Hi,

My 1999 XJ8 is computer is flagging DTC's P1384 and P1396.

I looked up the troublshooting steps in JTIS and on the test of the "circuit for short to high voltage" on the Variable Valve Timing(VVT) connectors, I am getting 9 volts on the + (OY & OG color) pins on the connectors (both right and left side). On the - sides (RW & RG color), I get about 1 volt.

The troubleshooting step says that you have a problem if the voltage is more than 3 volts, which it is on both of my + VVT connectors. Its helpful suggestion is "repair the short circuit to high voltage".

I am really not sure how to find this short circuit. It seems to me that it is a problem with the ECM.

Any troubleshooting suggestions?

 

Easy stuff first-Make sure all connections are clean/good-- Disconnect and reconnect the modules in the passenger side hood/bonnet compartment. Also disconnect and reconnect the Cam position sensor ( rear of engine valve cover on driver side Do you have 12 volts at each of the VVT solenoids? If not What iiis voltage! Did you check Resistance across the VVT solenoids---I think they should be 10 to 12 Ohms. Can you Hear the VVT solenoids Operating? You should hear a Click/Clack sound about every 3-5 minutes.
Your Vehicle should still perform OK == Just not at Peak Performance
Give me more info --and I may be able to help

Good luck

 

i took off the VVT with out using the alignment tools. I didnt know you need to used them upon removal. I reinstalled the VVT with the tools and know my cam timing is advanced.Everyone can tell me how to install the chains...and how to use a computer to see how advance and to jump a tooth and so on. I just want to know how do i align the VVT to were it should have been if it were removed it with the alignment tool? How do i fix this problem? they say buy a new VVT from the dealer that will be preset a zero but wouldnt the gear still need to be in a certain position?

 

Its a 2001 4.0 s type

 

There is a link to a very complete pictorial of both the primary and secondary tensioner replacement including the VVT's in the XK8/R FAQ sticky under 'engine'

Or here it is: http://www.mediafire.com/?mijhydngtog#1

The off-forum storage of this .pdf file contains several layers of difficult-to-escape advertising. Get through that, down load the file and you will not have to put up with it again. We really should host this file on the forum's servers.

 

Although I am not understanduing exactly what transpired, there is no worry about not using the tools to disassemble the chains, Just set the chains according to the procedure with care to "unwind" he vvt back to home (see step DD and EE in the writeup) and you will be good to go. Look to ebay for the tools.

 

Ok...i've taken apart this car 4 times. I have correctly install the timing on every case.all times i have adjusting the vvt in most retarded position. One of the times i advanced it tell it bottomed out. That of course didn't work. Each time a get a a check engine light of timing cam advanced. Little rough idle. I have replaced the vvt and the sensor during this proccess. That car had no check engine lights at all and was running perfect before it came in. The only reason it came in was for a valve seat was loose in the head.
Now...from what i understand is when you use the alignment tool to remove the vvt it holds the vvt in its zero position. Then i heard when you remove the vvt with out the tools the vtt moves internally? What? I know.... Their is marking in side of the vvt now that i look at it. They are not lined they are at a 90 degees. If this is true how do i line it up? Of its not true why am i getting a check engine light if i am doing everthing by the book?

 

A little more.... When i tear down the car, the cams are in the correct position so i know the timing at the cam rods are correct because the cams are flat on top dead center and the timing at the crank is correct. So the only thing is left is the vvt. The vvt work it does bottom out both ways retarded and advanced.

 

What is the write up? Were do i see that?

 

Unfortunately, you do not have enough posts/time on the site to see the attachment. It is not your fault. If JIMC64 sees this post, he can help you get a copy of the file by advancing your membership to full status.

From reading this, if you're statically timed correctly and you can rotate the cams clockwise two turns and reproduce the correct static timing, then you have a bad VVT, VVT solenoid, or ECM issue.

As long as the timing is repeating itself statically, then the only other ingredient here is a failure in the VVT train dynamically, like a weakened or broken spring in the VVT, a defective solenoid or a clogged oil passage way, or a faulty ECM signal (which can include harness pathways).

 

QUOTE
"A little more.... When i tear down the car, the cams are in the correct position so i know the timing at the cam rods are correct because the cams are flat on top dead center and the timing at the crank is correct. So the only thing is left is the vvt. The vvt work it does bottom out both ways retarded and advanced. " UNQUOTE

First be aware that Jaguar does NOT time the engine at TDC. It is 45 degrees AFTER TDC so no piston is at TDC and cannot contact a valve.

A 4.0 S-Type has a very similer engine to the XJ8 but the AJ28 has 5 reluctor vanes on the intake cam vs 4 for the AJ27 and 1 for the AJ26(for the CMPS). That being said it should still have the same VVT as the AJ27 so it is continuously variable. You should also check the 2 sealing rings for each VVT oil supply orifice (NNE2622BA). The part number may be superceded so check for that.


bob gauff

 

Their is no timing marks on my flywheel so i cant be 100% sure it will line it up for timing? Is their any other types of markings?

 

Thank you for the info...its help me understand alot more....then only thing is their is no timing marks on my flywheel when alldata, mitchell. Ect. Say their should be a triangle mark? Is their anything else that i should look for instead of the triangle?

 

The timing slot is different from the square slots as it has rounded sides. Remove the crank position sensor and the odd sized slot is the one that lines up. There is an elongated one for reference and that is not the one you are looking for.

bob gauff

 

I did find this different slot. When i lined it up, i noticed the piston was almost half down the block? Is their a diagram for this different markings?

 

Can you explain the unwind?

 

Yes, I've explained this several times myself, that the static timing mechanism utilized in the AJV8 has nothing to do with TDC. Part of the technical reason is that the valve train design is asymetrical. In several places along a single camshaft assembly rotation, there is uneven or unbalanced spring pressures acting on the cam shafts. The designers chose a position in the crankshaft rotation where this imbalance is null. That way, all four cam shafts can rest without spring pressure acting in one direction or the orther to roate them.

 

ok....i rebuilt this engine...so i know i took off the flywheel....could i have put on the fly wheel in a different position? or is their only one possible position to install? i think i might need to pull the tranny if that was the case?

 

if you have a triangle timing mark the square holes on the flywheel the triangle is in between the the two squares. the marking i have is a rounded square. the question in wht position whould i have to line that to? the rounded square now falls straight on. different from the triangle..

 

I got the answer!!! Yay....everything is lined up...and im putting it back together,,, the vvt is to zero by lining up the holes in the vvt... The flywheel has no triangle but has a special tool ans is now lined up....once the flywheel was lined up the cams were off...and had to be realined....now everything works.....thanks alot to all the peeps that gave me info....now i can do it with my eye closed and one arm tied to my back.....lol....