Hi all. Having a hard time starting the engine. Cranks, but won't fire up. I have squirted starting fluid and it seemed to catch several times and after a few more squirts it did. In fact I was keeping it running without fluid but then just suddenly died and won't restart , not even with fluid. It ran before I parked it as it sat for about 6 months. I have located the FP relay over the right wheel arch in the trunk/boot and will be checking for voltage and will jump the relay to test the pump running. Just wanted to know how far to take things apart to get to the pump if I had to and to know where to listen for it running. I thought I heard the pump was external on the convertibles..if any one knows.

Thanks

 

Hi CnP

The Pump on a 95 4.0L AJ 16 is Internal behind that big Steel Baffle Plate in the Boot/Trunk but it might not be the Fuel Pump that's the Problem that is also a King Size PIA to get to

So the first thing I would look at would be the Blue Relay which is just above the Fuses in the Knee Bolster Fuse Box on the Passenger Side of a (UK) Car because if the Blades on that Relay are the 'Thin' Type it might not make very good Contact in its Holder, so try pulling it out and pushing it in again

If no dice then look at this Thread, where I try almost every trick in the book to try and get my AJ16 4.0L Engine Started and eventually succeed!

Also don't discount a lack of Fuel, as 10 gallons of Petrol might not even be enough to cover the Pick up Strainer on the bottom of the Fuel Pump

'Carmen Won't Start' Trying almost every trick in the book to get my AJ16 4.0L Engine Started and eventually succeeding!

 

Thanks OB. Actually, the fuel level has been on the back of my mind as she sits about a 1/4 tank at the moment. I have had it a this level before so I wasn't paying too much attention to it, but I may just put 5 gallons in it to eliminate that doubt.
According to the electric guide/diagrams, the FP relay is in the rear over the RH wheel arch, which I believe I have found along with several relays parked in that location and with a yellow base as referenced in the WD. The other relay and fuses are in the knee bolster RH front on passenger side USA car. I have found that one too and that relay is called the Engine Management System or "EMS" power relay, which supplies power to one side of the FP relay coil. The ground of the FP relay coil is controlled by the EMS. At the moment. the related fuses look good, so now just have to check to see if power is getting to the pump.

 

Hi CnP

Having been there and done it myself, not enough Fuel in the Tank would be a Prime Suspect

Although worst case Scenario, if the Fuel Pump needs Changing icsamerica has found a way to do this without pulling the Tank right out but even so removing that Baffle is a real PIA Job and that Boot/Trunk lid weighs a Ton with the Gas Struts removed

Also Check the Fuel Pump Cut Out down by the Door Pillar, just in case it has Tripped

Good Luck

Alex

 

No luck yet. Seems I am getting fuel, at least on the first key turn as I removed the fuel line form the rail and put in a bottle and turned the key to position 2 and saw fuel coming out. Turned key off and repeated, fuel came out again. So I don't think I have to go digging to find the pump anymore. I also added 5 gallons of gas.
Checking for crank sensor info, she does indicate movement of the Tach up to around 200rpm while spinning the engine over for a start...but no joy on the fire up.

 

Hi CnP

In that case I would then pull all the Spark Plugs, as they may be either Wet or all Coked up

Give them a Clean, see if they Spark and then try her again

Also looking like it could be blocked injectors, so it may pay you to knock up a rig to test them as apart from a New Fuel Pump, Blocked Injectors was the reason my Car wouldn't Start, as they seem to have a little bit of a Shelf Life if you haven't used the Car for a while

 

