Hello. New Here. So here is my dilemma. Was cleaning out the engine compartment and did everything needed per knowledge on the can. Used a simple garden hose with standard stream pressure. After completed went to start engine and it just Cranked but did not start. Used a blower to dry the engine bay out - still not start. 2 days later no start.

-Checked inertia switch seems good
- Fuel Pump is priming and pumping
- Fuel Pump Relay seems to be clicking (have replacement on order)
- tried other steps to resolve flooding that I have seen online.
- Car is last year made with No distribution cap.

Anything as in desperate. Car worked with 0 problems before and started Quickly between cleanings to reverse back 4’

 

Have you checked the spark plug wells? It's very easy for water to get under the cover and fill up the coil-on-plug wells.

Also AJ16 XJSs really don't like being started and then immediately turned off. That could be the problem if you just moved the car then shut it down.

Try churning it over with your foot flat down on the accelerator. Then as it starts to cough, lift up the accelerator a little bit until it fully catches

Good luck

Paul

 

Thanks Paul going to check the plugs. I really thought that the cover had a better seal on it but this morning before leaving I took cover quickly off and there was some water under that and and pooled in some screw holes for the head.

Tried the anti-flooding tips I have seen already on here acouple times with no luck. What do you think is “to long” trying to turn her over? At most I did 25 seconds with not even a caugh.

 

I;m with Paul.

Taht AJ16 cover is just Deco.

The "gaskets" under the coils are not much better. I never replaced them on the X300 cars.

The water in the plug holes is above #1 on my list.
Get a syringe to suck that water out of the plug wells, dont do what some down here have done, remove the plugs and let it run inside, FACT, some people should NOT be allowed near an internal combustion engine.

Dont kill that starter motor. 10 second bursts is OK, any more and that sucker will get HOT.

Unplug the Crank Angle sensor, just in front of the Cam Angle Sensor, and blow out that connector. WD40 replug it.

Then unplug the Cam Angle Sensor and blow that out also. WD40 again.

With the coils out, blow out the sockets and the plugs, WD40 again as you assemble them.

If that fuel pump is pumping, the relay is doing as designed.

 

Check to see fuel is getting to the injectors. I recently had a Fuel Pressure Regulator fail that was keeping fuel from the rail (V12). Pump, spark, filter were all working fine but without gas it wasn't going anywhere. New FPRs are expected this week.

 

So looking intro he spark plug wells and they are all dry. Extra blew them out with no change. Removed the CPS and it looks fine. Cleaned her up a bit with Dielectric grease into the fitting and still no start. Can replace it but not sure if it is actually bad. I usually buy parts on Jagbits.com but a lot of places have the piece cheaper. Also what is this piece that I have the picture of. It had a moisture in it.

Fuel pump relay replace- no change.
Pump primes
All fuses ok.
Replaced All engine bay Blue Hella Relays
- I am thinking this has to be in the engine bay due to the washing. Just not sure what else it could be.

 

Holy cow, you’re gonna go broke soon. Definitely shop around on jag part pricing.

I mix these parts up all the time.

What you have in the picture is the CAMshaft position sensor. If your RPMs are at 200 when trying to start the car, you’re probably fine. If not, I don’t care what it looks like, it’s dead.

What often fails is more likely to affect your starting issue is the CRANKshaft position sensor. You should, at the very least, pull that out and check it out, as the post before you recommended.

 

This is very timely for me also because I'm still chasing (not full time) a crank, no start issue right after I did the same engine wash. Ot's been over a year since I did th wash and it should be dry by now. It was running perfect before I did the wash. Go figure.
Vee, the AJ16 book says differently from what you said so I don't know whether to chase a Cam sensor or crank sensor. Starting input is done by the camshaft sensor and after start, running is done by the crank sensor. So if it starts but doesn't stay running, you could suspect the crank sensor apparently. But apparently you don't always need the camshaft sensor to work, as eventually, the ECM will use a vague attempt to eventually figure out cyl # 1 for firing using the crank sensor instead of the camshaft sensor if it were dead. I also googled some vids of a ford Taurus that had a crank , no start (I would suspect similar ECM/Ford) and it ended up being a bad temp sensor. They found this out using a VAG/COM of sorts that showed the temp sensor was way out of spec, maybe even shorted internally. Tris somehow prevented the engine from startling. Once the sensor was replaced and static values confirmed in the good range, it started right up.
Here's what the book says:

