P0207 - Fuel Injector 7 Circuit Malfunction
 

Dear Forum,

I started my car up this morning to double check that I was still getting short to battery code for the L/H rear damper and I had stupidly forgotten to reconnect my ASM and my Centre Console! So obviously I got a host of DTC's, but more importantly, among them I now have PO207, PO307 & P1316 - All pointing to number 7 cylinder injector circuits.

So I have succeeded in turning a car performing beautifully but with a CATS problem that was not affecting its performance in any way to one with a Restricted Performance light and a missing, shaking and backfiring engine!!

I am on Pinpoint test G290117p1 and I have fallen at the first hurdle (resistance between 12 & 16 ohms). I got 19.26 ohms the first time I tested, then 16.90 the second? To be honest, the reading keeps going up and down again? Anyway, I tried injector 5 for comparison and I got 16.70 ohms (again a bit up and down)?

Please, are these acceptable enough for me to go on to the next pinpoint test (G290117t2)?

Hi EsRay,

I have recently had to replace my injector that was the same cylinder as yours and was open circuit P0207. It had however started to fail and throw the restricted performance warning as well for a period of time before it completely failed. When tested for continuity it was open circuit (showed 1 on my multimeter). I also had to replace injector five last year with the same problem.

I tested a new injector before fitting and it was getting approx 14.9 and all the other older ones where reading between 14.7 and 14.8.

If you are getting ohms readings which are not steady when held for a period of time then that may indicate a failing injector. Check it five to ten times and see if the readings settle each time. If they do not settle then the injector is most likely bad and you will eventually get an open circuit situation.

I presume you are testing the injector directly at the pins with the electrical connector removed. If you try to read the ohms via backprobing through the connector you may see odd values.

It is quite straightforward to replace the injectors in these cars if you have the N/A like ours. Depressurize the fuel rail, remove fuel rail and replace injector. Remember to get some spare o-rings in case the ones on the other injectors need to be replaced whilst you are in there. A small amount of engine oil on the o-rings when reinstalling them into the head and/or the fuel rail will help them go back in very easily - otherwise you risk pinching them and then you have a fuel leak after putting it all back together again !

Thanks,

Chris

I am tempted to simply swap injector 7 for (say) injector 5 and see if the DTC moves? Please, would I have to disconnect all the injectors in both banks, plus the fuel supply line, or could I get away with just disconnecting bank 1 and lifting it a little to achieve the swap?

I had all 8 injectors professionally cleaned & serviced (new o rings etc) a few months ago and my car has been running beautifully?

Chris, thank you for your reply. I feel a little foolish now...I was testing the connector? I assume that if I have to get to the pinpoint that measures the voltage with the ignition on, that measurement would have to be at the connector?
I'll test the pins inside the injector tomorrow and get back to you!

Regards,

Ray (Mr Foolish)

Chris, thank goodness you took the time to post your reply!

I have Open Loop at injector 7 PINS and 14.7 ohms at injector 5 pins

Had you not forestalled me, I would probably have ended up pulling my wipers, cowl vent screen, cabin air filter etc, etc to get at my ECM AGAIN (I previously pulled it all out to pinpoint test the circuit to my Fuel Rail Pressure Sensor, a test which had failed at the connector (the connector in this case being the correct place to test). Mierion1, Cambo and others were electronically shouting at me that it was the aftermarket Sensor replacement I had bought, but I was stuck in the belief that if the pinpoint test pointed to a fault in the wiring, the wiring it must be?
However, I eventually listened to them and bought a second-hand Ford Focus FRP sensor and off she blazed!
Since then, I really do not have complete faith in pinpoint tests and I have no faith whatsoever in aftermarket sensors!!

So, thanks again and it appears that a new Injector is the solution.....Please, any suggestions as to where I should buy one (bearing in mind I will have to ship it to Dubai)?

Hi Esray,

Glad you found the problem and that it was what I thought. You are not foolish. It's an easy mistake to make when testing. Really glad to be of help to a fellow member.

