fiesta 1.25 zetec labours above 4000 rpm. Solutions?
ChrisJ
first time every time and runs fine and smoothly. However I have the
following two problems.
Problem 1.
After starting, although the engine sounds fine its absolutely gutless
and has a real job pulling away up a slight gradient (yes I AM in first
gear and the brake is off). Once its warm its OK. No problems at all.
My only thoughts are that it might be something to do with the auto
choke which is the only thing I can think of that would be so different
with a warm engine to a cold one. This has been going on for about 2
months.
Problem 2.
This started after the service and it didn't happen before the service.
We live in a hilly area and so regularly use engine revs between
4k-6k. Before the service the engine would rev freely into this range.
Now however the engine revs freely (as before) until it hits approx
4100 rpm then its like someone has put the handbrake on and the engine
only accelerates slowly to 6k. Its a real change in acceleration.
Change gear and the engine pulls strongly up to 4k again.
The garage noticed this at the last service (2 weeks ago) although we
are sure it didn't happen before. They have changed the fuel filter to
try to fix this problem. Their computer said the car was reporting a low
fule pressure but they couldn't work out where.
I'm not sure if either of these is related but any suggestions appreciated.
(inlcuding a more appropriate list/forum of necessary.
ChrisJ
AstraVanMan
> first time every time and runs fine and smoothly. However I have the
> following two problems.
>
> Problem 1.
> After starting, although the engine sounds fine its absolutely gutless and
> has a real job pulling away up a slight gradient (yes I AM in first gear
> and the brake is off). Once its warm its OK. No problems at all. My only
> thoughts are that it might be something to do with the auto choke which is
> the only thing I can think of that would be so different with a warm
> engine to a cold one. This has been going on for about 2 months.
Well it won't be an auto choke. Chokes are for cars with carburettors.
Yours has injection. That clears that one up.
> Problem 2.
> This started after the service and it didn't happen before the service. We
> live in a hilly area and so regularly use engine revs between 4k-6k.
> Before the service the engine would rev freely into this range. Now
> however the engine revs freely (as before) until it hits approx 4100 rpm
> then its like someone has put the handbrake on and the engine only
> accelerates slowly to 6k. Its a real change in acceleration. Change gear
> and the engine pulls strongly up to 4k again.
> The garage noticed this at the last service (2 weeks ago) although we are
> sure it didn't happen before. They have changed the fuel filter to try to
> fix this problem. Their computer said the car was reporting a low fule
> pressure but they couldn't work out where.
That's the problem with a lot of garages these days. So many of them are a
bunch of clueless fuckwits who'll tell you what the computer says but can't
actually find what's causing that problem. Engines aren't *that*
complicated these days. It's still the basic suck/squeeze/bang/blow
principles, just a little more complex on how much is sucked (and the rate
it gets sucked at), exactly how much it's squeezed, exactly when it goes
bang, and how easily it goes blow.
Take it to a garage with a clue.
Peter
Tim..
"ChrisJ" <ch...@youmustbejokingifyouthinkImputtingmyrealaddresshere.com>
wrote in message
news:42b6b9c9$0$41910$ed26...@ptn-nntp-reader03.plus.net...
For a start the last part is bollox. The ECU (at least on this Fiesta) is
not able to directly measure fuel pressure- it has no sensor in the fuel
rail. (it could signal a long term fuel trim value exceeded though- but this
could be caused by more things than just lack of available fuel)
You have one of three problems:
1) ECU entering limp home mode due to major sensor speed related failure- eg
cam sensor or MAF. This would be my guess. Fiesta's of this age do not have
a MIL lamp to indicate a fault.
2) Restricted fuel supply- blocked line / filter or weak pump- would only
show under high load / wide throttle openings.- is it better in a lower gear
with a smaller throttle opening revving past 4000, or the same?
3) Restricted Exhaust (but this would be apparent both hot and cold and not
suddenly at specific revs)
Does the car misfire at all, or is it just holding back ? If its missing, or
spluttering then you have an ignition problem.
