2001 Focus 1.6 Zetec-S engine HT Leads

Genuine.

Chris.

Genuine all the time - don't buy so-called performance parts or cheap alternatives. I did that with one car to save money and it cost more as the parts didn't last as long and they were nowhere near as good. It's often cheaper to go to the main dealer! Certainly for bulbs, wipers, oil, filters and other bits.

Will do, thanks.

Morse

Thanks John, I will get the genuine part. Hopefully it will fix this damn niggling fault that my mechanic can't find!

Morse

What fault does your Focus have?

It might be worth asking in alt.autos.ford.focus

Chris

Chris,

I've already tried here and on the Focus group but the fault is a bit of a weird one.

The most obvious/irritating fault is intermittant rough/varing speed at idle. The revs go up/down/up/down rhythmically, sometimes it feels like it will cut out. Sometimes it idles quite well, but leave it for a few seconds and it usually starts acting up. An ECU reset (disconnecting the battery for half an hour) seems to help until it relearns.

There's another fault where when idling, if the revs are increased up to around 2100rpm they fail to increase with further throttle opening, causing pronounced hunting (like the idle fault), until the throttle reaches a spot (quite a bit more open) where the revs suddenly pick up as normal. The voltage output from the TPS seems to increase smoothly while the fault presents itself.

There's no fault codes in the ECU, there are no vacuum leaks (confirmed by me and mechanic) and the PCV valve and IACV have been replaced. (The old PCV valve was stuck open causing poor idle, the revs to stay high and stalling when dipping the clutch.) The air filter is clean and the car is fairly normal on the road, if a little twitchy at low speed. I have given it a dose of injector cleaner. The throttle body has been removed and checked. It is quite clean inside and it is a good seal when closed.

I've noticed the exhaust stinks of raw fuel when first started, but I thought that might be just the ECU richening the mixture for the very cold weather we've had lately! Fuel economy seems quite poor, but I have a habit of running the air con a lot.

I'm at a loss, I've seen plenty of idle faults, but the throttle issue is a bit of a strange one.

Morse

Hmmm tricky one...

Has your car had a) the modded CHT wiring loom, and b) a new CHT? If not, change them. If the leads are at all leaky and the old CHT loom in place the ECU often picks up some stray HT which causes breif shutdowns at worst and at best, strange running problems.

Next check the Clutch and Brake switches are working properly (both on the pedals) though an open or short circuit would normally be displayed in the fault codes. A fault with either will cause erratic low speed and idle speed issues. (though usually rpm hang not sway or stall)

Does yours have EGR? If so, check its not sticking open (not able to close completely at idle, when it should be) which will cause exactly your symptoms.

Also check the brake servo isnt punctured and letting in way too much air. (clamp or plug the hose to test)

Otherwise get it straight onto live data display and look at adaption levels- this should show pretty much straight away where the problem lies. (well to an experienced mechanic) I would very carefully check the output quality and switching of the o2 sensor, as on the EEC5 system - it adapts very closely to o2 sensor output (rather than fixed maps) especially at low speed, and at WOT.

Tim..

Are you the same Tim who helped me out before (last summer)? If so, thanks- it was the PCV valve which was one of your suggestions. :-)

Pass. Certainly not while it's been in the family (since around 8 months old IIRC) I tried shoving it out of the way of the HT leads but there's limited amount of wire to do so.

Will do. I'll get the dealer to check them out. Is there an easy way to spot the modded loom?

Apparently this is the non-EGR model. It's the Zetec-S silvertop with MAP sensor rather than MAF as well if that makes a difference. The MAP sensor was one of the things I suspected. It seems almost everyone else has the MAF version which makes getting web help a bit more difficult!

Will do.

Is this a dealer job or would an independent outfit have this kit/skills?

Thanks for your help, Tim.

Morse

Umm possibly, cant remember, i deal with that many cars!!

Moving and cable-tying the CHT wiring away from the HT leads is a good start. Does it help at all? If so, then definately replace the HT leads before the ECU gets goosed.

Err no.

Ah, you have a rare one. As I remember the MAP sensor is mounted directly on the inlet manifold? (well it is on the Fiesta) If so it would be worth removing it and cleaning it. Use some brake cleaner sprayed *across* the orifice, shake it around, drain, repeat. Leave it 10mins to dry after. If not, then *very* carefully inspect the hose that links the two for a split that is opening as the engine moves.

An independant is likely to be able to do it- its not rocket science! A dealer would likely look at you abit funny... In the case of a dodgy MAP, you would be able to see straight away too low an output from it just as the idle starts to get jumpy.

Tim..

I'll try that, a nice cheap test!

Correct, behind the alternator on the left side of the manifold (looking from front of car). I hope I don't have to change it because I don't know how to remove the auxiliary belt to get the alternator off! I've removed plenty of belts and alternators in the past, but I don't know about this one.

Aaah! This should be fun!

Links the two? I don't get it?

Fair enough, I'll ask around. Hopefully there'll be a Focus guru in my area who'll look at it. (Sunderland / Co Durham).

Thanks again, Tim.

Morse

If you have the MAP sensor connected to engine via a hose rather than direct mounted. (which you dont)

Tim..

I see. Yes, it's directly mounted on the 'end' of the manifold.

Morse

Hi Guys,

What solved this problem you guys discussing here because i also have same prblem. Only difference is that mine is black top Zetec-SE engine on 2003 ford Focus.

I changed the plugs but didn't cured it. I also have checked my plug cable resistance which were same for everyone. I also cleaned the MAF sensor located near the airfilter box.

Recently I add the STP fuel system cleaner. Which have Improved 5%. But sometimes it doesn't feel like it.

Sometimes car by itself become okay and very reponsive even when A/C is working. and then back to same problem. This happen with in a day. like the car have moods.

Br, Zeeshan

url:

most petrol fords have the same faults: plugs, leads, coil pack and in your case I would first look at the catalytic converter, it has probably broken up inside, this allows the broken part to fall sideways into the exit from the box which blocks it, till it moves a bit and unblocks (if you are lucky) Removing the exhaust section behind the cat. and looking inside you can usually see if the cat material is loose and movable. The material is in two halves to start with, it is usually the back bit which becomes loose. I have often removed the cat. cut a hole in the side, removed the loose bit of material and welded the hole shut for several years more use.

Both Zetec E and SE engines need to have the plugs *and* HT leads replaced with genuine Ford ones every 40,miles.

Measuring the resistance will not always show up a faulty lead, especially as your fault is intermittent.

Chris