mk1 focus down on power but no codes /lights

[steveo3002]

maybe some dud fuel ? pulling the timing back?

 

[the snooper]

if yours doesn't have a maf it should have a map sensor which is manifold absolute pressure, I would be looking for any tiny vacuum pipes and fittings that have perished causing an air leak

 

[pedrobedro]

When the sensor went on our car I found it went better with it disconnected till I got a replacement. Just disconnect it and try it but keep an eye out for fault light (ours didn't throw one up but it's a Citroen)

 

[Richard.]

A Google image search suggests it's tucked behind the manifold of all places.

 

[Richard.]

That's a mk1 1.6 ztec.

 

[Richard.]

When the sensor went on our car I found it went better with it disconnected till I got a replacement. Just disconnect it and try it but keep an eye out for fault light (ours didn't throw one up but it's a Citroen)

I also found this on a mark 4 tdi golf that was running bad. Unplugged the sensor and tied it out the way and it was as good as gold.

 

[the snooper]

A Google image search suggests it's tucked behind the manifold of all places.

google images has it wrong, the maf has to be on the air intake for all cylinders

 

[steveo3002]

ok will see what happens with it unplugged...wouldnt it show a dash light or fault on the scanner tho?

 

[Richard.]

google images has it wrong, the maf has to be on the air intake for all cylinders

I know it' has to be on the air intake. I didn't know if the intake went round the back there or not.

 

[Richard.]

ok will see what happens with it unplugged...wouldnt it show a dash light or fault on the scanner tho?

Not always.

 

[the snooper]

I know it' has to be on the air intake. I didn't know if the intake went round the back there or not.

ive just looked at the text associated with that pic and the guy didn't have a clue and was just suggesting that he thought it could be the maf, but the focus without maf uses the map senor

 

[steveo3002]

so disconect the map then or what ? what does that do

 

[Richard.]

ive just looked at the text associated with that pic and the guy didn't have a clue and was just suggesting that he thought it could be the maf, but the focus without maf uses the map senor

I didn't get that far.
Ok. Assuming it may not have one. Does it have a lamda sensor?
Now I know from personal experience that can cause the symptoms you describe. Gutless at low rpm.

 

[the snooper]

so disconect the map then or what ? what does that do

no I wouldn't disconnect it, I was just pointing out that it would have one, if no codes are shown it would suggest the sensors are working, will your code reader show live data ?

 

[Richard.]

Lamda will be sat on the front pipe most likely. Have it plugged in mate. Some time on these older cars the light doesn't pop up even though there is a code fault.

 

[pedrobedro]

Disconnect it and try it round the block, you have nothing to lose and if it doesn't throw a code up like ours just replace the sensor and get it checked for codes at your convenience.

 

[Richard.]

It's a 12 year old motor with 100k on the clock. Who's to know if the dash light even works properly. Id have it plugged in to at least see if you have any fault codes and go from there.

 

[steveo3002]

like it says on the title...no fault codes

 

[the snooper]

It's a 12 year old motor with 100k on the clock. Who's to know if the dash light even works properly. Id have it plugged in to at least see if you have any fault codes and go from there.

they self test when you start the car

 

[Kayos]

I had a Mk3 Astra years ago with a very similar problem, tried lots of stuff to no avail

In the end it was the fuel pump relay, contacts had arced and gone high resistance, new relay from the scrappies sorted it