Hi guys I'm new to this and new to owning a ford (usually Honda) I recently bought a '03 plate st170, 100k miles, completely standard. Engine management light was on and I was told it needed spark plugs... The car misfires sometimes up to 3k and sometimes through the entire rev range, there is a knocking noise coming from the passenger side of the engine bay when the car is idling, also misfires at idle, the car had no imrc box so I bought one, it made no difference, the cable pulls for a few seconds then releases, I've been told that is a faulty box, but the strange thing is when I reset the ecu (disconnect battery) the engine management light goes off and the car runs smooth and responsive (still has random misfire and juddering) but then when i turn the car off and back on again, the engine light is back on and the problems start again, surely if the car needed new coil pack/plugs then the problem would be a consistent thing?? I have considered it could be a problem with the fuel pump cause my tank some how fills up randomly while I'm driving, but I really have no idea what to do and I don't want to throw parts at it, so I thought I would ask the people that know, any help would be greatly appreciated, many thanks.

Joel.

 

Get a fault code reader off eBay around Ł15 and find what fault it has. When disconnecting the battery you are wiping the memory clean hence no fault until you run he car again which will then pick up the fault and log it in the memory then turn the light on again.
When the car first starts the imrc lever opens for a few seconds then returns to the closed position until the throttle reaches 5/5500 rev which is when it changes the inlet runner length.
Have you tired the Focus diagnostic test

If not keep your finger pushed on the mileometer reset stalk for a few seconds and start your engine both together , this will do a self diagnostic test , then press the stalk until you get to the dtc part if there are any faults it may have picked them up. The problem is sometimes it doesn't pick the fault up but it's worth a try.
If you get a code have a look on web by typing Focus st170 fault codes and you should be able to find out what up with it

Hope this helps.

Cheers paul

 

Welcome to the world of old Fords.

When I bought mine several months ago it had a similar misfire and it was indeed down to the spark plugs, the engine light is probably due to lambda sensors faulty and as for knocking and juddering then the clutch/flywheel would be a good guess

Lift the rear seat and check for rust on the bottom of the wheel arches, if sound and it does need a new clutch it might be worth doing, if its rotten and needs a new clutch then scrap it.

Either buy or borrow a code reader and see what error codes its showing, I would recommend buying one as its the most useful tool now on modern cars.

Good luck, you are going to need it!!

 

Thank you for the quick replies, yeah i have had the car plugged in, 02 sensors was on the list of codes but I was told that all the problems I was having was caused by the imrc box not been there, so I bought one the other day but I haven't tried anything since, list of codes are:
P0135. 02 heater circuit (bank 1 sensor 1)
P0141. 02 heater circuit (bank 1 sensor 2)
P1000. OBD || cycle not completed
C3301 Unknown fault code
P3501. Unknown fault code
C0110. Unknown fault code
P0073. Ambient air temperature sensor circuit high input
P1127. Exhaust temperature out of range
P1520. Intake manifold runner control circuit (now fixed I got imrc box)
P1650. Power steering pressure switch circuit fault


I have searched for the Unknown codes and can't find anything for them.
It's so confusing cause the car pulls like a train in the higher rev range, sometimes better then others it's as if the car has feelings.

Have I bought a money pit? It's pretty free from rust and the clutch also does feel great, the car takes off with ease when the engine light is off.
Thanks again for the replies all help is useful to me.

 

So my imrc box is actually working then? I start the car and the cable pulls tight and turns the little plastic pulley, after a few seconds it releases again. I was told that was a problem caused by faulty box, but if that's not true then that breaks down the possible causes a little bit..

