The car isnt being driven regularly while I'm on holidays. So far its been twice out of the last four starts over the last week and a half.

The car; 2003 AWD TJ Sports
The conditions; Queensland erratic weather - wet/dry/humid/hot
Car is parked undercover in a car port (no sides)

First start was after being left on the car ramps for a few days while I was under there measuring stuff. This was front wheels up on the ramps, bonnet down the whole time. It was there for maybe three days?

Second start was quite a few days after, with one good start between this failed start and the last. Car was parked level.

The only common thing is the fact it was raining heavily prior to these two starts. What doesn't make sense is the other two times its started easily after, and even during, heavy rain.

The first failed start-up was the worst. This was after being on the ramps for a few days. Car wound over fine, no sign of a flat battery, but there was no hint of ignition for a while... maybe six attempts of cranking it over. When I was getting life, it was short, spluttery and weak. Sounded like it was flooded? Attempts after than seem to bring one cylinder to life at a time until I finally had it running on all six. It didnt sound good :( Eventually though, it came good and the car was back to normal, driving well and strong.

Second failed start was the same thing, but not as dramatic. One or two cranks and it came to life... one cylinder at a time before setting to an idle.

I haven't had to do any work on the engine in a long time, so I dont think I've upset anything in there. My measuring, under the car, was to model the sump/k-frame etc... didnt see any obvious build up of water under there. Inside the car is dry and doesnt smell damp. No new electrical do-dads installed recently, no major mods or hacks performed, no major bumps/crashes or knocks. Nothing for me to start with essentially. I'd prefer not to start getting down and dirty unless I have a good idea of where to start.

The car is probably long overdue for a fuel filter replacement... could this be my issue?

Any pointers much appreciated.

It could very possibly be a blocked fuel filter, when was it last changed?
Have you also checked your air filter recently?

Checked the distributor cap for cracks lately? Sounds like some condensation inside the cap.

It could very possibly be a blocked fuel filter, when was it last changed?
Have you also checked your air filter recently?

Air filter is new. Unsure of fuel filter, so I purchased one when I first bought the car.. should probably do that regardless.

Checked the distributor cap for cracks lately? Sounds like some condensation inside the cap.

ah hah! something I can check (should have checked).... off to have a look now.

just a random throw out, but being on stands the fuel system may have bled back to the tank taking some time to re-pressurize the fuel system, hence 1 cylinder coming to life at a time as the injectors receive fuel.... may have a dodgy fuel pump?

Okay. I had a quick poke around in the engine bay - couldn't see anything obvious. Distributor and leads look good. Everything was a little dusty, so I hit everything with contact cleaner. Took the car for a decent drive that day and it seems to be back to normal now. Mind you, most of that day the fuel economy was horrendous.

I'll replace the fuel filter and have the injectors ultrasonicly cleaned.