Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When I 
switch the ignition on (but not crank the engine) the fuel pump doesn't come 
on briefly like it used to. I can crank the engine ok but it just won't run.

I've done some diagnostics and have determined that the fuel pump, the 
inertia switch, the fuses, and the power hold and fuel pump relays are all 
in good order.

The problem appears to be the ground switch coming from the ECU pin 22 that 
pulls the fuel pump relay low. Measuring between battery negative and this 
pin I get 12V when ignition is on, and while cranking. I would expect it to 
be 0v for a second or two when ignition is switched on, and also while 
cranking.

So it seems my ECU may be faulty. I have checked its pins 1 and 5 for 
battery and ignition and they are ok.

I really don't want it to be the ECU. I have heard that the Crank Position 
Sensor (CPS) could stop the ECU dead in its tracks if its not working. But 
surely this would only be the case while cranking? Can it stop the ECU from 
charging the fuel pump in the Key on, Engine off scenario too?

I will check the CPS sensor out tomorrow. Does anyone know of anything else 
that would stop the ECU from switching on the fuel pump?

"Frank McWurter"  wrote in message 
news:DydCe.2181$jo3.1879@newsfe5-win.ntli.net...

> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When 
> I switch the ignition on (but not crank the engine) the fuel pump doesn't 
> come on briefly like it used to. I can crank the engine ok but it just 
> won't run.
>
> I've done some diagnostics and have determined that the fuel pump, the 
> inertia switch, the fuses, and the power hold and fuel pump relays are all 
> in good order.
>
> The problem appears to be the ground switch coming from the ECU pin 22 
> that pulls the fuel pump relay low. Measuring between battery negative and 
> this pin I get 12V when ignition is on, and while cranking. I would expect 
> it to be 0v for a second or two when ignition is switched on, and also 
> while cranking.
>
> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for 
> battery and ignition and they are ok.
>
> I really don't want it to be the ECU. I have heard that the Crank Position 
> Sensor (CPS) could stop the ECU dead in its tracks if its not working. But 
> surely this would only be the case while cranking? Can it stop the ECU 
> from charging the fuel pump in the Key on, Engine off scenario too?
>
> I will check the CPS sensor out tomorrow. Does anyone know of anything 
> else that would stop the ECU from switching on the fuel pump?
>


power the pump separately and see if it works

"Frank McWurter"  wrote in message
news:DydCe.2181$jo3.1879@newsfe5-win.ntli.net...

> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When
I
> switch the ignition on (but not crank the engine) the fuel pump doesn't
come
> on briefly like it used to. I can crank the engine ok but it just won't
run.
>
> I've done some diagnostics and have determined that the fuel pump, the
> inertia switch, the fuses, and the power hold and fuel pump relays are all
> in good order.
>
> The problem appears to be the ground switch coming from the ECU pin 22
that
> pulls the fuel pump relay low. Measuring between battery negative and this
> pin I get 12V when ignition is on, and while cranking. I would expect it
to
> be 0v for a second or two when ignition is switched on, and also while
> cranking.
>
> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for
> battery and ignition and they are ok.
>
> I really don't want it to be the ECU. I have heard that the Crank Position
> Sensor (CPS) could stop the ECU dead in its tracks if its not working. But
> surely this would only be the case while cranking? Can it stop the ECU
from
> charging the fuel pump in the Key on, Engine off scenario too?
>
> I will check the CPS sensor out tomorrow. Does anyone know of anything
else
> that would stop the ECU from switching on the fuel pump?


The CAS circuit must be good for the ECU to prime and run the pump. Open or
short and it wont.

Ground the pump relay to make the pump run and try cranking the engine is
also a double check for a faulty CAS.

Tim..

Wow, 3 great replies all in the space of 1 hour on a Saturday evening!

I must come here more often!

I have more reason to suspect the CPS as this is in the vicinity of the 
clutch lever - the cars clutch cable had snapped after only 3 months use 
since the last one snapped. It turned out the original cable had sawn 
through the retaining bracket at the firewall - part of the clutch pedal 
abutment bracket.

