I drove my 93 XJS V6 3 days ago and it ran well (48k miles). Now it will not start. The ignition turns on and starter engages but it won’t fire. Not even a sputter. I have a quarter tank of gas so fuel is not a problem. No fault codes thrown. I’m thinking it might be the fuel pump. Any thoughts on what to check? I am a do-it-yourselfer and hate to have it towed to the dealership only to find it was a simple fix that I could have done. Any help would be be appreciated. Thanks.

 

You should be able to hear the fuel pump running for about six seconds after turning the key.
Common issues that can be checked easily are inertia switch, fuses, especially the HO2 sensor fuse.
There is no such thing as a 93 XJS V6.

 

Possibly the crank position sensor went out. First thing id do is check fuses to see if any blew out. Unless its a v6 conversion at which point itd help to know what engine is in it

 

If it’s the original stock 6 cylinder engine, you do not have a “v6”. It’s an in-line 6. Just refer to it as the 6 cylinder engine, or the AJ6. A v6 may confuse someone into thinking you might have put in a Chevy crate 6 cylinder “v” engine…..which isn’t very common, but it’s probably just a tick more common than rare.

 

Hi Drewman

The First thing to do is to Check to see if you have a Spark

If Yes, then its Fuel Related

If No, then its Electrical

Since you have an AJ6 Engine and Not an AJ16 (which has Separate Coils for each Spark Plug)

Start by Removing one of those Spark Plugs and laying it on Top of the Engine while it is Still Attached to its HT Lead and then Spin the Engine, where you will either see a Spark of Not

If No Spark then Check the Coil and also Check the Spinner in the Distributor

As mentioned it could also be a dead Crank Position Sensor

Or Water may have Trickled down inside the Cabin Trim and Corroded or even destroyed the Pins in the ECU

Also Check all the Fuses and also check for Corrosion on the Pins of the Blue Relays above those Fuses and make sure those Blades are a Tight Fit

It could also be the TPS on the Throttle needs adjusting but best Speak with Grant 'The Wizard of Oz' about that

If you do have a Spark then it could be Fuel Related and Maybe the Fuel Pump Relay needs replacing, which is awkward to get at as it is right underneath the Inner Fender/Wing in the Boot/Trunk which is the Silver one

You also need to check to See if Fuel is getting to the Fuel Rail and that the Injectors are 'Clicking'

Also have a look at my Thread: Carmen Won't Start where I tried every Trick in the Book to get my Engine Running, as I eventually did

Let's just hope its not the Fuel Pump as replacing that can be the Job from Hell

My Engine is an AJ16 but as they are very Similar the Thread below might give you some ideas

Good Luck and let us know how you get on

Alex

Carmen Won#t Start How I tried every Trick in the Book to get my XJS 4.0L Running

 

Top advice Alex: I quote
The First thing to do is to Check to see if you have a Spark

If Yes, then its Fuel Related

If No, then its Electrical

It should be written out, framed and fixed on every classic car owner's garage wall!

 

Hi Greg

I'm not taking any Credit for that, I just tried to remember what you and Grant told me to do as its always worked for me and no doubt others too

 

Thanks for the info. Yes.it is a 4.0 L inline 6. I’ll start with the spark then move on. Much appreciated.

 

One thing my 93 had too, was that on the ecu, there are yellow and blue connectors. Mine wouldnt start and by dumb luck more than anything, i found that if they were just sitting there,, every once in a while it would shut off and not restart. However if i put something between them, i used a piece of heavy foam mat, it would start and run perfectly! And has been for 3 years now! Someday ill get another one, but I couldnt see what exactly was wrong with mine, probably a soldering issue, but its not really high on the list of things i feel i need to do.

 

Well I will be a little contentious here and say that spark outside the combustion chamber proves only that the car can produce a spark. it does not prove a 'good' spark nor the plugs ability to deliver the spark under high pressure, plugs degrade over time, it isn't just the spark gap.

A sure way to test spart is 'easy start' or some sort of volatile aerosol - if the car will splutter or even start with that stuff sprayed in the intake the spark is proven.

How often that thought process has bitten my ***. In the tank doesn't mean it is getting where it needs to be ....