Hello, I have a 1997 XJ6 with a 4.0 6 cylinder and I've had the car from 4 or so years. I bought the car as not running and figured it out as a bad crank sensor. I had also replaced the Throttle body and cam sensor. The car ran really smooth afterwards. I then took the car apart to do subframe repairs. The car then sat outside for 2 or 3 years and never touched. Now just recently I decided to get it going again. I had tried to start the car and it only cranks over I then check Spark and Fuel. The car had Spark but the noId lights showed the injectors not firing. I then assumed another bad crank sensor as the car has same symptoms as the first time. I then replaced it with a new one. Still no start. It will start on starting fluid but that's it. I have fuel presure, spark, fuel pump is good crank sensor tests good and I have NO CODES. I have been pinpoint testing and still can't find the issue. I have tested the new crank sensor, wires from sensor to the ECM, then wires from ECM to injectors. The ecm has slight rust on outside but nothing inside. I have also tested TPS, Cam sensor, MAF And still nothing. Please HELP!!!

 

How long has the car been left unused? A good start would be to clean all ground points, check all fuses and relays, and find a very strong battery to really crank the starter and move the flywheel. If you read my posts about Rose which was dead for three years, water in tank, fuel lines, soiled injectors, corroded ECU, loose wires, and surface rust in starter and the engine were what were stopping the engine from firing up. Hopefully, your cat's problem is less complex than mine.

 

I read somewhere on this forum that as they sit for a while you pull the plugs and fill the cylinders with a bit of engine oil and let it soak for a while ( time ? ) . This restores the piston ring seal so you have the compression for engine start . Rislone or similar engine oil treatment in my opinion may be a better option as it unsticks the rings and they may expand better against the cylinder walls . Yep it's going to smoke until it burns out . The spark coils get there power though the troublesome corroded PI - 1 connector , the white one below the windshield washer fluid cap on the car frame rail . The wire is the White /Pink one in the # 4 position . Ref. Wiring Schematic figure 4.1 . You can jumper around it or pull power from the terminal post of the nearby R/H engine bay fuse box to give you a stronger spark . The ECU provides the timed ground for each plug for the current to flow for spark . Suggest check one of the grounds is the ECU aft attach bolt that has the black wire attached . The injectors get there power through the PI - 161 connector with the Black / Light Green wire in the # 1 position . The ECU then gives the timed ground for each injector pulse . I beleive the PI - 161 connector is the black one next to the PI - 1 and should have similar corrosion issues . The splice is under the plastic cover above the fuel rail but all my splices are in excellent condition . One of the neglected engine to frame grounds is located by the starter that is the woven wire type . I don't know how this would relate to your symptoms but if you wanted to cover all the bases on your grounds this is one. I am a fan of cleaning the grounds as a scheduled basis . Hope this helps .

Thanks , Parker

 

The fact that she will run on starter fluid is a big positive. I would try replacing the fuel, as modern fuels have a distinct shelf life, and after sitting for a few years can lose the ability to fire the engine. As has been mentioned, water in the fuel is another possible consequence of being laid up for so long, which would exacerbate the problem.
I would treat her to some fresh fuel, and see what happens. Worth a try, and doesn't do any harm.

 

You say the fuel pump works, but how did you check that? Is it really delivering pressure to the fuel rail?

 

I myself could not find any proper fittings to thread in a fuel pressure gauge . So I drilled a hole in the fuel regulator out port hex-nut and epoxied in a tiny copper tube ( hobby store ) and a gauge from a air pump . Not by any means a perminate installation but it's the best I could rig up without compromising the harder to source fuel rail . Later I'll replace the tube with a sealed machine screw . Note for TheRealMann1219 on the fuel pump sequence is that it primes the fuel rail for 5 seconds and then turns off . After the ECU sees engine rotation ( crankshaft sensor ? ) will it command the pump to turn back on . You my have seen trapped residual fuel pressure and not true " run " fuel pressure commanded by the ECU . 43 PSI. You can listen or feel for the pump sequence with the trunk open . My pump works fine plus the proper pressure . Yes on the above recommended old fuel replacement but my fuel was fresh and not an issue . Mine was electrical and starts fine now .

