The fittings Jaguar used are fairly intuitive and not like the satan's a$$hole produced stuff Volkswagen uses with weird retainers involved and push out versus in, etc. The throttle body and maf connectors are the push the little rocker thing and pull back. Like this where you push on the bit in the middle and pull the plug back.


The clamps are of the spring and screw kind and very straightforward. This is assuming you are NOT pulling the elbow beneath the TB with the EGR bolted on to it. That has hard lines from the crank vent system that are a bit harder and different.

 

The keyword here is patience. These plastic connectors have gone through many hundreds of heat cycles in the engine compartment and tend to get brittle with age, and pushing on the tab often takes more force and wiggling than you might think. Avoid using a screw driver to separate the connector from its socket (ask me how I know) and you should be fine. It often helps when assembling to put a tiny dab of die-electric grease on the metal contacts; makes disconnecting them the next time a little easier.

 

Excellent connector photo. If that doesn't terrify zray then nothing will.

Not really necessary to remove the TB to clean it. The MAF is a delicate item.

Graham

 

thanks the response and the illustrative photo !


thanks for the screwdriver avoidance tip, I was sure to use one

re the use of dielectric grease.
FYI, ....or to whom it may concern...

Despite the widespread use and endorsements, dielectric grease should never be used on the metal parts of an electrical contact surface, like the blades of the headlight switch for example. Used sparingly on these metal contacts, dielectric grease won't cause much harm, but it certainly is doing no good either, as the current is being passed in spite of the dielectric coating, not because of it.

there are many commercially available product that will improve electrical conductivity, in liquid, paste or grease formulations. The silver based ones are usually pricey. All of them do a great job, especially when compared to the widespread, but misguided, use of dielectric grease.

https://www.britannica.com/science/dielectric

QUOTE: ".......Dielectric, insulating material or a very poor conductor of electric current. When dielectrics are placed in an electric field, practically no current flows in them because, unlike metals, they have no loosely bound, or free, electrons that may drift through the material. Instead, electric polarization occurs. The positive charges within the dielectric are displaced minutely in the direction of the electric field, and the negative charges are displaced minutely in the direction opposite to the electric field. This slight separation of charge, or polarization, reduces the electric field within the dielectric......"

As the definition of dielectric says, it is an INHIBITOR of electrical current, not an enhancement, as many people mistakenly have thought. It is great when used on the rubber or silicone spark plug boots, or the rubber boots around taillight bulbs, etc. Used in such a manner it helps to insulate against a current leak or moisture intrusion.



this is a good CONDUCTING grease to use for automotive uses:


and this is even better, but pricey:

#1


Any more comments re the throttle body removal would be highly valued !!!

Z

 

If you do remove the TB pay close attention to the alignment of the bore when you remount it. There is some slop in the mounting. Mine was off slightly when I got my car.

I always dump a bottle of the Chevron Techron cleaner in the tank right after I clean the TB.

 

Can you expand on the idea of cleaning the throttle body without removing it ?

re the Techron cleaner, I use one the big bottles of it on every other tank of gas, hoping to mitigate lack of maintenance by former owners. Any danger of using it this often ?

Z.

 

yes, the photo is scary. Am looking for my HAZ-MAT suit before entering garage.

what come off to clean the TB without removing it ? Sequence ?

Z

 

I didn't break any connectors when I replaced my TB. As noted above, they are relatively easy to work with.

I've never in my life felt the need to clean an EFI TB that involved removing it.

 

Just a few suggestions.

Do one thing at a time. Then if something messes up you know which item it is.

Take a photo of the object your dismantling. Its obvious which way around it goes or what screws go where when its on. After its removed its not so obvious. Either keep the screws in the holes you removed them from, use masking tape to hold them in. Or use a plastic bag. Can be very annoying being one screw short.

I agree with above too. Clean while in place if you can. Dont forget the throttle body also has a fine coating of some material, dont ask me what it is.

 

The goal of cleaning the TB is to remove residue that can impede the movement of the butterfly.
If the butterfly can't pivot smoothly then the TPS doesn't work correctly either, causing those pesky codes, etc..

Here is a good video that is sort of a "you and your XK8 throttle body" to get familiar with how it is put together.

On both the 4.0 and 4.2 engines it is safe to open the butterfly manually. But be gentle. The throttle position sensor is connected to same rod that pivots the butterfly.
This gives you access to the entire bore so you can clean it with your choice of cleaner - without having to remove the assembly from the engine.

I use the CRC brand cleaner and an old toothbrush.
I then mop up as much as I can of what falls down into the intake manifold using old tube socks wrapped over a plastic dowel.
I use the Techron tank additive to give the entire system a good cleaning. I don't think it hurts to do it every other tank but a couple times a year has worked for me.
Takes less than 30 minutes to clean your TB this way and way less risk of breaking something else in the process.
I have done it this way at least ten times with no issues after.


If your **** retention factor is high like mine you might notice a misalignment of the TB causing a lip like you can see in the above photo of mine.
I was daring enough to loosen and adjust the position of my TB to better align it and get rid of that lip.

 

Jet-Lube SS-30 Anti-Seize Thread Lubricant and Conductive Termination Compound

www.amazon.com/gp/product/B001HWBTPK

this is also great product for two uses, anti-seize and electrical. it is especially good for battery connections after they are cleaned. we have used it on boats for years on all terminal connections as it waterproofs as well as enhancing conduction. be neat with it as it is known as the mess in a can.

 

Lol! To me that looks so easy compared to a VW one with the little inserts that you pull out and then hope you don't crack the connector taking it off. I broke at least 5 connectors on my A8 in the 5 years I owned it, definitely didn't have those issues on the Jaguars, GMs, Fords and other stuff.

 

 

Glad it worked out well. Did you give the MAF a spray of its cleaner too? I usually do that whenever I have the the intake tube off. Forgot to mention it before.

You can get those rubber studded mounts cheap here. I bought two for future use.

 

thanks for the pointer to the rubber studs.

yes, I took out the MAF and gave it a good spraying with the CRC brand of MAF cleaner, taking care not touch the wire with the spray nozzle tube. Read somewhere on this forum to be careful to avoid such contact. Also sprayed down electrical plug contacts with CRC electronic cleaner and dried them with hot air.

Z

 

ZRay,

You don't need to remove the Throttle Body to clean it, just spray it good with Cleaner.....Be sure to look over the Breather Air Duct that runs from the MAF Sensor to the Throttle Body as they tend to get holes underneath them with all the vibration and such.....Any holes or cracks will mess up what the MAF Sensor is telling the ECU and you will get a lean running signal......also, don't clean the MAF....Replace it! They don't cost that much and make sure you have a K&N Filter.....Last but not least, make darn sure you tighten the Breather good to the Throttle Body..! This would also be a good time to replace your MAP Sensor, since you will be right there by it.....They get tired after a while!

Billy Clyde in Houston.…..