 

Your p0135 , p0141, p1127 will all be related to the lambda sensor so just change.
The p1000 sounds like whoever did the diagnostic test has tried to reset the ecu to get the fault cleared and has not completed the full reset mode.
Intake sorted
P1650 sounds like another sensor or possibly a wiring fault

Cheers paul

 

Yep that's working correctly. When the car first starts it pulls fully open for a few seconds then closes. The only time the lever will move is when it's revved over 5 5.5k

Word of advise spend Ł50 on a billet alloy clip as if the plastic pulley breaks which they do very often it fucks the imrc up and new there around Ł400
Puma speed sell these

Denso plugs with msd coilpack and leads is cheaper than ford equipment , they wanted Ł100 for the leads , msd coilpack , leads are Ł130 again from pumaspeed. Plugs off eBay around Ł30 again same as ford

Cheers paul

 

Ahh right I see, thank you for that I have better understanding of how its works now, yeah I will change the sensors, plugs again, this leads and coil pack and go from there, hopefully the car will perform properly after that, and with the plastic pulley it has already snapped, the cable is now attached to a small screw.
Great help cheers mate.

 

Get the billet part as if your screw falls out or breaks it will fuck your imrc unit up again. As above buy the msd coilpack and leads as a set as they are very reliable and cheaper than ford parts , I personally wouldn't buy a copy part as unless it's made by a decent maker like Bosch etc.

Cheers paul

 

sound advice there from paul

 

You can ignore the P1000 code, that's just information.
It is set each time the fault codes are cleared or the battery is disconnected.
It will disappear when all tests are complete (without any fault).

Both heaters from the Oxygen sensors do not work properly. It is possible that you have 2 defective Oxygen sensors, but I would first check if power is supplied to the heaters.
Maybe there's a fuse blown.

 

Right then quick update, new prospark ht leads, new ngk r spark plugs, new coil pack, all bought from euro car parts, didn't buy the 02 sensors it said they wer Ł100 each I didn't know if that's right? Seems a lot.. With new ignition the car is running brilliant, was wanting to cut out on first start up but after a couple of minutes it started running smoothly, still idling very lumpy, and the engine management light is still on cause of the 02 sensors, but the car seems to be driving the best since I've had it, the engine light comes on when the imrc cable releases, at exactly the same time. I was told that the 02 sensors will have picked up the car running rich there not actually broke?

 

You can get sensors for around Ł20 each , genuine ford are Ł170 each , I used them and they've been fine so far. Mine had the same fault just replace them , if the cars running rich then it's either lambda sensors not reading right or you cat if fucked. If the code is the sensors then it's them that's why they have ob2 diagnostics to pin point the fault
Make sure you buy the sensors with the Ford connector and not a universal one as you will have to cut and crimp the cables.


Cheers Paul

 

new ngk / denso sensors for around Ł50 each and work fine too

 

I've took the car to a ford specialist called master tech, just for a proper diagnosis cause there was 3 Unknown fault codes and there is definitely something wrong with the car I did get it running good the other day, for about an hour lol, problems started again kept cutting out in low revs, at idle it would rattle like mad then cut out, if I tried to put my foot on the accelerator to prevent it cutting out it just made it bog down even more, I don't know if it's like a fuel supply issue or a head gasket maybe? Sounds like it's running 3 cylinders when idling, I did make a video of it this morning I'm not sure if I can post it on here

 

Ive taken the car to a ford specialist called master tech yesterday to get properly diagnosed, there was 3 Unknown fault codes and there was definitely something wrong, I did get it running good the other day, for about an hour.. Problems started again, cutting out as if it wasn't getting any fuel at idle, and when driving through the Rev's up to about 3.5k it would just jerk and there was just no 'bang' in the cylinder, but after 3.5k it would just surge away and pull through the rest of the gear, my thoughts are either fuel supply or timing.

 

Oh I did also find that the knocking was something to do with the clutch, the noise goes away when I press the clutch pedal in, release bearing?

 

That will be the dual mass flywheel.

 

Had the car plugged in at a ford specialis, they said all that came up was the MAF, so I unplugged it and drove the car, all the problems stopped but the car was just very low on performance, a lot of intake noise, then when I plugged MAF back in, the misfiring started again, so could this be cleaned or does it need changing?