Focus 2003 zetec/lr pinging - what to check?

+Rennie+ · 09-12-2015, 12:34 PM

I have this 2003 Focus 2.0 zetec that has a pinging problem even on 98 fuel. Changed the spark plugs. Got a knock sensor but now it turns out that maybe the Australian ones don't have them...

What else should I check? Is there anything else that could cause the issue?

Note it only happens when the engine is warmed up although there seems to be slight hesitation when cold.

DZFord · 09-12-2015, 10:24 PM

Can be caused by MANY things but commonly caused by a lean condition, ie. too much air / not enough fuel. So a weak fuel pump, clogged injectors, etc., or a vacuum leak or a dirty MAF / MAP sensor.

If you have a scan tool, you can check the fuel trims, especially when accelerating / engine under load, to confirm / rule out the lean condition.
So easiest would be to check your MAF sensor (I'm assuming the LR has one, LS onwards does not).
Next you can check for any split/disconnected/worn rubber vacuum hose connections around the engine, check for a vacuum leak.
If confirmed lean, you can check fuel rail pressure by hooking up a fuel pressure test kit, but these can be expensive.
You can also get your injectors checked (spray pattern etc) and cleaned.

marg99 · 10-12-2015, 09:20 AM

vacuum leaks usually show up as the engine hunting at idle that is revs going up and down a bit not staying constant. you could expect a split rubber vacuum hose at the cars age and its always the one that is hardest to get at

DZFord · 10-12-2015, 12:48 PM

Just like my car at the moment - split PCV hose under the intake manifold. Exact symptoms as you describe. Confirmed by spraying some brake cleaner at the hose - revs dropped and engine almost stalled out.

+Rennie+ · 19-12-2015, 04:04 PM

I strengthened the pcv hose and had a look at the pcv valve. it rattles when shook but was otherwise fine. I wonder if it is the valve rattle I hear. The pinging reduced slightly after that but is still there on medium acceleration . Might get a new hose and valve perhaps? or is the valve just a rattly design?

DZFord · 19-12-2015, 07:42 PM

Different model cars. I don't think your LR has the same PCV hose problem as the LS-LV models.

The valve is meant to rattle (open and close), in fact, no rattle may mean a stuck valve.
I wouldn't get a PCV valve and hose if I was you, but try and eliminate the other possibilities first.

+Rennie+ · 19-12-2015, 08:10 PM

I will have a look for other problems though a rear pcv hose wouldn't hurt as that is the one that deteriorates and mine is a bit soft.

If there is another vacuum leak it will be small as I ran the engine with pcv unplugged and it bogged down noticeably.

small_fordz · 29-12-2015, 06:07 PM

Quote:

Originally Posted by +Rennie+

IGot a knock sensor but now it turns out that maybe the Australian ones don't have them...

The Zetec engine (1.6 and 2.0) never had a knock sensor, Australia wasn't singled out. The Sigma (Zetec SE) engine in the Mk1 Focus has a knock sensor, they came in 1.4 and 1.6 but weren't sold in Australia (the 1.6 was sold in NZ).

+Rennie+ · 31-12-2015, 02:11 PM

Ran car without MAF plugged in, revs don't hang with it off. Pinging slightly less but may just have been cooler air. Loose transmission on these cars make the rest of normal operation crappy if you don't get it perfect, clashing gears and rocking back and forth.

The pinging also seems to get a little less under full throttle so maybe it rules out things like bad injectors or crappy fuel pump/filter?

DZFord · 31-12-2015, 03:27 PM

Tried cleaning the MAF? http://www.supercheapauto.com.au/onl...spx?pid=157339

If the pinging reduces under full load it probably does lean less towards a fuel delivery issue.