Dear fourm

we own a Jaguar XJS straight 6 automatic which was restored around 5-6 years ago in a metallic blue, although we are looking to sell the car we are having issues on starting her... after battleing with my farther to try and get the car to start theres just no luck, refuses to even start on starter fluid... we have checked everything this includes checking for spark which there is after pulling a plug, then we checked for fuel and we can confirm there is petrol getting into the block, this fuel is older but we put around 10 litres of fresh fuel in and this made no luck, we know theres some petrol in the oil but we dont think this is the issue limiting the engine to start, moreover the battery is freshly charged and theres air getting into the engine, we havent tested compression and as a basic learning mechanic i dont know how to test that, if anyone could enlighten me on this i would apprecieate it as i want to get the car started

-Charles

 

Hi Charles

How to Test the Compression

How to Test the Compression on an XJS 6cyl Engine Plus lots of other Tricks that you can try to get her Started

 

just spoke to my dad and he said, the compression would be fine as the car started around 2-3 months ago fine, i forgot to add this to the main post but this is where the issue arroused

the car around 2-3 months as stated above did start fine just ran too rich on fuel, as at the time we didnt know what was causing it we sent it off to a old mate which didnt find the issue but seeming to have caused more issues, right when we got it home we found the issued part which was making the engine run rich and after fixing this we noticed the engine wasnt starting, we checked everything including what i said in the origional post

so yea my dad says its not the compression as you dont just "lose compression like that." without trying to sound smug hes a well knowledgeable mechanic and i trust his word, so yea i also asked about fuel filters and he said they were all good aswell, so would you have any other help for us please?

-charles

 

OK,

You have spark, or what appears to be spark. Probably at a lead, ASSUMMIMG an AJ6 engine with plug leads. Is it a FAT Blue CRACK of a spark, or a washed out excuse???

If its not firing up with Ether, then there is NO spark inside the cylinder, fact.

I suggest a new set of sprk plugs, correctly gapped. All that TOO rich, and now no start, will have basically screwed them. Cheap and will do no harm.

Fresh fuel. I know you put 10ltrs IN, but what was there before?, and stale old fuel simply will not go WHOOSH. Syphon out whatever is in the rank, and start over with fresh stuff. Crack a fuel line connector in the engine bay, TAKE CARE WITH SPILT FUEL please, and purge that old stuff from the line.

I still reckon the old sparkers are simply not sparking, otherwise the Ether would have done something.

 

thats the thing thats confusing us about the plugs, the spark plugs create a blue/white spark and when pulled and cranked... we have tried new plugs and this made no difference just the same old cranking whith no start. for the fuel there was old petrol from months and months ago which we know has gone bad so thats why we put some new fuel in her, we plan on this friday unconnecting a hose and purge all the fuel out the lines and from the tank, then we are going to put more fresh petrol in and see what happens

 

Even if you had bad fuel, you should still get a cough, as long as you had a spark, which you say you have. The only other thing is if there is too much fuel from earlier non-starts. I would make sure I had a good battery capable of really spinning the engine over fast as well as purging any possible fuel that may be lingering in the cylinders by removing the plugs and giving the engine a 10 sec uninterrupted crank cycle. You might see excess fuel spitting out of the spark plug holes during this crank cycle. Then put every thing back and try it. Make sure your cylinder plug wires are going to the correct plugs/cylinders.
Was it running properly at anytime before this episode?..and no maintenance since then?

 

it did start fine just ran too rich on fuel, as at the time we didnt know what was causing it we sent it off to a old mate which didnt find the issue but seeming to have caused more issues, right when we got it home we found the issued part which was making the engine run rich and after fixing this we noticed the engine wasnt starting, so yes it used to start fine, we may try to crank the engine to remove some of the old petrol but i really personally dont think that is the issue as theres not even a splutter when cranking it will just sit there cranking and cranking

 

OK, I'm game.

What was this mysterious part that fixed the richness, but stopped it from starting??

AND

Where are you spraying the Ether??. It must be sprayed AT the throttle body, or as close as possible to the throttle disc, AND that disc needs to open during spraying.

 

I had a similar issue it was a bad starter relay, also check the camshaft position sensor.

 

1. The engine can go zero compression in all holes fast. Ask me, and I'll relate the end of my car's DOHC!!!!

2. As Grant implies, the mate's fix went the "other way". From too rich, but tolerated by the engine, to too lean and no toleration. But that does not explain the no quick fire at the ether injection.

3. You just mitht have a massive vacumn leak somewhere. Tolerated by the extra fuel. but, now far too lean in fuel to overcome the leak.. Even the ether...

Carl