S1 Rebuild(s)

[Dave Adams]

some pics of the rebuild process,

the top trailing arm bracket is broke......

the diff is sloping back a little (looking up) so that will need sorting.......

As you can see there isn't a lot of bracing in an S1 chassis, that will be sorted.

[Dave Adams]

the code reader did say that my O2 sensors are not working......neither of them. thing is it does have one sensor. it says the preheat is not working.

could that be the issue? would an inop O2 sensor cause a missfire?

[Dave Adams]

a little research says MAF sensor.........

i have a spare so it will get tried. wish me luck.

also i got the Jan 18 thing today.....but i could see that my posts had updated.....so i clicked on my forum posts and then back to "main" and the home page updated as it should.

[Adrian Southgate]

What year was the donor Dave and i'll look up the parts on Autocat.

Usually there is a precat and postcat sensor.

[Dave Adams]

pre cat only...... as the cat is in the bin.....

its a 51 plate 1.8 Focus donor.

could use a price for a spare in any case.....just in case, couldn't hurt to get a spare.

[Adrian Southgate]

There are pre and post cat sensors listed. Assuming the ECU is clever enough to work out your fuel to air ratio it follows that it must also be clever enough to work out that one of the lambda sensors isn't connected. If you have dispensed with other sensors surely they too show as faulty?

Pre cat lambda sensor is £30.18 + post

CAMBIARE Lambda Sensor (FR)

Product No: VE381000

Ford Focus 1.8 Dual Fuel MK 1 (1998-2005) - Estate - Part fitment dates 10/00-04/01

Ford Focus 1.8 Dual Fuel MK 1 (1998-2005) - Hatchback - Part fitment dates 10/00-12/02

Ford Focus 1.8 MK 1 (1998-2005) - Saloon - Part fitment dates 10/00-03/05

Ford Focus 1.8 MK 1 (1998-2005) - Estate - Part fitment dates 10/98-04/05

Ford Focus 1.8 MK 1 (1998-2005) - Hatchback - Part fitment dates 10/98-11/04

1796cc, 4 cyl, DOHC cam, 16v

Engine Code - 
EYDC, EYDG, EYDB, EYDD, EYDE, EYDF, EYDI, EYDJ, EYDL

Before Catalyst

Connector Type Green

Note 4 wire

Len: 400mm, Diam: 18mm, Thread: 1.5

[Dave Adams]

green connector. thats the one.

the ecu does list missing sensors as faulty, the second O2 sensor and the fuel evap purge solenoid are both not fitted. however it says that the pre cat O2 sensor pre heat is inop. i will be checking the cat fuse and the relay......the fuse needs to be quite big as it has quite a current draw.

interesting point the thread is the same as the Pinto spark plug.....

after i have checked the fuses and the voltages for the sensor i will get on to you for a replacement.

[Dave Adams]

tried to phone you during this last week adrian......no joy phone straight to answer machine.

anyway.... more checks on my car. MAF sensor removed and cleaned and then replaced for spare....fault still there so it looks like it may be low fuel pressure. unfortunately i don't have a suitable fuel pressure gauge (or at least one with suitable adaptors to use on a fuel system capable of several bar pressure.)

i do have a spare fuel pump (boy am i glad i designed my fuel tank to take standard Ford fuel pumps) so i just need to remove my boot floor access panel and then remove the fuel pump and swap it. that might solve the problem but i am still inclined to get a test gauge for future use.

i think i may also need a new lambda sensor, still checking it. it may just be a feature of the car that the sensor is only active after the car gets a little temperature into the engine.

i have been testing the car under WOT to check for the "stuttering" it has when booted......boy does it go well when pushed. (and the fault clears....)

[James Doulton]

I have a feeling that the lambda sensor is only used when cruising and even then only when the cold start fuel enrichment has finished. I think that if it was used at other times then it would be fighting with the other 'modes'. This is particularly true if it is a narrow band sensor, as I think most factory systems are. So it not working properly should not affect wide open throttle driving (unless it puts you into 'limp home mode').

If it is a transient effect when opening the throttle, then it could be that the injector positions are different to the Ford manifold, which would change the wall effect and alter the enrichment profile. But I have a feeling that they were fitted into the head, not the manifold, so that should be the same.

Is there a throttle position sensor in the system or is it just MAF?

[Big Vern]

You'd be surprised James, the Lambda sensor is used most of the time. The cold start, High load fuel enrichment and cat protection model are the only places its not used (open loop fuelling) unless there is a fault. IIRC the hego kicks in above 60degrees C coolant temp on 60 pin and 140degrees f cylinder head temp on 104 pin (Zetec and DOHC - not sure about others) the warm up allows the sensor heater to heat the lambda sensor up. High load fuel enrichment starts at 2000rpm at eecloads typically above 0.7 and riches the mixture from stoich to 13:1 afr. Cat protection model for 60&104 pin is test bed and vehicle modelled and typically kicks in about 5000rpm and richens the fuelling up to 10:1 afr to keep the catalyst within its temperature limits, this rich mixture can also have a regenerating effect on the catalyst by purging the substrate of retained oxygen (oxygen storage). Later systems use an EGT and have an active cat protection model. The only other situation where the hego sensor is not used is in LOS mode.

[James Doulton]

Interesting detail there BV.

That is sort of what I was saying - not used during warm-up and not used at high load, which seemed to be where Dave had issues. In the case of my cars, that is the only way I drive them - either warming up or WOT, or both!

I have never heard of CAT protection mode. Does it enter that mode when driving?

[James Doulton]

If the car goes well at the top end, when the fuel demand is much higher, then I doubt that it is the fuel pump or pressure regulator. The need for an extra squirt as the throttle is snapped open at 2000 rpm is unlikely to require a greater fuel supply than full throttle at 6000 rpm.

[Dave Adams]

I am going to get a fuel pressure test gauge today....I also have a Bluetooth OBD reader and Torque on my phone (along with 3 other similar apps) .

These should give me all the fuel trims to get to the route of the issues.