My ef xr6 suddenly started running really rough today and then wouldn't run at all. We had a flood the night before so I assumed it was moisture that was the culprit so I let it dry for a couple of hours and tried it again. It ran perfectly for about 2 mins and then started misfiring and then died again. I went through most of the electrics with my compressor and then discovered heaps of moisture and old oil around the crank angle sensor.

I decided to take it out and check as I knew it was a quick job but I discovered something strange. The crankshaft pulley had moved back and trapped the CAS! I can't find any examples of this anywhere. There is no give in the pulley and I replaced the CAS 5 years ago. The car has been running great and still runs great for a few minutes before backfiring and stalling. Any help would be greatly appreciated!

Is the harmonic balancer same as normal on the EF? Ie two part bonded with rubber? Seems like what you described the balancer needs replacing.

Change harmonic balancer. They had a habit of slipping which stuffs timing .make sure you get the same as I think there's a couple of different ones. May have damaged sensor as well.

Thanks guys, I was thinking I would need to change it. Do you guys know if I can crack the bolt on the balancer with an auto transmission without having to lock it at the transmission? Or can I just crack the bolt in park?

prob not .... i did mine the non recommended way

Socket and breaker bar slightly above the chassis rails, disable spark and crank engine.

Thanks for the info! I will give it a go in the morning.

Ok, I got everything done except for one thing, I can't get the balancer back on! I got a new seal so it's a tight fit. Any suggestions? By the way thanks for the help so far guys.

maybe try using a rubber mallet to "lightly" tap it in? ... do watch what ya doing tho. or use a longer bolt to pull balancer on

Thanks for the help guys, It's all done! Just thought I would write how I did this for people who might visit this page.

Obvious stuff first. Removed power steering plastic cover, thermo fans and drive belt. You can take the radiator out if you want and it would make the job heaps easier but I couldn't be bothered.

You will want to remove the balancer main bolt next. I just put a breaker bar on the bolt, disconnected the coil pack and cranked the engine for a second. Same as previously described. Took no time at all.

Next thing I did was remove the balancer. You will need a pulley removal tool. Cost me $30 dollars at Autobarn. Attach the tool using three bolts in the three inner holes on the balancer and tighten until balancer pulls out and drops free. You might want to tie it off somewhere so it doesn't drop on the pipes below or just catch it as I did.

Next I decided to do the main seal because there seemed to be a fair bit of oil coming out of it. For that i used a pair of pliers and flat head screw driver. You should try to lever it out from behind and try not to damage the alloy around it. I then just put in the new seal with a soft mallet.

Now to put the balancer back on I had to get a longer bolt with the same thread as the main balancer bolt. I had one made up for $30. You then put another nut on that bolt and the bolt through the balancer. You then tighten the nut you put on the bolt and it will pull the balancer back on. When it wont go in any further, put the original bolt back on and tighten. If that made no sense the are plenty of videos on harmonic blancer tools on youtube.

Putting the rest together is easy so I will leave it at that. Just thought I would write this up because I had a fair bit of trouble with it because I have 3 ef falcon car workshop manuals that had little to no advice on how to do any of this.

Has this cured your rough running no start problems -
flood water probably caused already suspect harmonic balancer to start slipping which they were doing when the model was new.