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S max engine change 1.8 tdci WONT START! HELP


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Evening all, I am new on here and hope help out others with my vast experience in lots of ford based problems! But, for the time being I'm looking for some one in the know to help me along with my current dilemma!

I have fitted a replacement engine to my 1.8 tdci S max after the wet timing belt decided its services were no longer required. 

Right generally I'm good with most things but this has got me a little aggravated!

I have fitted a replacement engine which is a good low milage unit which can be traced back to a low milage cat B breaker. 

It was a bare engine timed up with hp pump on so its been re-fitted with everything from my failed engine except the pump.

The pump is identical to the one on my failed engine its a siemens VDO same part numbers etc.

The problem is it will NOT start, reason being is theres no fuel coming out of the pump to the spider or 'rail'. I've got fuel to the pump and when cranking its returning fuel to the tank so no air problems etc etc. 

Question is, do these pumps need programming to the ecu like most common rail injectors do? 

I read on a transit connect forum (same engine but might not have been same fuel system) that the pump needed to be "cleared of data" and after that leaving the ignition on would allow the car to do a 30 minute learn sequence of the new pump BUT this pump in mine just has 2 small plugs what I believe to be the stop solenoid and pressure regulating valve? 

I've put all the injectors back in the same order.

all the wiring is back in the right place 

new Bosch battery

starters good

cleared all previous fault codes

I would really appreciate any feedback from anyone who has any experience of similar situations with the seimens pumps on these engines, they are common to s max, mondeo mk4 and galaxy later focus etc.

Thanks in advance. Tim.

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2 hours ago, Tim1985 said:

this pump in mine just has 2 small plugs what I believe to be the stop solenoid and pressure regulating valve? 


The two valves on the pump are a flow regulating valve (IMV), and a pressure regulating valve (PRV).

The IMV controls the amount of fuel coming from the 1st stage of the pump that is allowed to reach the 2nd stage. The 1st stage is a simple gear or vane pump that generates a few bar. The 2nd (HP) stage is a cam driven piston pump generating up to 1500Bar. When the IMV is in high flow mode, the HP pistons are pushed back fully. When the IMV is in low flow mode, the pistons can not go far back. So the HP pump is variable displacement, producing, ideally, only the flow that the injectors need. The unused fuel from the 1st stage returns to the tank.

I think the IMV stage may be a little slow to react to rapid changes, and the pressure regulating valve, on the outlet of the HP stage, provides finer and faster control, especially limiting surges. But most of the control is done by the IMV to reduce load on the engine (better mpg), and to avoid heating the fuel up too much.

It sounds like you have a problem with one of these valves, or the wiring to them.

Forscan can monitor the signals to the IMV, and I think to the PRV. I happened to notice this the other day, after doing a run using it to monitor fuel rail pressure. Forscan can monitor pressures etc while cranking, I have heard of someone doing this.

I have seen a picture of the Denso IMV system, but am not 100% sure if this is the same as the Siemens one. On this one the IMV has to be energised to raise the rail pressure. That seems likely, as it will fail to the safer, low pressure state. (I have just looked at the Ford Workshop Manuals site, and it says the IMV is closed when de-energised, but it does not say if this results in high flow or low flow, I would guess low flow.)

As far as I know there is no specific programming needed for these pumps, though there may be some learning or adaptation that happens in use.



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Thanks very much for your response & it is now sorted, I used the imv from the pump on the original engine and within a few seconds it fired straight up - result!! I thought it was going to be days of diagnostics and heartache but thankfully I had spare parts I knew worked and it was just a matter of trial and error! 

Thanks again for your help, Tim. 

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