Does anyone have an illustration for the breather hoses,in particular the section that runs from the intake duct to the oil filler tube. Also some part numbers would help. I'm trying to order a new hose and not sure if it's the right one. It's listed as a breather element hose.

 

Please remind us of the year, model and engine of your Jaguar so we can give you an accurate reply. It's a great idea to add that info to your signature line so others don't have to ask.

Cheers,

Don

 

Sorry,it's a 1988 Vanden Plas with the 3.6L engine.

 

Hello,
May be that this link may be useful

Water Rail and Heater Return Hose-3.2/3.6/4.0 Litre - Parts For XJ6 (2.9, 3.2, 3.6, 4.0) from (V)500001 to (V)667828 | Jaguar Classic Parts UK

cordially

 

Hi frenchfairplaydriver,

Thank you for your kind attempt to help 95Leaper, but that's the link to the water rail heater hoses. If I understand his question, he's looking for a crankcase breather hose, either Part 4 or Part 6 in the diagram below. The breather heating element is Part 5.



95Leaper, you can look up the part numbers at jaguarclassicparts.com:

Engine Breathing-3.2/3.6/4.0 Litre - Parts For XJ6 (2.9, 3.2, 3.6, 4.0) from (V)500001 to (V)667828 | Jaguar Classic Parts UK

You can check for the most recent supersession part numbers and discounted Jaguar dealer prices at jaguarmerriamparts.com and gaudinjaguarparts.com.

You can also check with our forum sponsors SNG Barratt, Coventry West and Jagbits for competitive pricing.

Cheers,

Don

 

Thanks guys! It's actually #6 element to restrictor hose that I need. Mine has a large crack across the bottom inside the curve. I'll be ordering this today. Thanks again!

 

Hey Guys.

I have a 89 xj6 3.6.

i am having a problem getting the idle dialed in.
i have everything setup to spec, she just idles way to high.

my question is, is there a second air restrictor that is not shown in the diagram?

i think this could be my problem because if i pinch off the hose that goes from the oil fill tube to the intake elbow i can stall the engine. leading me to believe to much airflow.

 

Hi Joel,

Too much unmetered airflow may very well be the cause of your high idle, but it is unlikely that it has anything to do with the restrictor. The crankcase breathing system does not use a PCV valve but is instead designed to maintain a slight vacuum in the crankcase at all engine speeds by the sizing of the orifices. You can read about its operation in the Crankcase Emission Control section of the manual at the link below:

AJ6 Engine Management System Diagnostic Guide

The most common causes of high idle are a leak in the air intake plumbing somewhere between the MAF sensor and the intake manifold gasket; a leak in a crankcase breather hose or vacuum hose; a stuck-open EGR valve or carbon canister purge valve; a problem with the Idle Air Control Valve, typically carbon buildup that prevents the stepper motor pintle from closing completely; the throttle butterfly valve not closing to spec due to varnish/gunk buildup on the back side of the plate; or a sticking throttle cable or weak throttle return spring.

Have you checked the Vehicle Condition Monitor for any stored diagnostic trouble codes that may point you in the right direction? To check, turn the key to position II (Ignition ON) but do not start the engine. Press and release the VCM button on the trip computer to the right of the steering wheel and watch for a message to appear in the mileage display/odometer below the speedometer. Codes are displayed in the form of "FF" or "Fuel Fault" plus a number.

If you find a code, report it here and we'll try to help.

Cheers,

Don

 

Hey Don,

Thanks for the info. I do belive my problem is with the intake control orfice i say that because, if i pintch the breather hose i can stall the engine.

i do get a engine DTC after warm up. FF 4 (FULL RICH) I think i am receiving this DTC because of the loss of vacume at the control orfice.

what i have done up to this point is.
replaced breather hoses.
Verified breather restrictor
adjusted throttle body to .002 Spec
verified there are no vacume leaks
Adjusted TPS 0.300 Volts
Verifed 02 Sensor power and reference
Cleaned AAV
Cleaned and verified IAC operation
New plugs wires rotor and cap
new coil
Verified ignition balast

Does this sound like i am on the right track??


i am not sure i understand how the control orfice works. Is there moving parts inside, is there a thermal valve inside??

