Focus MK1 1.6 Zetec Rough idle cutting out - last ditch effort!

[hifromrich]

Hi all. 

Our Focus MK1 has started running rough on idle, RPM's seeking up and down and cutting out. Basically undriveable.

Another issue we have is that it refuses to communicate with any OBDII reader, both mine and a more professional reader at the garage, there's power to the port but does not read. I have got a DTC 9318 from the dashboard test.

We've tried changing the coil pack as this was only recently replaced with one from a scrap yard after a similar problem last year, but this had no effect this time. Two garages i've taken it too haven't made any progress in diagnosing the fault.

I've took a few quick videos to try and show what's happening.

If anyone has any suggestions i'd be grateful as the scrap yard is looming :(

https://youtu.be/262Pu8QNznU

[MrRedman]

I had uneven idle on a mk1 1.6 petrol I took the idle control valve off and cleaned it out with carb cleaner 

it's located at the front 2 bolts hold it on and it has a wire connector was fine afterwards Google the part so you can identify it if your not sure 

worth a go 👍

[artscot79]

rough idle can be ecu diodes are gone yes they can create a rough idle which might explain why its not communicating

[Tdci-Peter]

12 hours ago, hifromrich said:

Focus MK1 has started running rough on idle, RPM's seeking up and down and cutting out.

Another issue we have is that it refuses to communicate with any OBDII

What year is the car? 2001 was the date OBD compliance became mandatory for petrol cars in the EU. (Though that is model or production date, registration date may be a bit later.)

If it is not OBD2, then a ELM327 and Forscan may well still be able to communicate. I can give details if wanted.

Bad idle is most likely to be the idle control valve sticking, if it has one, or the throttle body misbehaving if it has no separate idle valve. Most Mk1s seem to have the idle valve.

These valves get oil in them from the crankcase breather, which dries to a sticky residue.

(Forscan would also be useful for the 06 Focus in your profile header.)

 

[artscot79]

mk1 has a list to work through without live data start with pcv valve if its gunked up or the springs weak you'll get idle issues then there's the pcv hose to the throttle body this can collapse under acceleration starving the engine then the idle control valve you changed the coil pack but you should change coil leads and plugs as an issue with one can knacker a new coil plugs should be gapped at 1.0mm with dielectric grease on both ends of the leads failing all that iffy o2 sensor dirty air filter or diodes or faulty throttle body

[hifromrich]

It's a 2002 so should be OBD2? There's power to the port as it will power up code readers and i've had some live data from the car showing, but doesn't now want to communicate at all. AA have also tried and failed.

It starts first time but will only hold idle for 5 seconds before the revs drop and it stalls, there's a strong smell of petrol too.

I think i'll look at the Idle control valve since it seems to be a common problem, then try and look at the other suggestions.

Thanks to everyone for their input so far, i'll keep you posted.

[Tdci-Peter]

3 hours ago, hifromrich said:

t's a 2002 so should be OBD2? There's power to the port as it will power up code readers and i've had some live data from the car showing, but doesn't now want to communicate at all.

What system showed the live data? Are you still using that same system? The OBD2 exact date could be a bit variable due to delays from production to registration.

If the interface was working, then it could be a damaged connector or wiring fault. I am not sure whether Mk1 Focus uses the CAN bus system. If it does, then there should be 60 ohms reading between pins 6 & 14 in the diagnostic connector. This is the main CAN bus used for the diagnostics, on CAN bus systems. (Test needs to be at least 30sec after ignition off.)

Looking around, it seems Mk1 Focus mostly used OBD1, and probably not CAN bus. (CAN bus is one of several approved standards for the OBD data link). I have load of data on Mk2 Focus, but very little on Mk1, I am afraid!

 

 

[hifromrich]

Hi all, we're taking it to another garage next week but thought i'd have a look at it today.

I plugged in my reader and I can view the live data etc from the car, but reading the DTC codes resets the reader.

I tried reading the codes about 10 times without luck, however on one attempt it a came up with P100 (Mass Air or Volume Flow Circuit), P0761 (Shift Solenoid C Performance or Stuck off) and C2126 (Undefined code). I haven't been able to get these codes again though.

Just clutching at straws looking for any loose connectors or damaged hoses, I tried removing the connector circled in the picture and cleaned it up a bit again and it has changed the situation slightly.

It will now idle on it's own without stalling but the slightest touch of throttle will cut out the engine. If you maintain the throttle about 25% or above it will run but the RPM seeks up/down.

Can anyone ID that circled part? Perhaps airflow related?

 

[Tdci-Peter]

9 hours ago, hifromrich said:

It will now idle on it's own without stalling but the slightest touch of throttle will cut out the engine. If you maintain the throttle about 25% or above it will run but the RPM seeks up/down.

Can anyone ID that circled part?

If idle is ok, then the bad rpm may well be the throttle body, or the throttle position sensor..

I am not familiar with this engine, but the concertina hose is from the air filter?

And the unit you have circled is between this and the engine intake manifold?

In that case, it is the throttle body, and the connector is the position feedback sensor from it.

If that is the problem, new sensors are under £20 on eBay.

 

 

[hifromrich]

Turned out to be a faulty MAP and temp sensor. Runs perfectly now!