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Discussion Starter · #1 ·
The last couple of I have had my mondeo mk3 2.2tdci cut while under hard acceleration. Majority of the time it will flash the glowplug light and give p0251 code.

Fuel rail pressure on crank without imv and injector connected is sitting at 155bar. The car idles and drives fine as long as I don't do any hard acceleration, but it will only when using gear 4,5 and 6.

I checked all fuel lines and recently replaced the leak off pipes and connectors. Fuel filter was done in December.

I'm hoping it's an easy and cheap fix.
 

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Leakoff test on the injectors, you can get a kit for £20 or so or just use some flexible tubing
and 4 small bottles.
 

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Little Megger
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155bar with IMV and injectors disconnected..? 🤔 .. should have had 1000bar minimum if pump good. BUT you could be leeching pressure due to a leaky injector, so as Purple said, cheap leak-off test 1st.
 

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Megger
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I know I will be accused of going OTT with a possible problem, but there are a number of Mk3 TDCI cars that I believe had a high pressure pump problem. Mine was certainly one of them around 120k.

Certainly a leak off will provide injector information and is a good start. But I would also suggest, remove the fuel filter and empty the contents into a yoghurt pot or something similar. Depending on the mileage on the filter, may be an idea to renew it. Check the contents of the yoghurt pot; is there any black residue and if so, is it magnetic?

If so, (or hopefully not) post back and I can provide further information.

Good luck and toodle pip
 

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Discussion Starter · #5 ·
Thanks for all the info, new filter has only around 5000 miles roughly. I will try the leak off test tomorrow, what are measurements for a good injector? Then I'll check the fuel filter if the leak off is good. Im hoping it's not the pump. I'll keep everyone updated
 

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Megger
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This was the result of my leak-off but I don't recall if this was before or after changing the pump and injectors. Given the date of the photo (2013) I think it was before, and before I found that the HP pump was the culprit.

Liquid Bottle Drinking water Drinkware Water bottle
 

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I Love Diesel
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I Love Diesel
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I would do what Rekusu suggested and check for signs of high pressure fuel pump failure. A set of reconditioned injectors isn't going to be cheap, but it would be a complete waste of money if the hp fuel pump has gone. If it has, you are looking at fuel system flush, new hp fuel pump and reconditioned injectors at least. Expensive parts and expensive labour, unless you DIY.
 

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Discussion Starter · #11 ·
I would do what Rekusu suggested and check for signs of high pressure fuel pump failure. A set of reconditioned injectors isn't going to be cheap, but it would be a complete waste of money if the hp fuel pump has gone. If it has, you are looking at fuel system flush, new hp fuel pump and reconditioned injectors at least. Expensive parts and expensive labour, unless you DIY.
What would be the signs? Reading off the obd on live data pressure is going up as it should with the revs.
 

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I Love Diesel
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What would be the signs? Reading off the obd on live data pressure is going up as it should with the revs.
It's not that, it's the bearings in the pump breaking down (case hardening?) and metal swarf travelling through the fuel system and into the injectors. It will collect in the fuel filter and you can find it with the help of a magnet.
 

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Megger
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Been there, done that!!!! Fords told me the problem, so replaced a couple of injectors. X weeks late, limp mode returned so did my own leak-off. Seems that the replaced injectors where now f-ued.

Started to investigate and found the likely reason, HP pump delivering case hardened swarf through the system. New injectors will get screwed up pretty quickly. Ford quoted around £3500 to replace everything (injectors, manifold, pump, fuel line and tank.) Couple of others quoted £2500 - £3000.

Further investigation and I became an 'expert' so decided to replace the HP pump myself. Don't recall the recon cost but pump and injectors less than £1000, and that included buying the special tools. Manifold, fuel lines and tank, taken apart and cleaned.

Filtered the drained diesel and replace, cranked the engine and it started within five seconds and has not skipped a beat since.

If is possible to do it on the drive, not so difficult and if you plan to go that route, I have some extensive pdf notes on removing the pump, dropping and cleaning the tank, cleaning the fuel lines, etc. Can post here or send directly to you.
 

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Discussion Starter · #14 ·
Been there, done that!!!! Fords told me the problem, so replaced a couple of injectors. X weeks late, limp mode returned so did my own leak-off. Seems that the replaced injectors where now f-ued.

Started to investigate and found the likely reason, HP pump delivering case hardened swarf through the system. New injectors will get screwed up pretty quickly. Ford quoted around £3500 to replace everything (injectors, manifold, pump, fuel line and tank.) Couple of others quoted £2500 - £3000.

Further investigation and I became an 'expert' so decided to replace the HP pump myself. Don't recall the recon cost but pump and injectors less than £1000, and that included buying the special tools. Manifold, fuel lines and tank, taken apart and cleaned.

Filtered the drained diesel and replace, cranked the engine and it started within five seconds and has not skipped a beat since.

If is possible to do it on the drive, not so difficult and if you plan to go that route, I have some extensive pdf notes on removing the pump, dropping and cleaning the tank, cleaning the fuel lines, etc. Can post here or send directly to you.
Sounds like best plan is replace hp pump and injector and clean everything. Trying to keep cheapish. If you send the pdfs over that would greatly appreciated.
 

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Megger
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I have attached the three files I created, Dropping the tank, Cleaning the fuel lines and Replacing the HP pump.

I am no more of a mechanic than the average person on the forum; have a reasonable set of tools but nothing special. The pump can be done with the car on the ground but if I recall correctly, I did get it onto a few bricks so that I did not have to lean over so much. I think I lifted the drivers front a bit so that I could rotate the engine timing using the front wheel.

For the tank, definitely need to be raised. Axle stands on both sides and access was improved by removing the wheels, but that is not really necessary.

Any questions, please fire away. I bought the re-conned pump and when I returned my 'worn' one, received a bit of a reimbursement. This way, I did not have to wait for the replacement to arrive and could get on with the job.
 

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Little Megger
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Definitely worth either getting yours refurbed or a new(refurbished) one from PF Jones or Bob Beck. You'll need a decent coder to recode it as well. They aren't expensive but get a dependable one from Tunnelrat electronics. We know they work properly with Ford cars
 

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Discussion Starter · #18 ·
Replaced injector 3 which is the one that was giving really weird readings. Car feels great under harsh throttle. Starts with in the second of the turn of the key. So my idea is to replace the other 3 to get to run properly.
 
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