How To Clean Maf Sensor Jaguar Xjs 1995 Aj16

Crankshaft Bolt removal:

The crankshaft bolt requires a substantial 1 ⁵/_xvi " AF or 33mm socket, a substantial ¾" breaker bar and length of potent pipe to fit over the breaker bar.

Firstly, remove the under tray and radiator fans.

I then removed the crankshaft commodities using a pipage over the breaker bar, placed against the floor. The pipe allows infinite adjustment to ensure all is tight and yous accept a adept angle on the bolt. Remove the fuel pump fuse (trunk fuse box) so the engine won't try to get-go and then one "bump" of the starter and the bolt came free.

To get the damper off I used two levers confronting the sump casting - naughty merely its held in place by a woodruff key and so slides off (adequately) easily. If you must use a puller, locate the legs on the timing bicycle, not the pulley, as you lot could damage the damper.

To re-torque the bolt y'all must prevent the crank from turning. The Jaguar tool is a bar that bolts to the balancer and braces confronting the chassis to continue things rigid. However information technology is unlikely to come undone if yous utilize a heavy hammer and/or impact tool and Loctite.

If yous have been working on the timing chains then now might exist the fourth dimension to plough the engine over manually to make sure the valves aren't getting besides friendly with the pistons.

Temperature sensor: the ane that controls the ECU - Not the dash estimate

A new temperature sensor: function no: LHE1600AA

Iced water = 5360 ohms
Room temperature = 2800 ohms
Humid pan of Water = 195 ohms

Mine: engine cold (10°C) - about 3,000 ohms; engine hot - about 500 ohms so well-nigh correct.

Spark Plugs and Coils: misfires

<----- This is the label off a genuine Lucas original coil

I use NGK BCPR6ES gapped at 0.030" (spec is 0.036" but the narrower gap is easier on the elderly coils!).

BCPR6EIX is the Iridium equivalent - see hither for explanation of NGK nomenclature.

<----- This is a coil existence cut open - the whole within, including the active components and the coils, is rigidly potted and so not serviceable.

The FM Radio ticking noise turned out to be a badly corroded curl pack tip. I would recommend pulling the kick off all coil packs to check for corrosion when changing spark plugs. All but one was pristine. The corrosion was and so thick on one you lot could not run into the shape of the tip.

<----- Lightweight springs brand the connection between the coil pack and plug - stretch them a little so they positively fitted on the end of the plug.

Use electronic cleaner at the ringlet end and brush them clean with a small brass bristled brush.

<----- and some other view of the sawn-up coil

While y'all're at it brand sure the gaskets that fit between ringlet and cam embrace are secure and that all electric connections to coils are make clean and secure . . . . . they live in a pretty hostile environment heat wise.

Individual coil checking: from Neil Maldon

If yous have an oscilloscope with a CURRENT probe, have the plug cover off and check the current pulse on each coil pack.

It should be solid i.e. a sharp rate of rise on the leading edge and exponential decay for a menstruation and a sharp cut off at the stop. Any fluttering and/or rise and fall within the pulse indicates a failing ane.

or see here if you lot want to go into real item!

Loftier Idle: from Mike Jones

Can be acquired by a faulty Throttle Position sensor - quite perchance intermittent

OR tin can be caused by a faulty ISCV (Idle Speed Command Valve) - externally visible on outside of throttle torso:

Idle speed OK (around 700 rpm) when running up to normal operating temperature (closed loop) merely when taken for a run, idle speed increased to effectually 1600 rpm.

Checked throttle butterfly returning and not snagging or sticking. Checked inlet pipework mail MAF for vacuum leaks merely unable to mistake.

Plugged in OBD2 via laptop (using Proscan). Noted that as presently as engine running in closed loop command MAF reading gradually increased from 0.05 to 0.07 (sorry can't recollect the units). This indicated to me that ISCV non stepping correctly.

Removed throttle body, so remove ISCV and the Throttle pot (very carefully!!). Throttle torso surprisingly clean but gave it a good clean with cleaning spray. Sprayed Throttle Trunk pot with contact cleaner. Cleaned ISCV and then checked the two coils. Both checked out OK at around l ohms.

Plugged ISCV in and keyed ignition on then off. Noted that ISCV piston motored in then out as it should do. Decided to re-assemble everything and refit.

Fired upward the engine but fault still nowadays and same symptoms.

I had a spare ISCV (ebay 99p) that I purchased almost v years ago. Over again removed TB then fitted replacement ISCV.

