weeks back I got the Engine Malfunction light on my Mondeo. Due to which there was loss of power and more than usual vibration. Car took a long time to reach 25-30 miles. So I called the Breakdown guys who took me to the nearest Ford Gararge, they ran a diagonistics report and suggested to change a part think its called the Fuel Solenoid - it sits next to the engine(it cost me £400 to replace it, incl Diagonistics+Parts+Labour). The problem was however not fixed, got the light back on again the next day. Took it to another Ford Garage, they ran another diagonistics report (and paid £96) and they suggested that cylinders 1 and 4 werent getting any power and the car was only running on the remaining 2. I was also suggested that the ECU / PCM was faulty and needs to be replaced (new one costs £1,450 to replace in Total). Didnt do that as i have read a lot of online reports where changing the ECU / PCM doesnt solve the problem. Then I took it to another garage (non Ford this time) who then ran a diagonistics report and then sent the ECU / PCM to a specialist company in Nottingham to check any faults with it and reprogram it if required. They sent it back saying the ECU/ PCM was fine. The garage then swapped my ECU with another used one to check if that solved the problem - still no change. They even swapped my trottle to see if it fixes the problem - still no change (i spent another £150 here). So its now been 4 weeks, the car is not fixed and I am down £650 and without my car running. Not sure what else I can do to get it fixed. Even borrowed a friends diagonitcs tool to see if we get any error codes, we got P0206 (Injector Circuit malfuntion) and P0721 (Output Sensor Noise Interference)

Any help or suggestions most appreciated.

That's an appalling story. there is a side order of what legal/formal action you can take against what seem to have been a bunch of incompetents, in that the work that they did didn't actually work; if you paid via credit card maybe there is some recompense there?

Anyway, on to the main event.

Given that it has been suggested (how? what told them this?) that 2 and 3 are working and 1 and 4 are not, has anyone checked that the coil packs are ok?

If there is a reliable way of telling which cylinders are working, if this swaps over when the coil packs are swapped, then a coil pack is defective (or the connections are corroded). It could still be the wiring to the coil packs or the HT leads to the plugs, the 'swap' test doesn't show anything about that.

Has anyone checked that the injectors are delivering fuel in the correct quantity? With four transparent vessels, you should be able to see that all four are supplying similar amounts of fuel, and that none of them are leaking fuel when injection is not required.

Also, checking the fuel pressure would have been sensible. Did anyone do that?

(And, I suspect that I know the answer to this) When the condition of the spark plugs was inspected, what clues did they give?

Even borrowed a friends diagonitcs tool to see if we get any error codes, we got P0206 (Injector Circuit malfuntion) and P0721 (Output Sensor Noise Interference)

Had anyone else checked and cleared the codes, so that you know that these are new codes (what were the codes that had been cleared, or did no one tell you?? I can probably guess that, too, but maybe I'm I'm just being negative.)

Injector circuit malfunction sounds like:

• the injector, itself
• wiring to the injector
• the driver (but, swapping the ECU ought to have eliminated that one)
• possibly wiring to the ECU (maybe earth connection or an intermittent fuse or connection, although you'd expect a whole load of errors for that)

The Output Sensor Noise Interference sounds like the module detecting the switching transient from an inductive load, or more exactly, not detecting it reliably. That sounds like a wiring fault (intermittent, probably) or a bad injector or coil pack.

Given that pile of possibilities, I'd be doing some poking around the wiring first. In particular, I'd get the engine running and give the wiring (injectors, coil packs) a bit of gentle pulling and pushing and see if anything changes. You may want the coil reader (and friend?) connected to see if any new codes pop up.

Thanks for the detailed reply. The intake manifold control solenoid was changed (i.e. have a new one). So will ask to check if the injectors are delivering fuel correctly or not. We had also cleared the codes and started again so as to make sure we dont keep looking at the old ones. Spark plug was checked and cleaned during its last service in May 2014. I have taken a printout of your reply and will take to the garage tomorrow. The current car mechanic seems alot more experienced, and has mentioned checking the coils and swapping them to see if the problems with cylinders is due to faulty coils. He is also checking all the wiring as we speak. Hopefully we find the fault soon. Will keep you posted and thanks again for the reply

Hi ive just had exactly the same pot 1 and 4 not firing its because your cat is blocked so not getting enough vacuum to the inlet flaps unscrew your 02 sensor and remove then take for a quick drive it allows enough pressure out to let you no hope this helps

On 8/3/2020 at 8:48 PM, mk4andy said:

Hi ive just had exactly the same pot 1 and 4 not firing its because your cat is blocked so not getting enough vacuum to the inlet flaps unscrew your 02 sensor and remove then take for a quick drive it allows enough pressure out to let you no hope this helps

Hi mate I have the same problem, I did what you said but no difference, my mechanic said sometimes there is no spark on cylinder 1 and 4. Coils have been checked and spark plugs. The car has lpg and it's the same on petrol and lpg. Any ideas are welcome.