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Car won't start!


hawksa

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if its a standard westfeild loom there will be a fuel pump relay in with the wiring for the ecu. being as your getting power to the fuel pump your fuse for the fuel pump must be ok.

im not sure on your yours but on mine the fuel pump relay runs off the power relay to the ecu so without power to the ecu the fuel pump wont run. assuming yours is the same then you must have power to the ecu. in turn means that you arent getting a signal from the crank position sensor. im not sure where it is located on the zetec.

do you have the facility to connect the ecu to a laptop

 

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If I'm getting the 'prime' signal (0V then 12V then 0V) to the fuel pump but no fuel is 'primed' does this not indicate a problem with the pump?

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Are you on Weber DCOE's or Bike carbs ?

If so what type of fuel pump / regulator have you got?

If it's a standard "Facet" type - it must have a power supply and earth (the power coming presumably from the ECU / relay?)

If this is the type of setup, then as I mentioned before, why not just run a direct power supply to the pump positive input (also perhaps check the earth and if in doubt run a separate new wire to the earth connection / chassis point) - if you ran the wire(s) directly back to the battery then you are bypassing any relays / ecu's or dodgy wiring / earths.

You don't even need the ignition switched on.

If you don't get any fuel being pumped through with this test then obviously there's something wrong with the pump (or any inline filters). If you do get a good fuel supply then it's just a process of elimination in the circuitry from the ecu to relays / ignition witch / power supplies etc.  

Full details of engine / ignition / ecu / carburettor types / fuel pumps etc would help us to try and isolate where the problem may be given typical problems we may have seen in that configuration ???

Colin

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I think the ecu only switches on the pump to prime for a few seconds when you stick on the ignition .   After that it stops intil it senses a cranking action that it does  Via the cps.    So my vote is either the ecu loom relay is dead.  The fuse for the ecu either the switched or perm lives have gone,  earth gone.. or the cps is with not connected or dead.  

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yep damperman is right. one of the fuses in the two fuse boxes is a main fuse but i carnt remeber which one puts power into the ecu. i blew this on the way to iva lol and the car wouldnt start. so check your fuses. try swapping the relay. but you say you had been doing work behind the dash so possible that one of the fuses has gone.

are you able to plug the ecu in so that when you turn the ignition on you can actually see what the ecu is doing.

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12 hours ago, hawksa said:

If I'm getting the 'prime' signal (0V then 12V then 0V) to the fuel pump but no fuel is 'primed' does this not indicate a problem with the pump?

Your logic is sound. If you have 12v at the pump and its not pumping it does sound like a broken pump.

If you want to be sure just run a temporary 12v feed to the pump from a battery. You should hear it pumping

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Always a frustrating problem. You'll get there in the end. Or there is a short cut to getting it to start again...

Jen :)

Sure this has been posted before, but can't remember where, or when.

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On ‎16‎/‎12‎/‎2016 at 07:56, Trevturtle said:

Your logic is sound. If you have 12v at the pump and its not pumping it does sound like a broken pump.

If you want to be sure just run a temporary 12v feed to the pump from a battery. You should hear it pumping

Well a direct 12v feed from the battery nd no joy.  A new fuel pump for me then.....:cry:

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1 hour ago, hawksa said:

Well a direct 12v feed from the battery nd no joy.  A new fuel pump for me then.....:cry:

Just to clarify:

- direct feed, fuel pump doesn't run

- on prime you get 12v signal for 3 seconds. I assume it doesn't run?

 

If the first one, I'd check the earth om the pump to start with and / or give it a tap with a mallet. You could run a direct negative feed to the battery also.

 

Re the crank position sensor, do you get spark when cranking?

 

Few other easy tests but looks like the pump / pump wiring is the main suspect

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10 hours ago, darve said:

Just to clarify:

- direct feed, fuel pump doesn't run

- on prime you get 12v signal for 3 seconds. I assume it doesn't run?

 

If the first one, I'd check the earth om the pump to start with and / or give it a tap with a mallet. You could run a direct negative feed to the battery also.

 

Re the crank position sensor, do you get spark when cranking?

 

Few other easy tests but looks like the pump / pump wiring is the main suspect

The direct feed from the battery was both 12v and a negative feed. I'll order a new pump today.

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New fuel pump delivered and fitted. I now have a car that starts!

I just need some time over Xmas to progress my build now!

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