Following an engine replacement, I've had an intermittent crank, no-start issue for some time on my 98 XJR. The no-start only occurs on a cold engine (after sitting overnight, or all day). Once started, it runs great.

After several threads in this forum, 3 trips to 3 different import garages (it's not losing fuel pressure), and myself replacing several parts (engine coolant temp sensor, battery, spark plugs, MAF + air temp sensors, air intake tubing, air intake gaskets), I think I finally may be getting close. The other day on a no-start condition, it tripped a code (the first time it has done that) the code being, P1336, or "camshaft position sensor circuit malfunction".

I've ordered both the left and right sensor, and I plan to replace them. My JTIS, however, does not describe how to do this. I know where it is, and I can handle the mechanical part, but is there anything else that needs to be done??? such as, a re-learn procedure, or perhaps just reset the PCU with a battery disconnect after replacing the sensors?? Has anyone else had to replace these sensors? Are re-learn procedures even necessary on these cars? My last thread about cam/crank sensor re-learn was not very popular (zero replies), so I hoping for more info this time. any tips would be greatly welcomed!!

 

There is only one cam position sensor, it is on B bank at the rear. Removing it may require removal of a fuel fitting that is in th eway.

 

That's interesting... I thought there was only one as well (I know where the one you are mentioning is); however, when an import garage was inquiring about ordering one, they were assured that there is two. When I ordered my own from RockAuto, they also had it listed as 2 (a left and a right). I assume you're right, so I'll just return the other one. I wonder why there is a mistake in the "system"?

Anyone know if re-learn procedure is necessary, after either an engine swap, or a cam sensor swap??

 

Plug and play, once you get the correct sensor.

LCA1646AD is for a supercharged (and N/A) AJ26, that is theone you are attempting to replace.

N/A AJ27 engines have two (to monitor both camshaftsonce the VVT system was upgraded to CVVT):

LRA1646DB, right side
LRA1646BC,left side

Your supercharged engine doesn't have VVT, or CVVT, and is not a '99 AJ27 anyway.
So you have two sensors coming, one you don't need and another that you can't use.


Backto the fault:

If someone has verified that your no-start is not a fuel pressure fault, that means they have tested the fuel pressure at a time when the fault was replicated. So if they found fuel pressureat no-start, did they check for injector operation at that time? Did they check for ignition system output at that time?

I'm going to stop now. Something my Mom taught me about not having nice things to say.

 

One thing I suggest you do before replacing is to clean the connector and check the harness for damage and continuity. Just recently I had slow start symptoms (long cranking before start), it was just bad contact inside the cam position sensor connector. Two good squirts with electronics cleaner and it runs like new again.
Jagtech is right, if you ordered two sensors for the AJ27, they will both be the wrong ones, the 98 V8 AJ26 only has one. I have rearly heard of a bad cam sensor on this model, look hard at the circuit like the code said.

 

By the way, all the harness checks that need to be done will be found in detail under the DTC number in Alldata.com. I suggest you get a subscription so you can get into these things with confidence. Its worth the $25 per year.

 

tried cleaning the cam pos. sensor connection w/ electrical cleaner - still no start. No obvious damage on the harness.

JTO....unless I've been mislead, the fuel pressure and injector operation were tested and cleared OK at the time of fault (morning no-start). I do not know if they checked for ignition system output at that time.

You're both right. They sent me the wrong damn part(s). The frustrating thing is that many of the online auto part suppliers have made the same error; they're all showing a left and a right sensor, and I'm pretty sure neither is the one that I need. If there was a jaguar dealer within 60 miles of my house, then I would just go there, but there isn't.

Any tips on where to find the correct sensor?

I'm about $100 away from taking a sledgehammer to this car.

 

I can ship you a new one for $152.00 total on Friday, of a good used one for $75.00 totalon Thursday. The latter would come from my "98 AJ26 N/A, which is a daily driver that is in perfect running order. I have others, testing them is up to me and not up to a prospective buyer.

 

that would be awesomethanks. I'll take the used one - please drop me an email for the details when you have some spare time (skanoski@usa.net),

 

PM on the way, and a couple of other suggestions with it.

 

A no-start when cold only would normally be related to the fueling system since it has sensors that regulate it according to engine coolantand air temp. The first thing would be the coolant temp sensor. If this is bad, and telling your ecuthe engine is warm when it is actually ice cold, you will get too-lean mixtures at the starts and no-go. These are cheap parts, you can test it or just replace it. Next is the intake air temp sensor. In addition, if you are still loooking at the cam sensor which could cause this, since if there is no cam signal, the fuelling will be inhibited,Alldata has a test procedure that is simpleusing just a VOM that will fully test the senor and its circuit. My only concern with this is that the cam sensor is more likely to fail when hot than when cold due to internal coil shorting upon wire expansion when hot. Testing beats guessing every time. If I had to guess, you have a bad coolant temp sensor or bad connection or harness to one of these sensors.

 

OM ... the first thing I did was a lazy test of the coolant temp sensor (got a live data stream from OBD2, and the coolant temp reading was the same temp as my garage). I then replaced the coolant temp sensor, b/c as you said, this is a cheap part. No-go on that. I then (probably following your same line of thinking), ordered a new air temp sensor, which in this car is a $300 part that includes the air flow sensor. No-go on that, so I returned the air sensors and put the old one back on. I believe on the 98 xjr there is a second air temp sensor, near the supercharger. I haven't replaced or checked this one, but I doubt that it's the problem.

I have no experience with multimeters, but I recently bought a decent one, and plan to test these circuits more thouroughly, assuming that my "new" cam sensor doesn't solve the problem.

 

speaking of cam sensors...... the parts company that I ordered it from (take your pick, they all have the wrong part listed) checked with "Standard Auto Parts" to try to resolve the mistake. Standard auto parts insists that they are correct, and that jaguar has never listed this part # (LCA1646AD) for an XJR, only for XJ8.
Obviously, Standard auto parts is wrong, thus making several of auto parts distributors wrong as well. I've had a similar experiences before with this car (EGR valve, cam cover gaskets, air intake tubing)

Bottom line, they are returning the cost of the part, but not the shipping charges because they insist that they are correct. I think I'm done ordering parts from these large online parts distributors. In my experience, their accuracy is barely over 50%.

 

Yes your 100% correct. I had the same problem ordering online 2, with my 2004 xj8

 

Wow -- responding to a nine year old post