Re-assemble and fired up. Took automobile on a good run and all OK. Idle speed steady at 700 rpm (park). Accept been using for several days at present and no farther problems.

Seems that original ISCV was faulty but not certain why.

Crank Sensor:

A new X300 crank sensor has a resistance of around 1,300 ohms and inductance of about one Henry. The Jaguar function number is LHE1640AA. If the sensor is working, the tachometer should jump upward to about 200rpm or so when cranking but not firing.

On the bench, with the sensor connected to a peak-concord DVM, flicking a steel-bladed screwdriver back-and-forth beyond the magnetized 'pip' in the centre of the sensor'south face yielded peak voltages of around 250mV to 300mV depending on the speed at which the screwdriver moved.

These sensors exercise neglect completely merely can besides partially fail and give disruptive and inconsistent problems from no-starting time to intermittent firing.

My ain feeling (without conclusive proof) is that they deteriorate over time. The Crank Position Sensor is a sensitive electronic device stuck out in front of the engine and subject to all sorts of air current, conditions and engine estrus cycles. Basically information technology is a coil and magnet - peradventure the magnet gets weaker, peradventure the coils start losing insulation - who knows?

I did find, when chasing a fault on my 1995 3.2 Sport, that putting a new CPS reduced the trouble I had and in fact I connected to use the car for some other two weeks earlier having to diagnose the real mistake.

And then my guess is that the waveform off the new CPS was much ameliorate than the original such that it was able to partially mask the existent fault.

Engine Timing the easy mode:

refers to the problems I have had in ascertaining the correct manner of setting upward the cam position sensor (the unit where you might expect to observe a distributor) when it took several churns of the engine before it would burn (though information technology was fine one time running).

pull the crank around (use a 1 ⁵/₁₆ " or 33mm half inch socket on the crank bolt - information technology Merely fits without removing the fans) until the missing molar is exactly under the CRANKSHAFT SENSOR (not the POINTER).
await at #four inlet cam lobe through the oil filler cap hole - if it is up then this is the correct TDC. If the cam is downwardly (i.e. pushing the valve open) then rotate the engine 360° and bank check over again.
remove if necessary and reset the CAM POSITION SENSOR and then the dimple shows in the window. Information technology is easier to see where you are if you have the tiptop off (20 torx). You should terminate upwardly with the dimple alongside the scroll thingy on the right hand side. When the top is replaced the dimple should be in the centre of the window.

Now the engine starts IMMEDIATELY on the first compression and without jiggling the accelerator pedal.

I initially set the missing tooth against the pointer - big mistake and information technology wouldn't burn down at all. Which leaves the question - why is the pointer there in the first place every bit I cannot encounter annihilation to line it up to.

Although I used a ¾" socket to become the crank commodities off when I did the timing chain guides, this large spanner won't fit when the fans are in identify so I bought a shallow ½" socket (1 ^five/₁₆ ") as I was only pulling the engine over.

In my defence, I put everything back "every bit information technology was" - the engine was not proficient at starting before but as it is my first Jag I didn't know what to expect. It now appears that I bought it with the cam sensor gear up about 120° wrong! No wonder nothing made sense though information technology proves how good the electronics are!

Oil Pressure Sender:

The sender (function number LNA 5642) is a switch located on the side of the engine block, underneath the inlet manifold and side by side to the oil filter, and can exist identified by the single wire lucar connector and a large bore fixing nut. Removal is elementary from underneath after pulling the wire and using a big socket.

Early on X300'southward had a true force per unit area sensor (DBC 5513), which is apparently prone to erratic readings every bit a result of the carbon rail of the potentiometer wearing out. Because of this, and customer concern over reduced oil pressure at idle, which is perfectly normal, later (1995 onwards) X300'south and dealer repaired early on models had the simple pressure switch fitted instead. This is linked with software reprogramming the instrument pack to cause the needle to sit either at the mid-point, or at zero dependent on the switch.

Today (2010) it is still possible to retrofit a complete late (1990-1994) XJ40 instrument pack. If this has non been reprogrammed and so it fits exactly (basically the same unit) and yous become proper oil and temperature estimate readings. You lot will need to fit the earlier pressure sender (DBC 5513). Tighten with a 19mm crowsfoot spanner or an 18mm if a design version - you will see why when y'all try to practise the job!

Having proved this works, and the meters worked well, I was eventually forced to give up as information technology raised a number of problems with some of the alarm lamps and the computer switching - Come across this page

Oil leaks virtually filter (XJR):

An oil leak which looks to be coming from below the oil filter housing might be from the featherbed pipe which is the little half do-nut thingy below the filter housing.