 

Hi C&P

A couple of other things you can Check

Passenger Side 'Knee Pad Fuse Box' one of those Fuses is for the ECM (can't remember the number) but worth checking them all, also try unplugging and re-plugging in the 2 X Blue Relays above those Fuses, especially if they are the type with thin Blades

The ECU is also down at the side of the Passenger Footwell where it is not uncommon for water to run down and get into the ECU and Corrode the Pins

The ECU is also so well hidden that you may have to send out a Search Party to find it, or you Can have a look at my Thread 'Carmen Won't Start' where I had to try every Trick in the Book to try and get her running, which I eventually did

Also don't overlook the obvious

Fuel Pump Cut out Switch by Passenger door Jamb in the plastic box might need re-setting

You could also be Low on Fuel, as 10 gallons hardly Wets the bottom of the Fuel Tank on those Cars

Also maybe water got into the Coil Packs

Coolant Temperature Sensor Not Working in which Case your Car won't Start but you can short out the Pins in the Plug with a Paper Clip or Piece of Wire to Test That as without the Coolant Temperature Sensor Working The ECU will 'Over Fuel' The 'Paper Clip Trick' will Fool the ECU into thinking that everything is OK

Could be the Crank Position Sensor

(1) Test it to see if it is Working should be 150 to 300 Ohms resistance

(2) Or it may have the wrong gap and the Gap needs adjusting Max Gap 0.042 (or less)

Good Luck

Alex

Carmen Won't Start! Almost every trick in the book to get my AJ16 Engine Started and eventually did

 

C&P,

Your analysis of the roles of the Crankshaft Position Sensor & the Engine Position Sensor are broadly true but there are a couple of subtleties.

The car uses the Engine Position Sensor to "help" start the engine. Once started the sensor does nothing to help the car run. As detailed it helps to minimise the number of turns before the ECM has worked out when it's one a No. 1 firing stroke. Technically it can work without it and would just need more cranking before the ECM has worked out the firing stroke.

But...the car absolutely needs the Crank sensor in order to run.

In simple terms, if you can't start the car at all, I'd look at the Crank Sensor first. If you can't start the car easily, maybe look at the Engine Position sensor

Good luck

Paul

 

Carsnplanes, well dagnabbit, I may have switch cam and crank again. Im sure someone else will correct me.

DBC10603 is the camshaft position sensor? That one is functioning if you see 200rpm on the tachometer when cranking the car.
LHE1640AA is the crankshaft position sensor and seems to be a common failure part that can cause a no-start issue.

The temp sensor is very easy to replace and very cheap to buy. If it hasnt been replaced, then I wouldnt talk anyone out of spending the $20 and spending the 5 minutes.

 

Matt,

I also have a 96 XJS and had the same issue.

There is a large connector passenger side engine compartment. It is mounted below the ABS valuing???.

The connector got wet doing an initial clean after I had purchased the vehicle. Even though I had it wrapped in Plastic and taped tight ....it got wet.

Very difficult to start. Finally got it running but it ran terribly. Took the connector apart (Bolted together) and cleaned and dried it out...Hair dryer for probably 15 minutes. Never had a problem since!!

Softball60/Paul

 

So still no luck.

- Replaced Fuel Pump Relay
- Replacement Crank Position Sensor (@front of engine)
—— now the Tac stays at 200 while key at starting position
- Blew out larger power coupler under abs added dielectric grease to connection
- replaced almost ever Blue Relay with new replacement models ( Jag says those go bad)
- Blew out Engine Inside Cam Postion sensor
—— maybe a get a rebuild for this
- check all other fuses
- did the gas flooded thing a bunch of times

what else in the engine compartment could getting wet cause for the car not to start.....

