How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt
Matt, Mechanical Engineer
Category: Mercedes
Satisfied Customers: 23975
Experience:  BEng hons Mech engineering, in auto industry 22 years
12772297
Type Your Mercedes Question Here...
Matt is online now

I have recently fitted a recon engine to my 2012 sprinter.

This answer was rated:

hi i have recently fitted a recon engine to my 2012 sprinter. the engine runs on easy start but will not run on its own. we have 300 bar at the rail and fitted new fuel injectors also but still it will not start. I have had a mercedes tech out with there computer and there are no faults coming up.HELP needed we are stumped.
Customer: replied 9 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call.
Customer: replied 9 months ago.
Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 9 months ago.
yeah call me please

Hello and welcome to Just Answer

If the EGR valve is stuck open then this can effect starting so try disconnecting it to see if this helps or changes anything
Could also be an injector leaking fuel back through the overspill pipe, so not getting enough fuel pressure to tell ECU to fire the injectors, this is trickier to find and you’ll need the garage to do a ‘run back’ test to identify which one is the issue
you can also do a reasonable run-back test yourself by disconnecting the electrical plug on the injectors and the downstream pipe of the leak off, crank the engine over and if you see a noticable difference if the flow in the leak off then that the likely problem injector.

it’s also worth considering fitting a new fuel filter as if only slightly blocked this can lower fuel supply pressure and choke the main pump, the pump will be more sensitive to this when its cold as diesel thickens considerably with low temperatures.

I'd also check the condition of the engine wiring loom, especially on its crank and cam sensor connections as these are both critical to the ECU 'synchronising' and injecting at the right point

there should also be a ground / earth connection for the engine bay loom where its secured to the engine with a ring terminal or two and small bolts

these must be clean and tight to ensure the ECU is powered up correctly

My goal is to give you the best advice that I can and I hope that I've helped today. Please remember to rate my service by selecting from the 5 stars at the top of the screen before you leave. If you need more help, use the reply box to let me know.
If you're not pleased, also let me know because rating bad does not result in a refund, there are better options. Rating now will not close this post nor prevent further replies
Thanks Matt

Customer: replied 9 months ago.
Hi thanks for the reponse we have fitted 4 new injectors and the are spraying fuel. Egr is moving as it should all wiring has been checked and no faults found.

Ok

on the diagnostic computer do you see engine speed / rpm when cranking?

Customer: replied 9 months ago.
Dont have the computer with us now id have to ask the mercedes mechanic. We have changed the flywheel as well.

Hello

OK if you have a cheap OBD scan tool, just one of the generic ones you can get off ebay / amazon often these will have a 'read data' function so you can crank the engine whilst watching this screen to confirm if you're getting an rpm reading

as if the crank sensor is damaged or the ecu has no power then you won't be getting any injection

Customer: replied 9 months ago.
When we had the mercedes techs computer plugged in it didnt show any faults do you think it could still be faulty ??

well

if you had a faulty sensor, then this 'should' show up as a fault

however this isn't always the case hence I'd suggest checking its function with a scan tool

Customer: replied 9 months ago.
Ok we will try tomorrow and il get back to you thanks

understood

Customer: replied 9 months ago.
Hi matt we fitted a new crack shaft sensor but still the same. Do you think that the ecu could be damaged. Before the engine blew up the battery was going flat and the van was being jump started alot tge van was playing up and running rough before it blew up which made me think this could of damaged the ecu

Hello

that is entirely possible

might be worth getting in touch with either of these firms about repair and testing

http://www.the-ecu-doctor.co.uk/

http://www.bba-reman.com/uk/

Matt and other Mercedes Specialists are ready to help you