Alex,
So, I pulled the plugs. Weren't too bad. I don't think its the injectors because when I had her running for a very short time, it was running smooth and idled just right, but then out of nowhere, it would just quit..as if some one shut off the ignition. Attempting to start right after she quits , no dice.
I will tell you this though, and I don't think this has anything to do with it but last year after I washed the engine down with de-greaser and a good rinse, she would not start up. I believe at that point, I may have had water in the spark plug wells. I let it sit for a few weeks before I could get to her again and she started and ran, however, the alternator was not working. Six months go by and just getting back to her now, I put the charger on the battery and attempted to start again. Same..spins but no fire. After several more attempts with starting fluid, she fires up and runs fine, smooth and idles. Mind you, she is not charging back the battery as there is no output from the alternator, but I am keeping the batt powered by the charger while engine is running. It is not 14.5 Volts but the car's voltmeter is only showing about 10 or 11 volts. The charger I have on it doesn't see to be keeping it at 12 or above while engine is running for some reason. Could this be the reason for the untimely shutdowns? I may have blown the alternator when I washed the engine down last year. I did a diode check on the diode pack and all of them seem to be shorted. Guess I'll get the alternator fixed first. It never sputtered to a stop as you would think that would happen if a lack of fuel or injector issues. This is why I think this is a power or voltage problem. it just shuts down like you turned the key off and hard to start afterwards or no start as the case is now.

 

Hi CnP

Each of those Spark Plugs has its own Separate Coil and so with getting water down those Spark Plug Wells, there is a possible chance that you could have shorted one or more of those coils out and so I would start by removing the Plugs and then checking through them one at a time for a Spark

 

So back to the no start problem.
So far:

• Fuel pump runs for a few seconds in ignition switch "run" position, then stops. Turn key off and back to run, and same thing. I assume this is normal to prime the system before start. With this observation, I assume there is nothing wrong with the pump. I removed the inlet fitting to the fuel bar and placed in container to watch the fuel output when trying the above checks. Question: Does the pump run during the "crank" position too?
  • I assume when the crank sensor is happy, the ECU will allow fuel to pump continuously in "Run" after it starts.
• With starting fluid, it does cough a little and several start attempts before, it would start and run smooth, but then as I mentioned in an earlier thread, it would quit after a few minutes of running.
  • Is this behavior indicative of a faulty crank sensor? If loss of pulse signal, I assume it would kill the fuel too. Maybe this is what is happening.
• I have not checked for spark at the plugs during any of this cranking activity. I guess a spark or no spark would tell me the crank sensor is the culprit. But then why does it cough with starting fluid if that were the case of a bad crank sensor?
• How do you remove the crank sensor black connector connector from the bracket. Not the the sensor itself, but the black disconnecting connector. I've separated the mating parts but the fixed portion is still attached to a bracket of sorts on the engine front just under a metal water pipe.
• Does anybody know what the resistance should be of the crank sensor if I am able to probe the connector pins?

Thanks

 

Hi CnP

The 'Link' below will show you how to remove the 'Crank Position Sensor' and or 'The Plug' you were talking about although it is much easier to remove the whole thing including the Bracket and then Separate the Plug from it once it is out of the Car, as the Electric Plug on the CPS is one of those where you squeeze the sides

Where as such separating that Plug can be a PIA Job, unless of course you get lucky and can manage to squeeze the sides of the Plug enough to separate it, which I found was easier with the whole thing out of the Car, although which way you do this is entirely up to you

When you turn the Key to position one, the Fuel Pump just activates for a couple of Seconds but should pump continuously when cranking, assuming that the Fuel Pump Relay is working, which is in the Boot/Trunk near the Gas Strut behind a piece of trim and right underneath the Fender/Wing, so is quite hard to see (The Silver One)

(Side Note) The Pump should run Continuously if (A) The Engine is Running or (B) When Cranking 'if' The Fuel Pipe is disconnected in the Engine Bay, where a Tube would be put over that pipe and then hung over the Fender/Wing to catch any Petrol in a Container which is outside the Car (To avoid a Fire)

While it could be the CPS if She runs on 'Starting Fluid' then it would seem much more likely that one or more of the Injectors has a Blockage or you have a faulty Coolant Temperature Sensor, where you could Bridge the Socket that goes on it, with a Paper Clip or piece of Wire in order to Test it

But if the 'Taco' Needle Flickers, when you Crank the Engine then that is an 'Indication' that the CPS may be ok

As another Side Note: To anyone else who has a problem with the CPS on a 4.0L Six Cylinder XJS Changing it is one of those jobs you could do by the Side of the Road in just a few minutes, if you carry a spare one in 'The Glove Box'

