I bought 1989 Jaguar XJS with 5.3 HE engine.
I tried to get it running before storage, got to finish up another project and save some money for it.
It has been sitting for 12 years, it has spark but getting no fuel, rigged up external fuel pump in fuel canister. So far i have read tons of topics about no injector pulse and i havent found the issue so far.
Rotating throttle to full gives no click in injectors. Injectors are supplied with 12V.
It has Marelli ECU and i confirmed that there is continuity between ECU pin 24 and EFI ECU pin 18 (white shielded wire) also it’s not shorted with wire shielding.
Tach doesn’t move when cranking the engine so im wondering if it can be faulty CPS, but would i be having spark with faulty CPS?
I have tried looping CTS also confirmed resistance on the sensor and it seems fine.
So far i haven’t check if TPS needs adjustment but im assuming the injectors should be firing even with uncalibrated TPS. Also i think that main relay is dead, it doesn’t click when shorting the pins, i grabbed random relay from the shelf and replaced it, not sure if it needs to be somewhat specific relay or a random one that plugs in can be used.
Ive read that there are 2 sensors detecting engine rotation, one is near the crank pulley (CPS) and another one on thje flywheel. Which one of these does what exactly? Shouldn’t i still get tach reading with one of these working?
Alvar, One of our long time members, along with assistance from other members, recently developed a checklist to assist members and new vehicle owners with a non starter V12 engine. You can be the first guinea pig (that I know of) to see if it helps you diagnose your engine non-start without members posting multiple replies and areas to check. I could post several items you need to check, but…I suspect you will find your answer once you work thru the checklist.
In the upper right of this page, use the magnifying glass (search icon) and type in “V12 non running check list” by Richard Dowling. Let us know how it works for you and welcome to JL.
SD Faircloth www.jaguarfuelinjectorservice.com
I built external fuel rig for temporary testing with capable walbro pump, i have flushed the system and also have return line returning clean fuel back to my external system. Fuel rail is pressurized, injectors might be stuck but i wouldnt still hope hear them click. Trying to get hands on oscilloscope to see if im getting injector pulse and also if CPS is working. If those things check out i guess the EFI ECU is dead. i have pretty much covered everything else.
The much cheaper method for testing injector pulse is buy a Bosch style Noid light. It will test if you are getting a signal to the injector connector on the injection harness. Mactools makes one.
Part # ET3055D-8 $9.00 US. Where in the world r u located ? SD Faircloth
NOID light shows injector pulse when turning on the egnition for a moment and again when i flip throttle fast, no pulse during cranking. And now i realized i havent got spark anymore. I have pretty much checked everything so it must be CPS, checked the wiring for front sensor and i got continuity from sensor to ECU. Haven’t found rear sensor or its plug so can’t confirm if wiring is good with rear sensor
No spark and no injector pulse almost certainly the CPS. Likely to have other issues also, but one item at a time. Like a mouse eating a piece of cheese. One bite at a time. SD Faircloth
I just want it to fire up for 10 seconds and im happy with my purchase, i can store it and finish my other project.
Took both sensors off today, cleaned them, front one was super grimey with dirt and oil. Still no spark or injectors. They seems to be 300eur a piece, not fun, i think i still need to get my hands on oscilloscope and test them.
Right now i need to find plug for rear engine speed sensor so i can test the continuity to ecu.
Can someone please point me to right direction to find the socket?
Alvar, in the last 3 or 4 years someone had posted about a digital multimeter that includes an oscilloscope function. Pretty reasonably priced under ,$100. Was either in v12 or XJS forum
Checked with oscilloscope, no signal from rear crank sensor. Its called engine speed sensor? Any ideas where i might be able to order one?
There is front sensor available in a lot of places, can’t find rear one, are they interchangeable?
As this is a global website, it would be prudent to let members know where you are located on the planet. Your reference to euros may be a clue…but ? You can click the big green J by your name to make changes.
The flywheel sensor tells the ECU only one piece of information…the engine is turning.
I believe both the CPS and the flywheel sensor are the same. Jaguar part # DBC12507.
Sean is correct. Sensors are interchangeable. Same PN. Front is crank position sensor, rear is engine speed sensor. Both must be working to have injector pulse and spark. If either sensor fails, you will have neither pulse nor spark.
Thank you everyone for information. Im from a small EU country and im used to not having local parts and i order everything around the world so location is no issue for me. I am wondering, since it is a simple magnetic pickup sensor, would jaguar 4.0l engine sensor also work? I can modify the connector and make it fit.
My goal is to make the car run just for a moment to determine the engine is good before i put the car to storage. So the sensor wont be permanent thing.