 

A former X300 lover permanently installed a fuel pressure gauge to the fuel rail to help reveal if fuel pressure is normal in case of no-start. See middle of his write-up
Jaguar XJ6; Jaguar X300; Engine Control Unit; ECU

 

I have checked voltages at everything for the fuel system and everything checks good. As for fuel pressure I put a 2 litter bottle at the end of the fuel rail and disconnected the fitting and cycled the key and it sprays fuel at the correct rate I'd assume from working on other vehicles. I have cleaned the fuel tank 3 times and flushed the entire system 3 times it's definitely not a fuel issue. I have diagnosed it completely to the point I do not have a injector pulse coming out of the ecm. I have replaced with new crank sensor and it tests good and the ecm is getting a signal from the crank sensor. From all my tests the car should run. I have spark, and signal from the crank sensor. Iv checked the inertia switch and it's working fine. I have opened the ecm and there is no sign of damage. The ecm is not telling injectors to fire.

 

A mode of failure with a relay that will show voltage but can't carry the current to run the device . Called a cat whisker or a pitted contact . I used a Aircraft landing light that requires alot of current to run bright comparing it with a known good system to see this . With not being available to you ( modern Car headlights are questionable as to whether you can see this ) I would recommend swapping the ECU relay with the headlight or fog relay and the fuel pump relay with the nearby accessory relay . Another mode of failure is a floating contact where the over center and clamping spring is broken . You can simply tap the relays with to handle of a screwdriver and see if that does anything for you . With your finger placed on a relay you can feel as a thump the pulling coil operation but this does not say anything about the quality of the relays power through contact . As with to fuel pump relay you should feel a second thump in the start to run sequence as it pics up a rotational signal that the ECU sees to start the pump again as you have the engine running at that point . Check the condition of the connector that the fuel injectors get their single source of constant power from for the firing coils are ground seeking commanded by ECU through their 6 wires . What I found on mine was that since the RS3 ( fwd of ECU ) connector was damaged not allowing the fuel pump relay control signal # 22 Pink / Brown wire ( pulling coil ) to get back to the trunk the previous owner had utilized the nearby trunk accessory relay ( not controlled by the ECU but controlled " on " with key " on " ) with a very poor pump power wire twist splice . The cheap electrical tape glue had migrated through the years into the treads of the wiring contact surfaces causing poor contact and the power to the pump to be intermittent sans engine . Had to rebuild by bypassing with environmental splices all the wires around the RS3 connector ( connector was damaged beyond repair ) to get back to the original factory configuration and transfer the power wire back to the proper pump relay . Pump works fine now . The LS3 connector is next but down my list . The accessory relay can be utilized but with a proper splice practice . Try the relay swap first .

Hope this helps .

Thanks , Parker

 

You do not have a location set. This will not be relevant if you are in the USA.
North American cars only have a security alarm and crank inhibit. Cars in the Rest Of The World have an additional security immobilising function that inhibits fuel injection. The ignition key contains a transponder chip that is read by the Security and Locking Control Module (SLCM) using an exciter coil fitted around the ignition switch. If the key is accepted an encoded signal is set from the SLCM to the ECU and injection is enabled. See Fig 0.32 in the wiring diagram for an overview.

 

Figure 15.4 ( ? ) of the Rest of World wiring diagram , Coil of the Column Switchgear of the middle right hand side of the print controlling the fuel inhibit to the ECU by way of Green / Black wire through the Papa Indigo 63 connector ? Suggest reseating of the SLCM connector locking arm securing to the lock position with a tie wrap . Carefull not to bend any pins or breaking the locking arm post on the SLCM side of the connector . Mine does not have a very good " feel " to it as it closes and makes me sickish as I reconnect and secure it . My SLCM connector in North America is of the single same as the RS3 connector not reflected in any SLCM print . If the subjects car is the same as mine the connector locking arm migrates to the unlock position losing wire contact immobilizing a start . Suggest also check the Security System fuse trunk # 4 ( 4th from the power terminal post ) that immobilizes a start .

Thanks , Parker