 

I'm not sure what you are calling the "intake control orifice," but previously you said you were able to stall the engine by pinching the hose that goes from the oil fill tube to the intake elbow. This may cause a buildup of excess pressure in the crankcase, but I can't see why the loss of the relatively small amount of air/vapor flow into the intake would cause the engine to stall.

There are two restrictors in the system. One is part 10 in the diagram I posted earlier, which is a simple stepped washer or metal ferrule with no moving parts. The other is the coolant-heated restrictor which is the part labeled "Refer to Engine." As far as I can recall, it has no moving parts. Inside it has an air passage from the manifold to the hose fitting, and a water jacket for coolant flow between the two coolant hose fittings.

If the engine is running rich, then it seems unlikely that you have a problem with excessive air. But FF4 means the O2S is indicating full rich fueling...if there is a problem with the O2S the engine may not actually be running rich. How did you confirm the O2S is operating properly?

Where did you get this specification and how did you measure it?

Cheers,

Don

 

Hi Don.

The Part That i referred to as the control orifice is the part that says refer to engine.

You are right about stalling the engine by pinching the hose to the filler tube that is most likely not possible.. I made a mistake when explaining my self.

The hose I was refering to is the one that branches off to the part that says refer to engine.. I am aware that when I pinch this hose and cause the engine to stall, this is Due to the Base Idle Being set way to low in turn removing the needed air for combustion.

Now that brings me back to my primary problem. I can not get the base idle close to where i needs to be, so the car idles at about 1200-1300 and lacks power, and scavenges oil because there is too much vacuum in the breather assembly.

 

Regarding The Restrictors in the system. Both Seem to be doing what restrictors do, But the coolant heated restrictor has a **** ton of vacuum volume passing through it. No doubt this is my high idle problem.

I understand that i can balance this volume of air by adjusting the air gape of the throttle body butterfly. right now the butterfly is open .002 and the TPS is set to idle.

Specs. I get my specs from the Haynes Manual and ALLData.


For the O2 I Checked Reference voltage, Output Signal and Heater Power, Resistance and Ground. All are in spec.

I would write the specs out but dont have them with me at the moment.

 

Sorry if my brain is tired, but I don't understand what you mean by "...the TPS is set to idle." If I recall correctly, with the key in position II (ON) but the engine not running, the TPS supply voltage should be about 5.0V, and the TPS output voltage (measured by back-probing the electrical connector) should vary from just above 0V to just below 5V.

Haynes is generally reliable. In my experience ALLData is less so. I find they don't always provide the correct information for a given model year. The best references are the Jaguar Workshop Manual and various other Jaguar service documents, and the Technical Service Bulletins (TSBs) issued by Jaguar over the years. Much of this documentation is available free at sites like jagrepair.com. The Workshop Manual has been available on DVD from the Jaguar Daimler Heritage Trust (jaguarheritage.com) but the last time I checked they were selling off their existing inventory.

The O2S output voltage should swing high and low. Off the top of my head, I think it's in the same range as the TPS - a little above 0V to a little under 5V. If the voltage doesn't swing, the sensor is stuck and should be replaced.

One thought just occurred to me: on the early XJ40s there may have been an idle adjustment screw on the MAF sensor. If your car has the screw, I would recommend marking it so you can return it to its current position if necessary.

One other thought: You have simultaneous rich running and high idle. It would be worth pulling the vacuum hose off of the fuel pressure regulator and checking for signs of wet fuel which indicates failure of the diaphragm. This allows raw, unmetered fuel to be inhaled directly into the intake manifold, leading to rich running the ECM may not be able to correct.

Cheers,

Don

 

1989 xj6 3.6L

I can not get the idle down to a reasonable level. 700 - 800 rpm


throttle is set at .002

TPS is at .300 volt

when i Pinch off the breather hose i can manipulate the idle and even stall the engine.

i have also checked for secondary fuel.

what is going on??

 

Hi Joel. I just went through this with mine. Look at my thread "ff39 cured now high idle" . I think it may point you the right way. I got a lot of excellent advice there. Good luck

 

Hey Jerry

its not my IACM

 

Hi Joel,

I have merged your new thread with your old thread because it becomes very confusing to have the same issue discussed in multiple threads. I've also re-titled the thread to reflect the nature of your issue.