Yes you should test for OHMS with no power running through the unit and with the connector removed. You can test from the connector but you have to connect to the other end of the wire at the other end of the loom. You cannot test for ohms with the car running as the ECU pulses current to the injector to control the flow of fuel through the injector so you will get some odd numbers when testing. Looks like you got similar readings to mine on the good injector so I think that is the right number to look for when they are working. I now use that value to check my other injectors when I have an issue.

The fuel rail on our cars are connected from bank 2 to bank 1 via a slightly flexible rubber hose at the top front of the engine just behind the throttle body. Therefore, you can just unbolt the fuel rail on bank 1 (torx head bolts I remember) and lift it up. At the back of the fuel rail on bank 1 you have a sensor that is quite tight and needs to be disconnected to get the rail a little further out of the way to get to injector 7 which is right at the back. You may also have to disconnect the vacuum hose from the fuel pressure sensor at the front of the fuel rail on bank 1 to give you some more room. You'll also have to take off the oil return pipe that crosses the fuel rail on bank 1. Remember to disconnect your battery and depressurise the whole fuel rail before work which you can do by using the schrader valve on bank 2.

The fuel rail can be a little tight so just pull the rail up and the fuel injectors should all come out with the rail on that side.

To disconnect the injector from the fuel rail just push the retaining clip back. When refitting, be very careful and double check that the retaining clip is fully engaged in the slots on the side of the injector and you should feel a 'click' when it is fully in place.

This is the fuel injector for our cars below. It is shared with the S-Type with the 4.2 engine. I got mine from SNG Barratt as they are only £48 inc VAT at the moment. Not sure about the cost of delivery though to you Probably still cheaper than buying an injector from a dealer. I think the aftermarket ones are a lot more expensive. It also comes pre-fitted with both o-rings. Just buy a spare set of o-rings just in case as my last one just came with one !
Fuel Injector - SNG Barratt

And these are the o-rings to get for the other fuel injectors on that rail as it's worth getting these for each other one and replacing whilst you are in there.

Lower Fuel Injector O-Ring - SNG Barratt
Upper Fuel Injector O-Ring - SNG Barratt

Each o-ring shown above is a slightly different size so you do need to order each of those for each injector should you wish to replace them.

Again, smear the o-rings with a small amount of engine oil once they are on the injector before refitting the injector into the fuel rail and the other end into the head.

After you have everything back together you may get misfire codes for that bank and you may also get a fuel pressure sensor fault. I had this and simply switched off, cleared the codes and restarted. This is normal as you have opened up the fuel rail and its not fully pressurised when you start the car for the first time. I had this with mine on both occasions when replacing the injectors. Make sure that there are no smells of fuel or signs of leaking. The first time I did this on injector 5 I pinched an o-ring and had a leak that I could not see but the fuel rail would depressurise after leaving the car for a while so it was straightforward to spot I had a leak. If you notice difficulty starting the car after your work then you know you have a leak in that bank somewhere.

If you get stuck or need assistance then just give me a shout. I think I have some pictures of the injector replacement somewhere if needed.

Thanks,

Chris

Thank you Chris; difficult to see how I am ever going to get a more comprehensive and cohesive answer to a question than yours!

You're welcome Ray. Good luck with it and I the delivery of the part is not too expensive.

£40 + £23 shipping from SNG Barratts in the UK. Ordered on Tuesday. Arrived here yesterday (Wednesday). Usual Customs delay and tomorrow is the Sabbath here, so nothing gets delivered. Will have it Saturday.
Main Jag dealer here (Al Tayer Motors) quoted over £200, payment in advance and delivery in two weeks or more!

See what we are up against, here!

Hi Ray,

Yes the SNG Barratt one is a bargain and has been for a while as I got the same one over a year ago for my other failed injector at a very similar cost. Your delivery arrived pretty quick but at least it's well under the cost and timescales from the dealer. Two weeks or more, whatever next !

Thanks,

Chris