A unmarried, central nut allows the pipe to be removed (kind of a U curve pipe) and y'all will see clearly an O ring on each stop. These dethrone over the years probably with estrus etc and it's a uncomplicated example of replacing them. don't use EPDM rubber rings, only nitrile, preferably viton. I think this is the number KSH119530. Yous don't need to drain the sump although in that location will be a lilliputian oil spillage.

The other path is to remove the "sandwich" of the adapter. One new gasket and 4 shorter bolts and yous tin can eliminate the o-rings permanently.

Camshaft embrace: refitting

You will need the cam cover gasket, two semi-circular seals, the six spark plug well seals and 13 seals for the bolts that agree the cover onto the cylinder head.

Sit the new spark plug seals on the cylinder head instead of trying to fit them into the cam cover.

Insert the gasket at the windscreen finish and work your way forward to the radiator.

Both the gasket and the spark plug well seals don't want to stay in position simply the above should work. Clean the inside of your cam cover particularly the mesh oil breather filter.

No starter motor action:

Get-go - jerk the gearstick in Park and you should hear the relays click in and out; if non then possibly the microswitch in the centre console is faulty. This is a fairly common fault.

A new microswitch would certainly be preferable to any of the options below!

There are a couple of relays you demand to cheque to make sure ability is getting to the starter solenoid. (from Jeff Watson)

Under the bonnet/hood are two fuse boxes with a relay in each box. Towards the front on each fender. The relay in the LHS box is for the horn, the relay in the RHS box is an IGN relay which should ''click'' when you turn the IGN key to ON.

If it doesn't ''click'' swap information technology with the horn relay and try once more. If it does ''click'' the first time the next relay to await at is in the cluster behind the LHS headlight. There should be one with a large white wire with a red trace coming away from it.

Information technology should ''click'' when you plough the IGN key to Showtime. If it doesn't click you can temporarily insert the horn relay into the socket and endeavor it again. If the relay behind the headlight does ''click'' and you get no cranking so the next culprit is the starter solenoid.

Sometimes they stick and won't pull in and sometimes you can free information technology up past holding the key to START and firmly tapping the torso of the starter motor with a large wrench or slice of pipe. The starter motor is on the RHS of the engine towards the transmission bell housing. There will be a heavy duty cable going to information technology from a last on the firewall.

If it is a relay that is the problem then it is easy to replace it. If information technology is the starter solenoid then yous will have to remove the starter and get it rebuilt. :-(

Starter Motor removal: :-(

from Mechaniac - not too much of a pain, once you figure out that one of the ii bolts holding it on is removed from the rear of the bell housing flange (and someone hasn't, in fact, sheared the caput off the bolt) - a couple of extensions and a universal joint should accomplish it.

A pocket-sized mirror would exist helpful to let yous see what sort of fasteners are holding the wires in identify - quite hard to meet in the relative gloom from underneath the car. It's impossible to run across anything from to a higher place the engine!

One other affair I would mention is that on mine, at that place was a thick black atomic number 82 running from the alternator to the big terminal on the starter motor. In the dark confines of nether the engine, information technology was hard to see it pop off and away when I undid the nut on the terminal. Not realising this had happened, when I re-started the motorcar, the bombardment calorie-free would not extinguish!! Took me a bit of head scratching to sort information technology out and figure I had asunder this lead and non re-attach it!

and from Andrew Bernstein, British Auto Care

Nether machine, tear off the top left corner of the foam insulation pad.

⅜" bulldoze half dozen indicate deep well 13mm socket, with:
⅜" drive wobbly tip extension, half-dozen" length, with:
⅜" drive to ⅜" drive universal joint with:
⅜" drive extension, iii ft. length with:
⅜" drive to ½" drive adapter, with:
½" drive breaker bar or long handled ratchet.

Annotation - in my opinion, it would be better to use ½" drives (if you can become them in!) not ⅜" - and a 13mm IMPACT socket - and an affect wrench.

Y'all don't have to remove anything just the bolt . . . and the starter. They never damage the ring gear on XJ40/X300, the drive just explodes.

OR - access via the obvious route from the meridian after removing the wiper motor assembly (but exist aware this won't work if the bolt is really tight).

No start or erratic throttle response:

Assuming fuel force per unit area is OK (effectually 40psi) and the Creepo Position Sensor is OK then the next thing that tin be faulty (especially over 120,000 miles) is the throttle position sensor (TPS). This is inaccessible equally it is fitted under the throttle torso.