It was a right pig of a job to fix, seats out the car and all. In the end I 
had to convert over to a manual clutch adjustment mechanism, involving the 
new bracket, pawl, adjuster screw, and a new clutch pedal!! All because Ford 
no longer have the old abutment bracket with the pedal stop for the auto 
adjuster mechanism.

I believe the problem was my old dad who insisted on connecting one end of 
the cable to the pedal quadrant first, and then using a crowbar to jenny the 
clutch lever to the cable. I know he slipped a few times, my guess is he 
dropped the crowbar on the CPS!

Well, I'll find out tomorrow if its damaged or not, and keep you posted. 
What kind of resistance should I read across the CPS?

I didn't try powering it, but did get a resistance of just over 10 ohms out 
of circuit, which would indicate the pumps coil is not open. However, no 
matter if the pump is working or not - I should still see the ground signal 
from the ECU at the relay coil.

"mrcheerful ."  wrote in message 
news:kXdCe.71291$G8.29414@text.news.blueyonder.co.uk...

>
> "Frank McWurter"  wrote in message 
> news:DydCe.2181$jo3.1879@newsfe5-win.ntli.net...
>> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When 
>> I switch the ignition on (but not crank the engine) the fuel pump doesn't 
>> come on briefly like it used to. I can crank the engine ok but it just 
>> won't run.
>>
>> I've done some diagnostics and have determined that the fuel pump, the 
>> inertia switch, the fuses, and the power hold and fuel pump relays are 
>> all in good order.
>>
>> The problem appears to be the ground switch coming from the ECU pin 22 
>> that pulls the fuel pump relay low. Measuring between battery negative 
>> and this pin I get 12V when ignition is on, and while cranking. I would 
>> expect it to be 0v for a second or two when ignition is switched on, and 
>> also while cranking.
>>
>> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for 
>> battery and ignition and they are ok.
>>
>> I really don't want it to be the ECU. I have heard that the Crank 
>> Position Sensor (CPS) could stop the ECU dead in its tracks if its not 
>> working. But surely this would only be the case while cranking? Can it 
>> stop the ECU from charging the fuel pump in the Key on, Engine off 
>> scenario too?
>>
>> I will check the CPS sensor out tomorrow. Does anyone know of anything 
>> else that would stop the ECU from switching on the fuel pump?
>>
>
> power the pump separately and see if it works
> 

"Frank McWurter"  wrote in message 
news:BNeCe.647$yH4.158@newsfe2-win.ntli.net...

> Wow, 3 great replies all in the space of 1 hour on a Saturday evening!
>
> I must come here more often!
>
> I have more reason to suspect the CPS as this is in the vicinity of the 
> clutch lever - the cars clutch cable had snapped after only 3 months use 
> since the last one snapped. It turned out the original cable had sawn 
> through the retaining bracket at the firewall - part of the clutch pedal 
> abutment bracket.
>
> It was a right pig of a job to fix, seats out the car and all. In the end 
> I had to convert over to a manual clutch adjustment mechanism, involving 
> the new bracket, pawl, adjuster screw, and a new clutch pedal!! All 
> because Ford no longer have the old abutment bracket with the pedal stop 
> for the auto adjuster mechanism.
>
> I believe the problem was my old dad who insisted on connecting one end of 
> the cable to the pedal quadrant first, and then using a crowbar to jenny 
> the clutch lever to the cable. I know he slipped a few times, my guess is 
> he dropped the crowbar on the CPS!
>
> Well, I'll find out tomorrow if its damaged or not, and keep you posted. 
> What kind of resistance should I read across the CPS?
>


in proper condition the cable can be pulled back with fingers or pliers to 
connect it.  probably it was looped the wrong side of the bracket.

cps 200 - 450 ohms

mrcheerful

"Tim.."  wrote in message 
news:dbbqlj$pd8$1@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...