Has fuel consumption increased suddenly?
Tim..
ChrisJ
Good point about the choke!
This garage suggested the many things it could be. But they said
without changing them all one by one they couldn't be sure. I was
trying to avoid the cost of changing all the working bits as sods law
says they have to change them all before they find which one it is!
Chris
ChrisJ
They just said they plugged their box into the car and it indicated low
fuel pressure. Or I misunderstood. Would a genuine ford garage be able
to diagnose more?
> You have one of three problems:
(or knowing my luck 3 of three ! ;0)
>
> 1) ECU entering limp home mode due to major sensor speed related failure- eg
> cam sensor or MAF. This would be my guess. Fiesta's of this age do not have
> a MIL lamp to indicate a fault.
This was suggested
>
> 2) Restricted fuel supply- blocked line / filter or weak pump- would only
> show under high load / wide throttle openings.- is it better in a lower gear
> with a smaller throttle opening revving past 4000, or the same?
>
In each gear 1-3 it revs to approx 4100 and then acceleration is
markedly less. It may do this in 4th as well but that would be over
70mph I think so I can't be sure ;0) as I haven't tested it, honestly.
It seems to be almost exactly the same in each gear (within 100 rpm).
The filter has already been replaced to try to alleviate this. Could
the fuel line get trapped/pinched by jacking or other work carried out
during a service? I'm assuming its metal and so would remain the shape
it was squashed to. Remember, although it misfired when cold before the
service it did rev freely above 4000 rpm and its only since the service
its had problems with high revs.
> 3) Restricted Exhaust (but this would be apparent both hot and cold and not
> suddenly at specific revs)
>
Agreed, I'm assuming it would sound different too and afaict its still
the same.
>
> Does the car misfire at all, or is it just holding back ? If its missing, or
> spluttering then you have an ignition problem.
It only misfires when "cold and being gutless" pulling away but after
2-3 minutes it runs smoothly. It runs smoothly above 4000 rpm too
sounds just the same, the only difference is the acceleration.
Having said that it started OK from "cold" today (but it is hot outside!)
>
> Has fuel consumption increased suddenly?
>
That's a difficult one as I didn't drive the car much before but I've
just been told it used to do about 220 per tank (to red) and now does
about 180. Since I've been using it more its done 200 ish but as I use
it infrequently (relatively) I don't tend to fill it up. We tend to
reset the trip when we fill up so these are quite accurate.
> Tim..
>
>
Anybody care to suggest a most likely cause or a the cheapest
sequence/method of getting this sorted?
Thanks for your replies BTW.
Chris
ChrisJ
They just said they plugged their box into the car and it indicated low
fuel pressure. Or I misunderstood. Would a genuine ford garage be able
to diagnose more?
> You have one of three problems:
(or knowing my luck 3 of three ! ;0)
>
> 1) ECU entering limp home mode due to major sensor speed related
failure- eg
> cam sensor or MAF. This would be my guess. Fiesta's of this age do
not have
> a MIL lamp to indicate a fault.
This was suggested
>
> 2) Restricted fuel supply- blocked line / filter or weak pump- would
only
> show under high load / wide throttle openings.- is it better in a
lower gear
> with a smaller throttle opening revving past 4000, or the same?
>
In each gear 1-3 it revs to approx 4100 and then acceleration is
markedly less. It may do this in 4th as well but that would be over
70mph I think so I can't be sure ;0) as I haven't tested it, honestly.
It seems to be almost exactly the same in each gear (within 100 rpm).
The filter has already been replaced to try to alleviate this. Could
the fuel line get trapped/pinched by jacking or other work carried out
during a service? I'm assuming its metal and so would remain the shape
it was squashed to. Remember, although it misfired when cold before the
service it did rev freely above 4000 rpm and its only since the service
its had problems with high revs.
> 3) Restricted Exhaust (but this would be apparent both hot and cold
and not
> suddenly at specific revs)
>
Agreed, I'm assuming it would sound different too and afaict its still
the same.
