00 Focus 1.6 Missing/hesitating under load

magher

Recently the car has started to miss/stutter low down in the rev range >2000rpm in 2nd & 3rd gear when you give it gas. For example, after crossing a speed bump in third, it misses when accelerating away from 1200 to 2000 rpm, and is fine after that usually.

Previously it had a rough idle when warm, where it would hunt between 500 & 800 rpm. I replaced the plugs with the same type that were in it, AYFS22C. But it turned out these were for the 1.8 & 2.0 focus. The 1.4 & 1.6 should have AZFS22C (1.3mm) So I widened the gaps from 1.0 to 1.3 and fitted them and the idle is now steady.

The only thing I noticed was the lead on plug #2 was quite loose and the contact on that plug was corroded (greenish) more than the others, and the electrode were in better condition, indicating that it never sparked as often as the others maybe? This lead is a bit dodgy and doesn't quite click into place as well as the others, but it doesn't come loose.

Anything else I should try? I have the torque app working with the car, but no fault codes are being recorded.

Car just passed 100,000 miles so was due a plugs change.

Cheers

Bejubby

Could be the leads have seen their best,especially if they are original.

emeldc

Are you saying the plugs haven't been changed in 100k :eek:

magher

Bought it with 80k, someone me told the plugs did 100k. Turns out he was wrong, the iridium's do 100k, coppers do 10k!

Car is actually behaving a lot better now. Thinking it may be because the ECU reset when the battery was disconnected, and now its relearning the fuel trims.

whizbang

Best way to test HT leads:

Use a spray bottle that makes a fine mist of water, spray it over all the HT leads at night. (engine running!)
Any faults will make lovely blue glow .

Cogsy88

I'd say it's the coil pack. A common problem with that model focus. Replace the coil pack, leads and plugs. My auto factors do it as a set because it's such a common problem.

greasepalm

hahaha same issue here on 1.4,no faults but air hose/breather pipe under manifold collapsed no splits as in drawing in air but replaced.coil and lead set lucas was replaced but noticed only 2 screws inserted as 2 other holes dont line up,might get another coil to check or maybe fuel pump pressure needs looking at,emissions ok.

Cogsy88

greasepalm wrote: »

hahaha same issue here on 1.4,no faults but air hose/breather pipe under manifold collapsed no splits as in drawing in air but replaced.coil and lead set lucas was replaced but noticed only 2 screws inserted as 2 other holes dont line up,might get another coil to check or maybe fuel pump pressure needs looking at,emissions ok.

That breather pipe is also a common problem. Sounds like the wrong coil pack was fitted. There is two different ones for the 1.4 Did you change the plugs as well? Could also be the air flow meter.

greasepalm

only know of 2 coil packs both have different plugs,dont think the ford plugs were changed as flash over is seen on plugs usually old ,in tomorrow for better looking at,have 1 coil sitting on desk and with my luck wrong one lol.

greasepalm

dam had car in late friday afternoon ,replaced whole kit ,plugs ,leads,coil same issue,petrol flow was good but no tool for pressure checking.

magher

Problem solved, cylinder No.2 HT lead was loose/cracked. Replaced with cheap set from motor factors, €28 for full set.

greasepalm

cheapskate lucky you,glad your sorted.