>
> "Frank McWurter"  wrote in message
> news:DydCe.2181$jo3.1879@newsfe5-win.ntli.net...
>> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When
> I
>> switch the ignition on (but not crank the engine) the fuel pump doesn't
> come
>> on briefly like it used to. I can crank the engine ok but it just won't
> run.
>>
>> I've done some diagnostics and have determined that the fuel pump, the
>> inertia switch, the fuses, and the power hold and fuel pump relays are 
>> all
>> in good order.
>>
>> The problem appears to be the ground switch coming from the ECU pin 22
> that
>> pulls the fuel pump relay low. Measuring between battery negative and 
>> this
>> pin I get 12V when ignition is on, and while cranking. I would expect it
> to
>> be 0v for a second or two when ignition is switched on, and also while
>> cranking.
>>
>> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for
>> battery and ignition and they are ok.
>>
>> I really don't want it to be the ECU. I have heard that the Crank 
>> Position
>> Sensor (CPS) could stop the ECU dead in its tracks if its not working. 
>> But
>> surely this would only be the case while cranking? Can it stop the ECU
> from
>> charging the fuel pump in the Key on, Engine off scenario too?
>>
>> I will check the CPS sensor out tomorrow. Does anyone know of anything
> else
>> that would stop the ECU from switching on the fuel pump?
>
> The CAS circuit must be good for the ECU to prime and run the pump. Open 
> or
> short and it wont.
>
> Ground the pump relay to make the pump run and try cranking the engine is
> also a double check for a faulty CAS.
>
> Tim..
>
>


Ok, I measured the resistance of the CPS / CAS, and also verified its wiring 
was ok, by taking the reading at pins 5 and 6 of the EDIS connector 
(unplugged of course) and got a reading of 260 ohms which is within range.

I then tried grounding the fuel pump relay and sure enough the pump worked. 
Cranking the engine still wouldn't start the car, but at least I could smell 
petrol.

Could the CPS still be buggered even though its resistance seems ok? I'll go 
looking for one in a scrapyard I think...

Any other ideas?

"Frank McWurter"  wrote in message
news:oGpCe.313$Cu3.11@newsfe4-win.ntli.net...

>
> "Tim.."  wrote in message
> news:dbbqlj$pd8$1@nwrdmz02.dmz.ncs.ea.ibs-infra.bt.com...
> >
> > "Frank McWurter"  wrote in message
> > news:DydCe.2181$jo3.1879@newsfe5-win.ntli.net...
> >> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start.
When
> > I
> >> switch the ignition on (but not crank the engine) the fuel pump doesn't
> > come
> >> on briefly like it used to. I can crank the engine ok but it just won't
> > run.
> >>
> >> I've done some diagnostics and have determined that the fuel pump, the
> >> inertia switch, the fuses, and the power hold and fuel pump relays are
> >> all
> >> in good order.
> >>
> >> The problem appears to be the ground switch coming from the ECU pin 22
> > that
> >> pulls the fuel pump relay low. Measuring between battery negative and
> >> this
> >> pin I get 12V when ignition is on, and while cranking. I would expect
it
> > to
> >> be 0v for a second or two when ignition is switched on, and also while
> >> cranking.
> >>
> >> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for
> >> battery and ignition and they are ok.
> >>
> >> I really don't want it to be the ECU. I have heard that the Crank
> >> Position
> >> Sensor (CPS) could stop the ECU dead in its tracks if its not working.
> >> But
> >> surely this would only be the case while cranking? Can it stop the ECU
> > from
> >> charging the fuel pump in the Key on, Engine off scenario too?
> >>
> >> I will check the CPS sensor out tomorrow. Does anyone know of anything
> > else
> >> that would stop the ECU from switching on the fuel pump?
> >
> > The CAS circuit must be good for the ECU to prime and run the pump. Open
> > or
> > short and it wont.
> >
> > Ground the pump relay to make the pump run and try cranking the engine
is
> > also a double check for a faulty CAS.
> >
> > Tim..
> >
> >
>
> Ok, I measured the resistance of the CPS / CAS, and also verified its
wiring
> was ok, by taking the reading at pins 5 and 6 of the EDIS connector
> (unplugged of course) and got a reading of 260 ohms which is within range.
>
> I then tried grounding the fuel pump relay and sure enough the pump
worked.
> Cranking the engine still wouldn't start the car, but at least I could
smell
> petrol.
>
> Could the CPS still be buggered even though its resistance seems ok? I'll
go
> looking for one in a scrapyard I think...


I'd prefer to measure output from the CAS duiring cranking than try to
decide whether its good or bad from a resistance check.

