My brother owns an ef ex pursuit 5.0. Its never run real good, and seemed a little gutless for quite a while. Its been sitting with a dead battery for a few months now, but im interested in buying it off him if i can get it running.

It never used to idle, so i cleaned the maf wires, throttle body, idle speed controller, egr, and the upper inlet manifold (inside ports and all) when i removed it to get to the injectors. Ford serviced the injectors for me (22 dollars each if anyones curious). i put everything back together, hooked up some jumper leads and gave it a spin. Took a while, but eventually it fired, spluttered, then came into life Gave it a bit of a rev, then went to see if it idled, but it kept dying on me. Ive since removed the spark plugs and given them a clean, and the gaps were huge! While putting the plugs back in, i noticed i didnt have the maf connected, so i reconnected that and hooked the jumper leads back up.

Now it idles fine, and i took it for a bit of a drive. It stalled on me getting out the drive, but after that little hiccup it seemed to run ok. Pulls much harder than the i6 eb too It does however seem to have a miss down low. As though its running on seven cylinders. Sounds awesome when revved while missing. Once the revs stabilise, be it at idle, or at 3000, wherever its held, the misfire seems to go away.

What am i doing wrong? What might be causing the miss, how wide should the plug gaps be, and what are the correct ngk plugs?

Also, one final question. The car runs a k and n panel filter. on the maf wires was some gunky stuff which i assume was meant to come off? Browny yellow colour. its all gone now Are the two maf wires meant to look like fuse wire, with two little thicker metal pieces in the centre, without any resin/glue/whatever the brown stuff was?

Just been for a bit more of a cruise. It seems to surge while accelerating hard. The fuel is old, and low, which may be a problem, but the pump is almost brand new. Im running out of ideas!

Maybe an Oxy sensor.

Get a diagnostic and if the scanner picks up any error codes come up. Maybe a dyno run to see how the A/F ratio is and then see how bad the prob is.

I had a similar problem in my EF and it had a bit of surging and was leaning out. Ended up being a fuel pump and a ecu that didnt read causing it to run closed loop.


Doing both willl find the problem.

Its now back to seven cylinders. Its either a dodgy injector or a plugs not working or something. Sounds horrible! Ill have a look after lunch today

You haven't mentioned anything about the fuel filter, so I'd be changing it as a matter of course.

Plugs, leads, dizzy cap, rotor, same deal.

Certainly sounds like an ignition issue, albeit intermittent, which I'd think may be a plug fouling, lead crossfiring, etc.

I'd doubt anyone would know when the above items were replaced last, so you wouldn't be wasting money by replacing them.

Apologies if you've done all of this already.