Engine troubles in XF - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

MK XR8 · 01-30-2002, 05:40

Hi all...I have been reading the forums for a week now and decided I would join the group and ask some questions.

I have a 4-speed '86 XF Falcon S, with the 4.1 EFi engine.

I had the bottom end rebuilt around 10,000km's ago and ever since the car has been down on power and has this problem where the car will nearly stall when I slow the car and put the clutch in.

Basically the revs drop past the idle point and hit zero before bouncing back up to idle speed just in time to save itself from stalling. It doesn't do this all the time...but enough to make it quite annoying.

Another problem, which is likely linked to the first is that when slowing down sometimes, the car will surge once quite badly...then continue slowing. (This is without putting the clutch in)

Yet another problem is that when starting the car cold....it used to rev up around 1100rpm and slowly bring the revs down to normal as the engine warmed. Now it starts at 1100, then drops down to 600...then decides to go back up again. This happens a few times till the engine is warm.....then idles perfectly

And lastly fuel consumption is quite high (only getting 450-500kms out of an 80L tank)

Sorry for the long first post, but unfortunately no-one has been able to diagnose the problem as yet.

Any help greatly appreciated.

Road Warrior · 01-30-2002, 06:07

Hrrrmm....strange one. It could be one of those stupid EGR valves on the intake manifold, that can cause the motor to 'hunt' at idle, especially on the XF EFi's. Sounds like whoever did the rebuild didnt re-time it properly or check for vacuum leaks. You will probably find there is a vacuum leak somewhere causing the wierd running probs.

As for fuel consumption, hell, you're doing good if you can get 500k's to an 80L tank on one of those, the most I ever got out of mine (XF EFi 5spd) was about 400!! with moderate caning of course. My XF panno that I had used to drink even more, with a rebuilt motor, it was carbed though, with a three-in-the-tree speed.

MK XR8 · 01-30-2002, 06:16

Yeah, the guys that rebuilt it were incompetent if you ask me. I went back time after time to fix these problems. In the end I just decided that they weren't going to be able to fix it and went somewhere else for help.

Interesting...I never thought about vacuum leaks...I'll have a look tomorrow and see what I can find.