Look for at least 3v AC during cranking.

The fact that you smell petrol from the exhaust means that the injector is
firing (it is yes?) which means the signal from the CAS is good and that the
ECU is receicving the signal, but not necessarily that the EDIS unit is
healthy.

Injection should equal spark- check the coil pack next.

Tim..

> I'd prefer to measure output from the CAS duiring cranking than try to
> decide whether its good or bad from a resistance check.
>
> Look for at least 3v AC during cranking.
>
> The fact that you smell petrol from the exhaust means that the injector is
> firing (it is yes?) which means the signal from the CAS is good and that 
> the
> ECU is receicving the signal, but not necessarily that the EDIS unit is
> healthy.
>
> Injection should equal spark- check the coil pack next.
>
> Tim..
>
>


Right - I checked its voltage during cranking and only got 1.4 - 1.6v AC - 
would this be a definite fail?

I think the petrol smell was simply because I've got the air cleaner removed 
and the bonnet open and could smell the petrol being primed to the CFI unit.

Hmm... how to check for spark without the right gear - undo a sparkplug and 
rest it on the engine looking for fireworks?

Doh!!!!

After all this I asked my Dad to make sure he had strapped all the earths to 
the negative of the battery which he insisted he had. I took a look and one 
of the three earth straps was loose!

Reconnected it and everything is working again!

Most embarrasing - still I got to learn a bit about the Ford fuel pump and 
ECU, I'm sure it will serve me well in the future.

Thanks for all your help!

"Frank McWurter"  wrote in message 
news:CvqCe.721$F_2.256@newsfe6-win.ntli.net...

>
>> I'd prefer to measure output from the CAS duiring cranking than try to
>> decide whether its good or bad from a resistance check.
>>
>> Look for at least 3v AC during cranking.
>>
>> The fact that you smell petrol from the exhaust means that the injector 
>> is
>> firing (it is yes?) which means the signal from the CAS is good and that 
>> the
>> ECU is receicving the signal, but not necessarily that the EDIS unit is
>> healthy.
>>
>> Injection should equal spark- check the coil pack next.
>>
>> Tim..
>>
>>
>
> Right - I checked its voltage during cranking and only got 1.4 - 1.6v AC - 
> would this be a definite fail?
>
> I think the petrol smell was simply because I've got the air cleaner 
> removed and the bonnet open and could smell the petrol being primed to the 
> CFI unit.
>
> Hmm... how to check for spark without the right gear - undo a sparkplug 
> and rest it on the engine looking for fireworks?
>
> 

Frank McWurter  wrote:


> Hi, can somebody help me. I have a '94 Fiesta 1.1 which won't start. When I
> switch the ignition on (but not crank the engine) the fuel pump doesn't come
> on briefly like it used to. I can crank the engine ok but it just won't run.
> 
> I've done some diagnostics and have determined that the fuel pump, the
> inertia switch, the fuses, and the power hold and fuel pump relays are all
> in good order.
> 
> The problem appears to be the ground switch coming from the ECU pin 22 that
> pulls the fuel pump relay low. Measuring between battery negative and this
> pin I get 12V when ignition is on, and while cranking. I would expect it to
> be 0v for a second or two when ignition is switched on, and also while
> cranking.
> 
> So it seems my ECU may be faulty. I have checked its pins 1 and 5 for
> battery and ignition and they are ok.
> 
> I really don't want it to be the ECU. I have heard that the Crank Position
> Sensor (CPS) could stop the ECU dead in its tracks if its not working. But
> surely this would only be the case while cranking? Can it stop the ECU from
> charging the fuel pump in the Key on, Engine off scenario too?
> 
> I will check the CPS sensor out tomorrow. Does anyone know of anything else
> that would stop the ECU from switching on the fuel pump? 


Check the Crank Position Sensor first, if the ECU doesn't get an all
clear on this circuit it won't prime the fuel pump.

-- 
Andy Hewitt **  FAF#1, (Ex-OSOS#5) - FJ1200 ABS
Honda Civic: Windows free zone (Mac G5 Dual Processor)
http://mysite.wanadoo-members.co.uk/thehewitts2/index.htm
(updated Feb 21 2005)