 

Hi Matt

If you've got a reading of 200 Ohms just by turning the Key and that reading Stays where it is, then it sounds as if you have no gap at all between the Crank Position Sensor and the Reluctor aka 'Cog Thingy Wheel'

The CPS on these Cars can be a bit of a Total PIA to Gap but you've just got to keep on trying, as any gap (within reasonable parameters) is better than no gap at all, even if you have to either make yourself some shims or give the Bracket a 'Tiny Little Tap' with a FBH

Matt it's a Jaaaaag and there will be Pain!

Have a look at my latest Post how to Test the 'Crank Position Sensor' How To Test The CPS Crank Position Sensor on an AJ16 Engine

 

MAttVo29,

Start with the basics, Have you got an absence of fuel and/or spark when churning the starter?

Pull one of the plugs maybe no.6 Carefully, using insulated pliers or similar, earth it to somewhere safe whilst turning the starter. IS the plug sparking? Is fuel being injected to the cylinder?

Paul

 

So

Gas : Yes (now with New Fuel Relay)
Spark : Yes

Had the old Fuel Pump Relay in and it was making something do a soft Tap. Once I replaced it with the unit that went away. Got a nice sound from the fuel pump and when cranking got a good stream of fuel. Strange for the old to be bad not sure what could’ve caused that while washing our the engine.

..... anything else. It has to relate back to the engine compartment clean out.

Thinking about going the Jeremy Clarkston route with a nice mallet see where that gets me.

 

Possible be the ECU? From what I have seen it is located inside the vehicle.

the car only have 48K miles

 

Hi Matt

Yes! it's way down at the Side of the Passenger Footwell where there is also a well known issue of Water being able to trickle down behind the Trim and maybe corroding the Pins of the Plug where it plugs into its Socket

But it's such a Total PIA to get to, assuming you manage to find it as its so well tucked away, that I wouldn't bother going there for the moment, as from what you have said so far it seems much more likely that your Crank Position Sensor needs to be Set up properly with the right gap being 0.042 or a fraction less

On the end of the CPS is a little metal probe that picks up the Signal and this is also a very powerful Magnet that is entirely capable of holding the weight of something like a Spanner which of course can make the act of trying to get the perfect Gap that much harder, as being a Magnet it will be attracted to anything made of Metal

So you do need to be very Careful that this Probe doesn't get damaged by any physical Contact with any moving parts and just to Cheer you up even more, if anything should go wrong with the CPS while you are driving, then it will Stop the Engine Dead just like you Switched it off and I know this because it happened to me

Water and XJS Engines simply do not mix and even damp HT Leads are more than enough to prevent an Engine from Starting if they are touching each other

 

Ok. Going to stay clear of the ECU for now.

For the CPS the new on is exactly the same length as the old unit. So not sure on the whole gap thing. Also it is pretty stationary in its mounting bracket not sure how change it.

The new unit is stronger and can pick up a ratchet tool but the old one is pretty close to the same strength.


- Gonna try the spark test again. If no spark and the CPS is good. What should I check next.

 

Hi Matt

Setting the Gap on the CPS can be fairly Crucial if you want to get it to work in the way that it should but with any Gap wider than 0.042 it very likely will not work at all and as for the Strength of the Magnet itself, that really doesn't come into play at this time

As far as setting the Gap is concerned some of the CPS's have Shims while some of the other types don't and we are talking tolerances of Thousands of an inch and so sometimes you have to get 'Creative'

On my V12 XJS when I changed the CPS and went to do the 'Gap' I had to file the holes in its mounting just a little bit longer and even ended up Tapping the Bracket with a Hammer to get it to work

Though as of now you've have got yourself a New CPS what I would do at this moment in time, is to Gap it as best as you can and then have a check to make sure you didn't get any water down those Coil Tubes

Then do exactly as Paul (ptjs) suggested and make sure that you have got a BIG BLUE SPARK and that the Fuel Rail is also getting fuel