>
> Does the car misfire at all, or is it just holding back ? If its
missing, or
> spluttering then you have an ignition problem.
It only misfires when "cold and being gutless" pulling away but after
2-3 minutes it runs smoothly. It runs smoothly above 4000 rpm too
sounds just the same, the only difference is the acceleration.
Having said that it started OK from "cold" today (but it is hot outside!)
>
> Has fuel consumption increased suddenly?
>
PC Paul
"ChrisJ" <ch...@youmustbejokingifyouthinkImputtingmyrealaddresshere.com>
wrote in message news:42b72a34$0$3114$ed26...@ptn-nntp-reader01.plus.net...
>
> In each gear 1-3 it revs to approx 4100 and then acceleration is markedly
> less. It may do this in 4th as well but that would be over 70mph I think
> so I can't be sure ;0) as I haven't tested it, honestly. It seems to be
> almost exactly the same in each gear (within 100 rpm). The filter has
> already been replaced to try to alleviate this.
Got it. Obvious really.
They've put a diesel in.
Paul Giverin
<ch...@youmustbejokingifyouthinkImputtingmyrealaddresshere.com> writes
>Tim.. wrote:
>
>>
>> Does the car misfire at all, or is it just holding back ? If its
>missing, or
>> spluttering then you have an ignition problem.
>
>
>It only misfires when "cold and being gutless" pulling away but after
>2-3 minutes it runs smoothly. It runs smoothly above 4000 rpm too
>sounds just the same, the only difference is the acceleration.
>Having said that it started OK from "cold" today (but it is hot outside!)
>
Ok, you say that this problem started only after the car was serviced.
Its possible that the garage have changed the spark plugs, possibly set
the gap too large (Ford reduced the recommended gap on these engines)
and this has put a strain on your HT leads. If you have got your
original HT leads fitted then they will definitely be knackered at 80k
miles.
The Zetec SE engine is very reliable and any problems that do develop
are overwhelmingly down to plugs, HT leads and the coil pack.
Its important that you use genuine Motorcraft leads and either
Motorcraft or NGK plugs. Anything else and you will have more problems
sooner rather than later.
--
Paul Giverin
British Jet Engine Website http://www.britjet.co.uk
Tim..
"Paul Giverin" <pa...@giverin.co.uk> wrote in message
news:YipOP5Fy...@10.0.0.3...
I'm inclined to agree with this at least partially, you cant diagnose faults
like this for sure at a distance, but as Paul says, the HT leads will be
completely shot if they have more than ~60k on them. The surface of the coil
pack needs to be eat-your-dinner-off-it clean and the plugs fresh and
correctly gapped, and the plug wells clean and free from oil too.
It could be a case of the coil pack tracking over its surface to the LT
multiplug or an HT lead flashing to an ECU line which is spiking the ECU and
causing it to shut down / enter LOS mode.
Tim..
Wolverine
if pulling at full throttle, torque reads anything BUT 100%, then it's your throttle positioning sensor. Clean it our or replace it.
--
For full context, visit https://www.motorsforum.com/maintenance-uk/fiesta-1-25-zetec-labours-above-4000-rpm-solutions-56647-.htm
alan_m
> Get a odb2 bluetooth adapter, connect yo your phone and use torque to
> read the throttle position. if pulling at full throttle, torque reads
> anything BUT 100%, then it's your throttle positioning sensor. Clean it
> our or replace it.
>
https://forscan.org/home.html
Both Forscan (for Ford based cars) and the Torque apps are good.
--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk
Tim+
> On 20/04/2023 02:45, Wolverine wrote:
>> Get a odb2 bluetooth adapter, connect yo your phone and use torque to
>> read the throttle position. if pulling at full throttle, torque reads
>> anything BUT 100%, then it's your throttle positioning sensor. Clean it
>> our or replace it.
>>
>
>
> Or a obd2 to usb adapter and use Forscan
> https://forscan.org/home.html
>
> Both Forscan (for Ford based cars) and the Torque apps are good.
Tim
--
Please don't feed the trolls