gives it B +

This would include the fuel injectors which are running

You can swap the large ECU Controlled Relay with a headlight or one of the same part # , there are several the same part #

The ECU connector on the ECU can have a bad socket # Red 4 for the Green / Pink return signal wire

look for a 2 flap pinching socket that is missing one of the flaps to not be able to give pin grip

 

I'm not sure what you trying to show me with the diagram

 

Swapped relays still nothing

 

which diagram ?

the ECU controlled relay that passes power through is battery cable B + at point 104 square on the far-left top side

the connector veiw is looking into the wire side connector halves of the ECU

 

Looks like pins 17 & 24 are the ones bringing inputs to the ECM, So I figure my next step is to see if I got power to the ECM on those circuits or do I have broken wire somewhere, But i'm wondering how do I go about doing that

 

Since you have the fuel injectors working somewhat maybe 100 % , if you put a meter on the 2nd power into the ECU at socket Red 17 and Black 24 you will most likely see B + volts

A compromised connection/ relay power contact will trade voltage for current as a dynamic functioning circuit with power running through the veins

This leaves swapping the large ECU Controlled relay on the premise that the internal power contacts are compromised / burnt limiting the current passing through to your devices like the MAF and others which includes your injectors

If you remove the ECU connectors the ECU Controlled relay will not be able to be commanded closed

On my ECU Controlled relay socket wires coming out from underneath the wires were nicked as they were messing around with the previous owner

 

The splice to target would be the one below the pointing finger ( this will be a group of 3 or 4 splices as the wires will not fit in a single splice , this keep the wire bundle thinner and not thick and bulky )

The 2nd splice would be on the EVAP valve under the air filter which may run that OK but not the MAF

Your MAF return signal seems to be in range at 3 volts at 3000 RPM just not seen by the ECU properly

 

Are you sure the splice for MAF and EVAP are under the air filter , The wires just seem to run off in far different directions

 

So this wire appears to be the same wire coming off the Maf, Couldn't I scrape off a little insulation and take a reading up on the firewall ? because after that point it looks like the bundle goes thru fire wall to ECM, If I get voltage there then It seems to me the ECM connector would be next to check.