Hi.

So had rough idle and loss of power when putting foot down hard when warm.

Found a collapsed rear PCV hose and one of those manifold blanking plates had a whole in it. thats done and the idle appears better but also found out after that was replaced that the fuel vapour solenoid is faulty. With it connected (its stuck open) in addition to the no power problem it will cut out. With it blocked of it idles ok (ordering a replacement, filter inside just crumbled)

Just before this it was puling like a train - always has. Execept for the rough idle which I now assume was the split PCV pipe.

SO far have done the following but its still juddering under load, idle forever (around 700rpm) it seems without issue and start on the button.

Fuel pressure checked, meter connected and all stable and good.

PCV valve checked - seems ok

PCV rear hose replaced

Inlet bungs under inlet breather hose both replaced with fresh

Coil replaced (delphi) and refitted old one again just to check new coil wasnt duff.

New bosch plugs and gapped

New ignition leads fitted

Unplugged MAF sensor and drove (it felt rougher when unplugged and better when plugged back in so assume this crude test it working)

New air filter

Leak/smoke test - nothing found after replacing PCV hose and bungs.

No EML or codes coming up (only the free app)

Coil pigtail looks all good

Throttle body cleaned fully

Battery fully charged and earthed ok it seems. Battery removed to reset.

Did a crude compression test and it peaks 165......but it was only sealing rubber gauge to top of cylinder hole.

No signs of overheating or HG gone. Dosnt lose oil or water.

MOT completed 5 weeks/400 ago and no indication of bad gases/sensor playing up.

Just dont really know where to go from here. Dont really think its worth disturbing the ICV as it ticks over fine.

Will be doing proper compression test within next few days and have a fuel vapour valve coming.

 

 

 

 

Damaged/blocked catalyst?

Sticking valve(s) ?

Worn/broken valve spring?

It looks like you've tried everything else

Not a long shot but because you stated you fully cleaned the throttle body did you follow it up with a throttle re-learn? I'm only saying because I had similar with my last car after I cleaned the throttle body. After the re-learn all was fine.

Which model Focus do you have? Is there a multi-plug attached to the throttle body? Did you disconnect it before you started to clean it?

2 hours ago, DaveT70 said:

Damaged/blocked catalyst?

Sticking valve(s) ?

Worn/broken valve spring?

It looks like you've tried everything else

Hopefully after we do a proper compression test tomorrow we should see this.

2 hours ago, tazzman600 said:

Not a long shot but because you stated you fully cleaned the throttle body did you follow it up with a throttle re-learn? I'm only saying because I had similar with my last car after I cleaned the throttle body. After the re-learn all was fine.

Which model Focus do you have? Is there a multi-plug attached to the throttle body? Did you disconnect it before you started to clean it?

So its a zetec 1.8 on a W plate.

I'm not sure we unclipped that plug whilst we were cleaning it to be honest but it wasnt removed from the car just thoroughly cleaned both sides using ECC. Cant remember if we've had the battery off since but its worth a try.

Well we think its bad petrol with some condensation in it. Compression test was fine. Only thing left and now the cars likely a scrapper 😞