I have a Ford Focus 2016 1 liter Turbocharged, over the past year put in about 4500 dollars, new turbo, new coil packs, new sparks, new cat, etc,
Since July been a rumble at certain RPMs as needle goes down from revving engine needle seems jerky as going down,
So i checked spark plugs, put in myself in June, Prior sparks installed in Jan 2024, Replaced ignition coils too,
Piston 1 spark dirty, looked like black sand material not that much but peppered on threads, top looked ok,
Did pressure test per your video, results:
First try:
piston 1 160
pisotn 2 90
Piston 3 170
Redid piston 2 tighted hose tighter then got 140 on piston two
so:
160
140
170
When I put everyting back, major misfiring on piston 1, very bad.
Standard code P0301, mainly on cylinder 1, when putting pedel down hard, misfires on number 3
Auto transmisstion, about 130000 miles.
Resolved, back to where the car was, 3 new spark plugs on this 3 cylinder engine,
So far this year to resolve misfires had to change sparks in Jan and Jun now Sept.
I looked at the plugs the other day, number 1 as i said was dirty, but after compression test they got even dirtier, probably from excessive fuel in the cylinders after I did the test, no misfires now as of my last test drive. 😀
There are many things that can cause misfires. See if info in the troubleshooting section of the site FAQ helps.
My best guess? Given that you've checked and replaced all those ignition components, and the cylinder has good compression, I'd swap the injectors between 1 and another cylinder and see if the misfire moves to that cylinder.
@glen_stet i do not know how to do, sounds like good idea. will try to learn.
https://www.youtube.com/watch?v=hEIP9ZYnnRc
is Scotty replacing fuel injectors - just search at the top of the Youtube page.
I find it useful to watch more than one - you may find one of these to helpful
https://www.youtube.com/results?search_query=ford+fuel+injector+replacement
https://www.youtube.com/watch?v=hEIP9ZYnnRc
is Scotty replacing fuel injectors - just search at the top of the Youtube page.
I find it useful to watch more than one - you may find one of these to helpful
https://www.youtube.com/results?search_query=ford+fuel+injector+replacement
I have found ChrisFix videos to be pretty good. In this one he shows how to do a quick test on fuel injectors
https://www.youtube.com/watch?v=tA_E6X4ISgQ&t=127s
Did pressure test per your video, results:
First try:
piston 1 160
pisotn 2 90
Piston 3 170Redid piston 2 tighted hose tighter then got 140 on piston two
so:
160
140
170
Cylinder 2 is worn. The wear should be within 10% of the highest value in your compression test, 140 PSI differs from 170 PSI by 18%. You can't correct this unless you rebuild the engine.
Ensure your spark plugs are tight and there is no cross-threading.
I had an issue with misfiring in my '79 Catalina a couple years ago. It would only misfire when cold. When it's warmed up, it was fine. I had changed the spark plugs 4 months prior and a couple had wiggled loose. They sealed when the engine got hot. That car has a V8, not an I3.
Providing you used OEM coils and a turbo, a spark plug could have wiggled loose. That's the only explanation I can think of.
Have you checked the head gasket?
@fishingandcarsenthusiast123 No, I do not know how to do that, that is why I did the pressure test today, got the test for 30 bucks and was under the impression that would reveal head gasket issue.
One thing I should probably mention, over the past several months the battery indicator light on the dash would go on and off. Brought to a ford dealer, paid 200 dollars for diagnostic (June) , they said first a pinched wire, then when I asked again for clarification last week, manager said replaced wire behind dash.
But last week the alternator finally went bust, car would not start, paid 800, back to running.
I switched ignition coil in cyl 1 to cyl 2, and put ignition coil #2 in #1 position, reset computer, same P0301, so I guess it is not the ignition coil, tommorrow I am picking up some ignition coils I have a newer one in garage and I bought a new one today from advanced auto parts,
and will replace all spark plugs, if same thing happens then what do I do then, compression test seems ok.
Why are you purchasing new ignition coils if you determined that is not the problem? @crawfordjohn
You right, I did not logically think this out. But I have had 2 episodes before of misfires and each time putting in new ignition coil resolved the problem. Bottom line, sometimes the problem is the coil, other times the spark or could even be both. I will probably by Ford OEM units soon and burn the cash because the units from AutoZone and advanced auto p are from china probably same manufacturing plant, they have the same plastic mold to a T,
When I did the compression test I did not disconnect the fuel line as, did I ruin my engine??
@crawfordjohn No.
the units from AutoZone and advanced auto p are from china probably same manufacturing plant,
Never buy ignition coils from your auto parts store, as they often sell cheap Chinese junk, like you mentioned. Always be sure to buy OEM ignition coils. They'll cost more now but at least you'll get more time out of your engine.