With Zero dismantling involved as you don't even have to remove any hoses (which is so much better than having to phone for a 'Tow Truck')

Good Luck hope this helps

All about 'The Crank Position Sensor' including removal which is very easy once you know how

 

So...I just confirmed (and probably should have done this test before now), that on ign sw position II, I do get a brief flow of fuel as mentioned earlier, but the next test was to see if I was getting fuel during the crank phase...I am not. I did not test for this before because I was sure the pump was working due to brief priming at position II. This would tell me the FP relay , pump and associated wiring was good and assumed that if pump was working in Position II, then it should be working as well in the "start" position during cranking as well.
So, ..., where does the signal come from to allow the pump to pump during the crank/start cycle? Ignition switch?, ECU?, crank sensor?
I feel I am now on to something but not sure what.

 

Hi CnP

It could be the Fuel Pump Relay, which is in the Boot/Trunk by the Gas Strut behind a piece of Trim right underneath the Inside of the Wing/Fender

Hard to get to and even harder to see but it is under there and its Silver

The other possibility is a Faulty Fuel Pump though hopefully not that

When you turn the Key to position (1) the Fuel Pump should activate for only a couple of seconds and then turn off of its own accord and it should do this every single time you turn the Key ON and OFF and if you had the Fuel Pipe to the Fuel Rail disconnected

With another Pipe over it, hanging over the Front Wing Fender into a Container to catch any fuel, then turning the Key ON and OFF should pump Fuel every single time

But having said that do not discount that you may not have enough Fuel in the Tank, as on these Cars you might need in excess of 10 Gallons to even cover the Inlet of the Fuel Pump Strainer

 

Yup, thanks. I had located the FP relay a few threads ago and because I am getting fuel to prime at position II, that tells me the relay is powering the FP, at least at position II. I have a clear tube attached to the fuel inlet fitting and overboard to ta clear container. When turning the key to position II, I can see the pump does run/prime as it should for a few seconds. However, when I continue on to the start position, the FP does not run during the cranking phase. This lack of fuel pump action during cranking would certainly prevent a start and would explain that when I shoot starting fluid down the intake, it briefly coughs and sometimes actually get it to run until it all of a sudden quits. This is what has been happening.
The question is, what is supposed to allow the FP to run during the crank cycle and why is it not happening. Somebody can chime in, but I think for fuel to pressurize the injectors during the start/cranking phase, the ECM needs to know it's getting good firing pulses from the crank sensor in order to introduce fuel. I put a wrench on the sensor magnetic tip and it held so seems the magnetic pick up is good, but I couldn't easily get to the connector pins after I separated the two connector halves so I couldn't measure to see if the value was correct. I don't even know what the value is supposed to be for a good CPS. Anybody?
To continue to troubleshoot, I would like to know if the CPS is directly responsible for the turning on of the FP during the crank cycle. Oh, and when cranking, I do get pulses on the tacho. So that kinda tells me the CPS is working so is there another device or connection that is not happening that would prevent fuel pump action during cranking? Ignition switch?
I also added gas 5 gallons which brings the tank to 1/2.

 

Hi CnP

It could be a bad Fuel Pump Relay or a Problem with the ECU or even the Coolant Temperature Sensor not working as it should or a dodgy Fuse for the ECU which is one of those inside the 'Kneepad' Fuse Box or one of those 2 Blue Relays which are above it, where the blades are not making very good contact

'Doug' is also helping someone with a similar problem, see the Thread: Intermittent Fuel Pump

 

