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Discussion Starter #1
Hello all,

I have just acquired a mk1 (98) ford focus that has a 1.8 petrol engine.

My problem is that if I put my foot down the engine will die to low revs and struggles to accelerate. If I keep my foot down it will 'chug' along build a little then die again and will continue to do so. If I ease off the accelerator to around halfway it will drive reasonably normal. The problem is allot more apparent when under load.


Things I have checked by replacing them with parts from a known working focus are:-

spark plugs
leads
air flow sensor*
coil pack
New fuel filter

I have also tried to eliminate the cat by dropping it from the manifold as I believe this will allow the pressure to escape if it was blocked but no change!


*If I remove the airflow sensor from the intake system the focus will rev fully without cutting out but wont have the power it would normally have I assume because it has been removed; maybe this is why it doesn't die though as it wont be at full power?


I have connected to a standard obd11 diag machine but doesn't show any fault codes.

I am almost at the point of changing the fuel pump, but would this be the problem here? I personally cannot see why this would be an issue if it does rev when not under load and also revs fully if not 'floored'

I am running out of ideas so hoping somebody can give me suggestions to what it could be.

All help appreciated and will keep posting with updates
 

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Well, the best solution to a problem is usually the simplest, so i'd take a long, hard look at that airflow sensor before you embarked on a mission to replace the fuel pump. The Airflow sensor is reasonably inexpensive, and takes roughly 10 minutes to replace; Whereas the Fuel pump takes a full day to replace, and is considerably more costly.


Just a thought,
-Aaron
 

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Discussion Starter #3
Well, the best solution to a problem is usually the simplest, so i'd take a long, hard look at that airflow sensor before you embarked on a mission to replace the fuel pump. The Airflow sensor is reasonably inexpensive, and takes roughly 10 minutes to replace; Whereas the Fuel pump takes a full day to replace, and is considerably more costly.


Just a thought,
-Aaron
Agree, I don't want to touch the pump to be honest especially as I cant see it being that but I have swapped the maff over with my m8's car and it didn't change the symptoms one bit!
 

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Vacuum leak.
When you floor it, there is just not enough suck. Maybe a top intake header gasket leak. or some other part of the upper air track is leaking a bit.
Little engines do not like to have WOT at low RPM anyway, so even a little flaw will make it just die.
This from a 62 year old bag, so take it with a grain o' salt. [nutkick]
 

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Discussion Starter #5
Vacuum leak.
When you floor it, there is just not enough suck. Maybe a top intake header gasket leak. or some other part of the upper air track is leaking a bit.
Little engines do not like to have WOT at low RPM anyway, so even a little flaw will make it just die.
This from a 62 year old bag, so take it with a grain o' salt. [nutkick]
I will check again for vacuum leaks as I can see your theory but not sure about the WOT being a problem, I have never driven a car that dies if I stick the pedal to the metal. I can can take a 1.2 punto and floor it with no problems so doubt that a 1.8 focus would suffer to this extreme from WOT
 

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could be tps.

also check all the pig tails going to the sensors for damaged wires or loose pins.


and it there any codes?
 

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Discussion Starter #9
clogged catilitic converter?
Yea did think this, I had an Astra with the same symptoms and to diagnose this I remove the lambada sensor to allow for the gasses to escape and it cured it, so tried this with this car and even dropped the cat from the manifold but no change so v.doubtful.
 

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Discussion Starter #10
Problem Solved

Solved!

Ater a few hours of checking pipes etc I bit the bullet and changed the petrol pump,
. A bitch o a job as you have to remove the tank when they could of been friendly and cut a hatch in the rear seat like some of the better manufactures would but never mind. Took just under two hours to do, putting it back is harder than removing but at least when changed the problem is solved!


So if your car has issues with WOT and you have checked all of the above solution.... Fuel pump.
 
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