Now im really mad! A few days ago i noticed a lot of power loss in my 99 xj8l. Like it had only 6 cylinders working. I replaced spark plugs (bosh plat +4), fuel filter and cleaned MAF sensor with MAF sensor cleaner. Right after that car run perfectly!!! Like brand new. I drove it for about 20 miles.Next day,( This morning), however, i could not start it at all. Checked fuel pressure (40 after turn the ignition and then drops to 35). What could be the problem? Any suggestions? Please help.

 

Gregor, check out the FAQ thread in the XK8/R forum (the 4.0 L your 99xj8 is the same as pre-2003 xk8/rs) and we have a few links to help your 'no start' diagnosis symptoms.

good luck!

 

I am new to this site and its a little confusing to navigate through it. THE little i was able to find still did not help. I cleaned spark plugs again, sprayed inside wd40 and still nothing. The fuel pressure gauge is reading 40 initially, at the ignition on, and then drops immediately to 35 psi. is this what it suppose to be? it was running so perfectly just yesterday! what could all of a sudden happen?

 

All right, now I'm reaaaaaally mad! after almost all day playing, checking, asking, calling, writing, reading, praying(!) still nothing. Well, not exactly. I added starter fluid to the throttle body and guess what, it started for a sec. Did it again and again and started every time as long as had fluid in it. So, fuel pump? It does make the humming noise, it does have fuel pressure, it has new filter! so what could be the problem? Anyone? Anyone? Buller?

 

Ok, I started the car. Dont know how, but i did. It wasn't easy. Car did not want to start: was choking, i kept adding starter fluid, pumping gas pedal and litlle by litlle, after about 10-15 minutes of restling finally i got to 2500 rpm, then 3000, 3500. I kept on going for a few more minutes. Revs stabilized and i decided to drive it. It drove well. Took it to mechanic and he told me that symptoms indicated not the fuel pump, as i oryginally thought it would be, but most likely it is catalytic converter. Is he right?

 

At this point I must assume that you experienced a cylinder washing that takes place at times with a nikasil engine. This information might help in your understanding the no start situation. Read it first and see if it applies and we will be open for questions.
http://www.gusglikas.com/AutoRepairNoStart.htm
http://www.gusglikas.com/AutoRepairNikasilSulfur.htm

 

Thank you all for your help. I agree, with GUS. Seems like it was a "cylinder washing". Everything is working well now. Power is restored, car runs smoothly again. Well, semi smoothly. Still have other issues. While changing spark plugs noticed leaking valve cover gaskets, clogged up pcv valve and other things but the main problem has been solved. Thanks again.