I'm still not certain I understand how you calibrated your TPS. Can you please explain?

Have you rechecked the O2S to confirm its output voltage is swinging properly?

How did you confirm the proper operation of the IACV?

Did you check to see if your MAF has an idle adjustment screw? If so, I believe there's a calibration procedure in the Workshop Manual.

Cheers,

Don

 

hey,

I calibrated The TPS by using a volt meter on the siginal out put if the tps sensor. (green wire on my car) currently i have my tps at about .300 volts.

The O2 Sensor I did previously check, I was putting out an Oscillating voltage, at this moment I am not sure what the reading was as it has been a few days since i have done that but i do intend to check again due to the recurring FF4.

I confirmed the IACV by checking reference voltage and visual operation, I also electrically manipulate it to change the runnability of the car at idle by using a jumper on the connection.

Where Is this workshop manual that you speak of? is that the document you linked earlier in the thread??

 

In regards to the correct procedure for setting the base idle here it is for future reference which comes courtesy of AJ6 FAULT CODES AND IDLE SETTING / AJ6 Engineering

I suggest those that who are not familiar with it's location locate the air bypass adjustment screw which is very near to the stepper motor (IACV) within the same housing. It's adjusted using the appropriate size allen key. It's also very often loose so first thing to do is unscrew it and wrap some teflon tape around the thread to help keep it in position

[/IMG]

IDLE STEPPER MOTOR SETTING PROCEDURE 3.6 Litre


You will need a 5w 100ohm resistor for this process which is available from any electronics store.



-set TPS to 0.32 volts at closed throttle
-set throttle butterfly to 0.05mm or 0.002"

1. Run engine until fully warm.
2. Switch off and remove connector from coolant sensor.
3. Insert 100 ohm resistor across coolant connector terminals.
4. Switch on ignition and after 10 seconds remove connector from stepper motor (which will now be fully seated and closing off idle orifice).
5. Switch off ignition, remove 100 ohm resistor and reconnect coolant sensor.
6. Start engine and set base idle speed to 600 r.p.m. via air bypass adjustment screw near to stepper motor.
7. Reconnect stepper motor - idle should now stabilize around 700 r.p.m.
8. Your done - enjoy your smoother performing engine!

For those with a proper way of diagnosing emissions:

1. Check idle CO2 - factory setting quoted as 1-2% but we find that most engines idle best with a weak setting around 1% or even slightly less depending on HC emission being stable. This is can be done via the set screw hidden away on top of the MAF

3.2 & 4.0 Litre


-set TPS to 0.6 volts at closed throttle
-set throttle butterfly to 0.05mm or 0.002"

1. Run engine until fully warm.
2. Switch off ignition.
3. After 5 seconds switch on ignition - wait 5 seconds - remove connector from stepper motor.
4. Switch off ignition.
5. Wait 15 seconds then replace connector on stepper motor.
6. Repeat operation sequence 3 - 5 twice - on the last occasion do not reconnect stepper motor.
7. Start engine and set base idle to 550 - 600 r.p.m. via air bypass adjuster.
8. Switch ignition off and reconnect idle stepper motor.
9. Restart engine - idle speed should now stabilise around speed shown below.
10. Your done - enjoy your smoother performing engine!
11. Check idle CO as for 3.6 (if non-cat).

Specified Idle Speeds

Cold in neutral - 800 (Auto)
Hot in neutral - 700 (Auto)
Cold in drive - 650 (Auto)
Hot in drive - 580 (Auto) (3.2L = 650)
Hot in Neutral - 800 (Manual)


Note: Cold idle speeds will be slightly higher at very low temperatures.
If the above procedures do not result in stable idling check that the throttle potentiometer is correctly set. Whilst the ECU will automatically compensate for minor errors within the range of the adaptive memory, a badly adjusted throttle potentiometer can cause spurious drive-ability and idling problems.



- don't forget to reset your trip computer to check future fuel
consumption figures

 

Great Info!

I have done this procedure. I just cant get the darn idle to settle down to the 700-800 rpm

Not sure what I am missing.