Yous will need to remove the throttle body - not a two-minute job. The numbers on mine (1995 3.2litre Sport) are 4TB 42739A and NBC3061CA and 4896

One time the throttle body is on the bench, remove the stepper motor and the TPS. Exist very careful every bit the securing bolts are quite long and are locktited in - remove a little chip at a time and get some Pb Blaster or equivalent onto the threads every bit they become exposed.

The TPS is Jaguar number JLM12074 - it is marked Ford and 70418A and 6J05A and has three wires coming out of the connector:

Black - blueish = 3,390 ohms;
Black - light-green = 495 - 3,450 ohms (moving smoothly every bit the throttle is rotated)
Blue - green = 67 - three,050 ohms (moving smoothly as the throttle is rotated)

Besides - a useful diagnosis guide from Mick Gannon in answer to "fast idle":

Take y'all gone back to basic's and cleaned all of the throttle torso parts to ensure that the throttle spindle/butterfly valve assembly in the body rotate and shut without sticking and removed all grime and oil glue residue from the throttle diameter, cleaned all of the electrical contacts, reassembled correctly and made a gasket or used the Hylomar 102 black auto sealant to seal throttle housing to manifold (not stated in process but listed in canonical sealants) - all of this must exist washed beginning along with checking any air leeks into the manifold organization.

The system is mechanically unproblematic: a leak downstream of the Air Flow sensor = high idle

The electronics are besides unproblematic: you take a supply indicate and a return betoken to and from the throttle pot (TPS), temperature sensor, Idle Speed Command Valve (ISCV) and Air Flow sensor

A pause in signal to the TPS and the engine will not beginning

Temperature sensor signal break or incorrect resistance will give over fuelling

Air flow sensor error will give no start or weird running

ISCV valve sticking seized or no point will give a high idle

Notes on O2 (Lambda) Sensors:

For a 1995 Jaguar X300 iii.2 Sport - taken from the In Service Frazzle Emission Standards for Route Vehicles

Tickover (@ 650 - 750 rpm): Max CO limit = 0.5% (mine = 0.00% May 2022)

Fast idle examination limits (@ two,400 - ii,600rpm)
Max CO % vol = 0.3% (mine = 0.02% May 2022)
Max HC ppm vol = 200ppm (mine = 8ppm May 2022)
Lambda = 0.970-1.030 (mine = 1.004 May 2022)
Min oil temperature = 80°C

I believe X300 Jaguars use the more reliable Titania blazon lambda sensors and not the more usual Zirconia type.

come across here for an explanation of how the Titania type of sensor works.

see here or come across hither for explanations of how the Zircania blazon of sensor works.

and see hither for the list by one supplier - no connection with any of the firms of course.

Difficult plugging and unplugging the lambda sensors? do this modification.

Eddie Birch did the modification this way: I believe I used a 17mm open ended spanner (please double check just before y'all start the functioning) with an approximately 20 degree curve in the 'bar'. The bend allows easier access to the sensors if y'all are going at them from the underside of the vehicle.

I found mine very easy to release and copper greased the threads of their replacements. I needed, but didn't have, a 12" bladed flat headed screwdriver or equivalent to reach between the engine and the gearbox to prise out the sensor cables from the two clips. The trouble is it is very dark in there, so you can't see very well, and the clips hold both the sensor cables and i additional cable in their jaws and these are really awkward to leave.

You will also need three good sized plastic ties to secure the new cables to the new route you choose for them. To embroider the instructions given on the lpg website, and although I yet painted both ends of one sensor connexion for safety, I did not disconnect the sensor cables from the loom until I was set up to conduct out the actual switch over. This minimises the adventure of crossing over the sensor cables and sensors. At that place is enough of spare cable to practise this afterwards yous have freed the onetime cables from the loom.

In that location is too a torx secured closed, round clip attached to the lower function of the car. Both sensor cables also pass through this but to remove it from the car to open it to allow the cables to be withdrawn would, I felt, be extremely fiddly.

When everything had been readied for the quondam sensor removal I therefore cut the cable(s) to enable it to be pulled through this clip. When I routed the new sensor cables I cable tied them to the outside of the clip to go on them away from the exhaust. I plant that freeing upwards the old cables from the loom and from the clips was the only awkward function of the job.

When renewed and re-routed any future sensor changes should be much easier.

Source: http://jimbutterworth.co.uk/8engine.htm

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