Hi All! im new to the forums and this will be my first post!

I have an 87' 3.6 XJ40 which just does not want to idle or move. a week ago it ran perfect never missed a beat perfect to drive everything good. Then we had some heavy rain and she did not want to move, cleaned everything out and sprayed some contact cleaner around and she started up again and drove fine. I decided to wash it sheepishly to get some of the grime off and behold, it does not want to move again.

I have cleaned out everything once again and put new spark plugs in it, checked my dizzy cap and the leads, coil, all fine. I've heard it could be the crank position sensor or the O2 sensor, or even the Air Flow Meter (i hope not!)

As of today she starts very unwillingly, lasts a few seconds sounding rather sick, and dies. Any Ideas?

Thanks!

 

Could be one of the things you mention above.

Have you also checked the electrical connections at your fuel pump, maybe you blasted something loose. (under the left rear arch).

Dirty throttle body, the big rubber bellows seem to trap crud. They could also be split.

Also check vacuum lines.

And battery condition/connections.

Just a few things from my limited experience.

Others will add.

 

Thanks for the advice ill check in the morning

 

My opinion, only based on experience. You said "rain." That's all I needed to hear. Where that gas filler cap is on that car is just inviting water in that tank, sometime, someday.
If you read my past posts, I spent countless hours of diagnosis, replacing components 2 and 3 times, dissecting wiring schematics to only realize I had water in my tank. Which after several 100 cranking attempts put water throughout every part of the combustion process. Please do yourself a big favor and check for water prior to going crazy.

 

Welcome, creatious:
Most certainly, don't panic - and start with the easy/cheap possibilities. If there were problems with some of the things you mention, it seems to me that you would have poor performance: not NO performance. So... spark and fuel. Double check the dist. cap is seated perfectly. I think if the CPS has gone bad, it wouldn't fire at all. I suppose it could be working intermittently... There is a process to remove it and test it with a meter. Try an archive search to check into that. (I've never actually done it.)

Once you are sure you are getting spark, you will need to begin whittling down fuel-related possibilities. When I once had stalling/starting problems, it turned out to be a $10 fuel pump relay. Offhand I do not remember where that relay is located in your '87 - probably under the hood like mine.

Just some thoughts. Let us know how it goes!
Scott

 

Okay new diagnosis:

When i turn her over and keep my foot on the accelerator she will stay going but sounds very bangy and clunky. as soon as my foot is off and the revs are gone it dies. i put some cleaner in my tank for the water but if its a lot of water im going to have to clean it out.

 

Sounds like you are on the right path. Drain the tank from the input side on the fuel pump. Be patient, it will take awhile to rid the water from every component that has been affected by it.

 

Change the fuel filter too, it probably couldn't hurt. Also check the ignition amp near the coil

 

It took me at least 5 to 6 days to get my car to run after having water in it. Even after that for at least 3 more days my CEL would come on indicating a problem with the O2 sensor. Another 2-3 days driving even cleared that up. It's been about 4 weeks since then, the car has never been smoother. Water is a killer of cats and Jaguars.

 

Theres no water in the fuel filter, The fuel filter has been changed, air filter and new dizzy cap. It starts and runs with the foot down and you can hear her backfiring. wont idle but if your foots down it will stay running. as soon as its off its gone.

Its igniting fine so its not an ignition problem, which rules out the CPS and surroundings.
Im looking at a fuel problem or fuel relay. but at the moment my manual isnt helping at all and im all out of ideas.

Its got fuel pressure and as of just now it will idle and sounds clunky. Perhaps a timing sensor?

 

I'm having the same problem - have you found a solution yet?

 

Found the problem. i replaced almost everything in the vehicle.
But the problem was water in the fuel injection and body management computer. this is located in the footwell of the front passenger seat. when we removed all the water we had to fix up some resistors and clean some terminals and it was good as gold!

This is why everytime it rained the vehicle wouldnt start. If your looking for parts in australia jagspares.biz are excellent.

 

Good news, thanks for your update
Happy trouble free starting

 

Excellent. Rain/water great for frogs and ducks but definitely not cats.

 

Good news indeed.

Did you discover how the water was getting in?

Slightly Off Topic, in over 20 years of living here, I have never seen a frog, toads yes, but no frogs.

And no, we didn't eat them all.

Wonder where they went?