1994 xjs won't start

I have a 1994 XJS 2+2 convertible=le that ran until I decided to pressure wash the engine etc. I sealed all ignition wire etc. with plastic film and tape, disconnected the battery and then washed it. Before I removed the plastic and film I replaced the power steering fluid reservoir. I then reconnected the battery and attempted to start the engine. No go. I checked the spark and their seems to be ample. I assume that the timing is OK and I have compression as the engine does not over-crank. I do hear what appears to be the fuel pump run and turn off after a couple seconds. HEPL!!

Hi Richard, before you washed the engine did you run it for a while or just to move it a short distance?
I don’t know if you have the V12 or I6 but sometimes the computers can get upset by a short run. Have you tried flooring the accelerator and cranking the engine? If it is flooded this cuts off the injection and allows the cylinders to clear (on the I6 at any rate)

Robin, thanks for your reply, yes the engine was running smoothly. Also, I rechecked the ignition at a plug (#6) and found that it was there, but possibly somewhat weak.

I used to dread the tow truck after the customer came in with a sad story of washing the engine. No sympathy really but it would cost the customer even if it was under new car warranty because the Jaguar warranty does NOT cover deliberate damage to the electrical system.
Many years of people doing this and they finally issued a guide.

Jaguar info for you.

600-02 Pressure Washing.pdf (26.8 KB)

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If that’ 4litre the only thing that can be strucked with your washing fun would be crank pos sensor. Just unpin the plug and check. Just wondering, where did you get the idea of jetwash the engine. Your jag retains valuewhile greasy and covered with oil…

Richard I maybe didn’t express my question correctly, I was asking how long you ran the engine from cold before you turned it off to power wash?

Back in college I was a co-op student at a power plant. There was enough soot coming out the stacks and falling on the employees’ cars in the parking lot that they installed a little car wash on the drive out of the plant. If the soot stayed on a car too long, it’d damage the paint, so it was wise to use the thing. No soap or brushes or anything, just a bunch of spray nozzles with really high-pressure spray. So this one guy had a Porsche Carrera with mechanical fuel injection, and he pulled into that thing, it started spraying, and that was the last time that car ran that afternoon. No, the hood was not up. The guy later grumbled that thing was localized monsoon. But then he took to waterproofing his ignition system, applying sealant here and there, and testing it until he could get through that car wash without stalling.

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Robin, the engine hadn’t run for several hours and was cold when I pressure washed it. Thanks again for the concern.

I had the same problem, no start after pressure washing engine. I used a small fan heater inside the engine bay to help dry it out, but it was still a couple of days before it dried out enough to startup again.

There was a time that I washed my engines with water and other goops. At times, i had to resort to drying measures to get them to start.

The vacumn cleaner at the DIY was station aided in the dry process.

Once I got my first FI car, I stopped that practice.

Way back when I earned never, ever to wash the engine in our family 38 Dodge. The HT wires were encased in a steel shroud. Caught even spit!!!

I’ll try again, before you washed the car did you start the engine and only run it for a very short time i.e. not up to temperature?

Robin, the xjs hadn’t run for a couple days before I pressure washed the engine, so it was cold. I waited for several hours, at least 12, and then tried to start it, to no avail.

I’m sorry Richard but that still doesn’t answer my question. The last time the engine ran how long was it run for??? 1 minute, 10, 50?

Robin, The last time I ran the engine, it was for only a minute or two and that was after its battery mysteriously went dead and taken out of the car, recharged, installed back in the car and and then tested by starting and running the car for a minute or two. I don’t know why the battery was “dead” but it accepted a charge and now seems to be OK.

“Sometimes it is the people who no one imagines anything of who do the things that no one can imagine.”
Alan Turing

(Attachment Richard Lassiter.vcf is missing)

Robin, the more I think about it, I can’t really remember if I started the XJS after the battery was “charged up” again. Probably not. I now believe that I only attempted the start after the power wash. I do remember that the XJS ran around town for an hour or so and that I parked it hot in my garage. It was a day or so later that I discovered that its battery was dead. I hope this helps. Thank you for your help!

From my previous post


Your alternator.
You’ve drowned the bridge? Probably you have Bosch 115amp is that right? It explains why your battery went dead (your alternator has power supplied all the time, with ignition off)

Hi, the battery went dead before I power washed the engine, etc. Your comment about drowning the alternator may well be true, but it now has been four days and the should have dried out by now. Any, I still haven’t figured out what’s going on.

Robin, the XJS has the 4L engine. I do now remember that when I initially tried to start it, it seemed to at first want to start and then just cranked. Also, I did smell fuel after this attempt, but not so since then in any of my further attempts to start it.

So have you tried what I suggested?
IF the engine sounds like it is spinning over quicker than normal you need to drop some oil into the bores.
If it sounds about correct then try flooring the accelerator pedal to cut off the injectors and while still held down crank and keep cranking until it fires.

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