Thanks,
I did locate and look at the two blue relays that you referenced. They are the Engine Management System,(EMS) Power Relay(white base) and the ECM controlled relay(Blue base). It looks like the EMS power relay is what it is titled and seems to power the computer and prepares/supplies the fuel pump relay with 12V when you turn the Ign switch to position 2. This is the position that readies the engine management as well as gives a brief prime. The brief prime signal is given by the ECM at each power up into position 2 and is the ground leg for the fuel pump that already had power waiting as mentioned above. ...and because the fuel pump is priming, that tells me the the relay that controls it (EMS Power relay), is working. Now, the question is during cranking and running, a new signal is sent out from the ECM on the same ground leg to power on the fuel pump relay to power the pump. Something is needed and should be telling the ECM that all is good with the engine and ignition signals in order to provide that crank and continuous run ground signal to the fuel pump relay. Is it the pulses from the CPS that determines it? Or what... I can't see what is going on inside the ECM that would be needed for the ECM to output the needed ground to the FP relay during cranking and Run. I am still suspecting the CPS or communication to the ECM possibly. Can't be from the ECM to the FP relay because it the same ground that is supplied during prime, which works.
So the saga continues...

 

So, quick follow up and new issue.
From my original post question, after almost a year of sitting, which is quite common in my driveway with 4 or so cars sometimes, the Jag had difficulty starting. Once I did get it running, I noticed the alternator was not producing voltage. This all happened actually just after I decided to give the engine a little bath. I didn't try to start it just after the bath, but tried a week later. That's when the alternator seemed to quit. I then could not get the engine to start at this new attempt. Kept having to place a charger on the battery to keep the volts up as I continued to try various methods of starting. Starter fluid helped to start but quickly would die if I let it idle. Thinking fuel related, asked the forum where the FP relay was to try to jump it. Time went on with more attempts including looking at the plugs and other areas. ( I broke the ceramic off of one plug while removing it so I replaced it with a spare plug I had sitting around. No idea what car it came from , only that it could have been from one of my other cars, BMW or or Audi) No dice. Resolved to the fact I should try a CPS. Replaced the CPS and alternator and it started right up. Idled now on its own and everything good. However a new issue. Took the car on a quick test drive and no power going up hills back to the house. I guess I took a chance driving half a mile slightly down hill and quickly realized it was missing going back home up hill, almost didn't make it.
So, the question is, will the ECM shut down the injector or all injectors if a miss is detected? I read on a recent post that will happen. If that one odd plug were bad, would that cause what felt like a no fuel issue to all the cylinders, the only way it wold run reasonably well is when I let my foot off the gas, then it would seem like it would regain some level of power, but as soon as I put my foot down to climb the shallow hill, it would bog. I kept having to regulate my foot pressure to sustain any form of power to climb.
Any thoughts? I have not replaced the plug with the proper one yet, but I haven't come across this kid of power loss issue with just one odd plug installed before. I could see a miss of one cylinder where it would run on five, but to have no power at all with throttle opening was odd.

 

Hi CnP

It could be the Coolant Temperature Sensor, if that's not working properly your Car could Over Fuel and then bog down

Try the 'Paper Clip' Trick and see if that makes any difference

Testing to see if the Coolant Temperature Sensor Works with the 'Paper Clip Trick' although if your fresh out of 'Paper Clips' you can use a Piece of Wire which Fools the ECU into thinking that the Injectors have got enough Fuel and so prevents Over Fuelling

 

You would get a code if any of your cylinders were not firing. These engines are stingy with codes, but I think a non-functioning code, or coil would indeed provide you with a code.

Are you absolutely sure that the coils were plugged back properly? It is possible that you swapped the plugs for cylinders 5 and 6?

I doubt it would be the Coolant Sensor. That leaves the car in open loop and, if anything, will give you the sensation of added power.

 

Thanks OB, I'll give that a shot. Since owning the car the last three years, the coolant sensor never gave me any problems, so wasn't looking there at first. The wiring to the connector looks a little dicey actually. I'll put that on the top of the list.

 

Thanks Vee. As mentioned, it now starts and idles fine and seems to be free revving while stationary. And I did take care to mark 5 and 6 as they could become swapped as you say. Prior to the first start after the replacement of the CPS and alternator, I did take the air cleaner apart to give it a good cleaning when putting everything back together after taking that and shroud off to clean the area of debris. I was also trying to investigate why the fan wasn't going into freewheel after the temps were up, thinking the bimetallic spring and spindle were stuck, so that's why I had the fan off. I'm pretty sure all was back together properly even double checked it. Could I have left a connector off, hose, etc that would affect throttle outside of idle?