Technical 100HP wont start no warning lights showing

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Technical 100HP wont start no warning lights showing

DaveMcT

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The car has hardly moved for weeks but has been started and run to full temperature every couple of weeks. Yesterday it started fine. Today there is no fuel pump noise and no attempt to start.

The immobiliser light goes out and it cranks normally, but there's no attempt to fire up.

Checked the fuses all ok

Removed and replaced all relays but not (yet) tested any

Disconnected battery for an hour no change
Pressed the intertia reset button no change.

I'm thinking fuel pump as it's not sounding when door is opened, but don't want to buy one only to find there's no change especially with Covid delivery issues. How can I test the wiring to the pump?


Any thoughts as to what else it might be? Any thought on what tests I need to do?

My windows laptop went AWOL so I don't have MES.
 
Apply battery voltage to the fuel pump fuse listen for fuel pump running
 
The handbook suggests F21 but in brackets says "Multijet version". I cant find a fuse specifically for the petrol fuel pump. I (naively perhaps) assume the 100HP is fused same as 1.1 and 1.2.
 
"I'm thinking fuel pump as it's not sounding when door is opened, but don't want to buy one only to find there's no change especially with Covid delivery issues. How can I test the wiring to the pump?"

Not sure where the door comes into it



pump comes on for approximately two second when you First turn the key. Regardless of if the doors open or closed


as its fairly quite and under the rear seats its easier to here with the door shut, radio and blower off.
 
Whatever the routine is I can't hear the pump run. There's a relay click in the under-dash fusebox but no other sounds.
 
Delivery is a bit slow, but not had any actual issues for to covid?

I assume the plug to the pump can be accessed by removing the rear seat base? If So, stick a bolt meter on and as you turn the key see if you measure 12v at the plug.

Try that and we can work from there..
 
Delivery is a bit slow, but not had any actual issues for to covid?

I assume the plug to the pump can be accessed by removing the rear seat base? If So, stick a bolt meter on and as you turn the key see if you measure 12v at the plug.

Try that and we can work from there..

It should makes sense in context

Quote - separated -

"I'm thinking fuel pump

as it's not sounding

but don't want to buy one

only to find there's no change - especially with Covid delivery issues. (meaning slow delivery)

How can I test the wiring to the pump?"

End Quote

It's odd because fuel pumps usually hiccup before they pack up. This has had no previous symptoms.
I'll report back with findings
 
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Apply battery voltage to fuse 21 engine bay fuse box, if fuel pump doesn't run then fuel pump or it's wiring is at fault.
If that is the case then remove reae seat etc and check for voltage at pump within two seconds of key on or while engine cranking on starter
 
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you can check for fuel delivery via the schrader valve in the fuel rail


normally a wack with a piece of wood is enough to get them going again.


There's a Good chance the neck of the fuel tank will have expanded and the locking ring will be very, very tight. You really don't want to remove it unless absolutely need to.
 
I would get under the car and give the fuel tank a few taps with your hand. I had a similar problem with our 1.1L Panda and that's what the RAC mechanic did and it removed the blockage. Unfortunately, it did end up having to have a new fuel pump.

As far as I remember, the fuel pump has the fuel filter built in, so you are changing that at the same time.
 
Apply battery voltage to fuse 21 engine bay fuse box, if fuel pump doesn't run then fuel pump or it's wiring is at fault.
If that is the case then remove reae seat etc and check for voltage at pump within two seconds of key on or while engine cranking on starter

I've put power into the fuse 21 nothing happens. The fuse (7.5A) is ok by the way.

According to my manual you should check fuse 16 and 17 (under the hood).

gr J

I have checked every fuse and found none are blown.

I pressed the fuel rail schraeder valve (rag covered). There was very little pressure. Putting the ignition on was still silent. At least this proves that fuel is not being pumped.

I have taken the rear seat out and have access to the fuel pump. I need to make up some wires so I can see the voltage pulse at ignition on. By the time I get there to connect the voltmeter, its gone.

I have not been able to download a wiring diagram. They all demand credit card data and all seem to use the same data collection page.
 
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I've put power into the fuse 21 nothing happens. The fuse (7.5A) is ok by the way.



I have checked every fuse and found none are blown.

I pressed the fuel rail schraeder valve (rag covered). There was very little pressure. Putting the ignition on was still silent. At least this proves that fuel is not being pumped.

I have taken the rear seat out and have access to the fuel pump. I need to make up some wires so I can see the voltage pulse at ignition on. By the time I get there to connect the voltmeter, its gone.

I have not been able to download a wiring diagram. They all demand credit card data and all seem to use the same data collection page.
If you can rig a bulb and some wires to connect to fuel pump socket you may be able to see it more easily while turning key
 
I've just rigged up the voltmeter to the fuel pump plug and checked while turning the ignition key. There is no voltage - nothing at all.


Next job to run battery power direct to the fuel pump to confirm it's ok. My guess is that it will be, but let's see.
 
Be careful there is wiring for fuel level sensor as well as fuel pump connected to top of pump/sender unit.
 
Thanks for the warnings. There are four wires to the tank level sender/pump connector block. I reasoned the thick wires would be for the pump.

First I held a voltmeter against each terminal on the back of the connector. Conveniently the bullet tips on my voltmeter prods sort of popped into place. With a helper on the ignition switch, there was no power getting to the fuel pump though I did get a lower voltage from the sender.

The pump contacts are small but I have a set of various sized female spade connectors so made up a temporary lead with two connectors. That safely put power to the fuel pump. They are fussy to fit but do connect firmly. The upshot is that with the pump running strongly, there is fuel at the fuel rail and the engine still wont start.

I thought in spite of the immobiliser light going out, maybe it is the problem so tried the spare key. No change. Engine spins over but no start.

I've managed to borrow a Windows computer so downloading .net to see if MES can find the problem. It reminds me of exactly why I don't like Windows PCs but hey if it helps sort the problem.

To anyone going to the fuel pump wiring connctor. (1) pull out the yellow security tag. (2) LIFT the tag on the lower side. Its very fiddly but easier if you have an old flat blade screwdriver where you can bend up the end to make a puller. (3) lift the tag from the under side and the connector pops out easily.
 
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