Reduced Power + Testing

[sonic113]

Just may have a little fault with the focus. 1.6 2009 zetec. Noticed the past few days tat it feels like it is lacking a bit of power especially on the hills. I have ran forscan with no DTC codes appearing.

Car was serviced back in June so all looks good in terms of filters and plugs ect. Car is idling 100% I was thinking maybe a new coil back but is there any way I can test this with forscan or a multimeter see before I swap anything about. Also would like to try to test the throttle position sensor to see if its ok so any way to test this would be great.

Basically symptoms are car runs 100% idling and taking off but when I put accelerator to floor its flat and then picks up also if I gently pump the accelerator I can feel a lot more response from the car and it feels lighter of that makes sense. I have also been reading about fuel tank vacuum hoses can get blocked which reduces fuel goin to the engine but not sure on this one so any advice or tests you can think of fire away.

:)

Thanks

[Russ]

Check the resistance of your plug leads in case one has 'gone', I drove for about a year with an annoying hesitancy that felt like a very very light misfire that I could only feel at a certain RPM, changed air filter & plugs but it was still there, then used a meter on the leads, it was only then that I found the lead to cylinder 3 had no resistance at all, one set of leads later it was all perfect again.

[sonic113]

Thanks Russ for replying. I never thought of checking the spark leads as I would of thought if any one was faulty I would get a misfire at idle and when I rev it at idle? anyway does no harm to check it out. Its annoying because car drives well only for this little issue.

I found a you tube video of a guy testing leads

https://www.youtube.com/watch?v=4_EFGAFxi1w

would this work for my spark leads or do you have a better suggestion. what should I be looking for in the test for each lead?

what kind of mileage would the spark leads and coil be normally changed at?

[Russ]

Here's a good description explaining how to test the leads, if you find one that doesn't give any reading then that's a bad one. https://www.ngk.de/en/technology-in-detail/ignition-cables/diagnosis/testing-of-ignition-cables/

The plugs and leads I normally change Every 3 years (or sooner if your doing a high mileage) and the coil could last the life of the car or it can break down at any point ( it went on my fiesta at 35,000 miles and was replaced with an OEM one which was still ok when we sold the car with 101,5000 miles on it in March) it's just the luck of the draw.

When I change ours I'll be buying bosche super4 plugs as I used them on our fiesta and had no problems, throttle felt sharper as well.

[sonic113]

Here's a good description explaining how to test the leads, if you find one that doesn't give any reading then that's a bad one. https://www.ngk.de/en/technology-in-detail/ignition-cables/diagnosis/testing-of-ignition-cables/

The plugs and leads I normally change Every 3 years (or sooner if your doing a high mileage) and the coil could last the life of the car or it can break down at any point ( it went on my fiesta at 35,000 miles and was replaced with an OEM one which was still ok when we sold the car with 101,5000 miles on it in March) it's just the luck of the draw.

When I change ours I'll be buying bosche super4 plugs as I used them on our fiesta and had no problems, throttle felt sharper as well.

Thanks Russ,

I'm currently awaiting a new multimeter as my old one got broken and is no use so when it arrives I will use that guide to test the leads and see where I am from there. I will keep this updated as it may help others. :)

[sonic113]

Ok got the new multi meter and tested the leads this morning.

first of all I inspected the leads for damage ect all seems fine.

Upon testing the resistance of the leads I got the following readings. I'm getting used to the new meter as I think its an auto range one but with it in in ohms I got the following.

Cyl 1 Lead 8.1

Cyl2 Lead 6.2

Cyl 3 Lead 4.1

Cyl 4 Lead 2.8

Does this look about right?

any feedback is welcomed.