Focus Fanatics Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
OK, here is the history of my problem:
2003 SVT Focus, 85k mi.
CEL comes on a few days ago, car runs fine. (well maintained car with recent Motorcraft plugs of the right spec.)
Two days ago car starts to run like crap intermittently, then runs poorly full time. No power, rough, noisy idle.
Poking around, I discover the no spark on the 2 and 3 cylinders. Since I had a coil pack fail before in a similar way, I suspected it was the problem and got a new one. No change - still no spark on those cylinders (I did try some other ignition wires and looked at the #2 plug, which looked normal).

Is there some way these cylinders can be 'shut off' by the computer? A friend was supposed to lend me a code reader but he forgot and the local auto parts shops appear to no longer be doing free code readings. Any ideas???
 

·
Premium Member
Joined
·
21,250 Posts
Is there some way these cylinders can be 'shut off' by the computer? A friend was supposed to lend me a code reader but he forgot and the local auto parts shops appear to no longer be doing free code readings. Any ideas???
No, other than the coil pack, plug wires, or plugs.

Did you use a spark plug tester to find out you had no spark?

It's possible that you got a bum part.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #3
No, I deduced no spark in 2 & 3 by disconnecting the wires one at a time (with the engine off, as to not prong anything) . The car runs exactly the same with 2 & 3 disconnected but will not run at all (it presumably does not run on 1 cylinder!) if 1 or 4 are disconnected. Also, I replaced each ignition wire by a new wire in turn and found no difference.
 

·
Premium Member
Joined
·
21,250 Posts
So it could be compression, or fuel, and not spark. There's no reason why the computer would cut off 2 cylinders of fuel or spark. There's not really a good reason why you'd have perfect compression on 1 and 4, but not on 2 and 3. If you have a timing belt problem it would affect all 4 cylinders.

Someone more expert in SVTs will surely come to answer this thread. I'm going to change the thread title so that SVT peeps will look into it.
 

·
Registered
Joined
·
569 Posts
What about the wires that run to the coil pack if there is no signal then there is no spark?
 

·
C2H5OH
Joined
·
11,867 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #7
Thanks everyone for your input.

Thinking about how the coil pack must work:
There are 3 wires coming in.
One must be 12+ and another must be a trigger for firing.
As I understand it, this engine fires sparkplugs 1&4 or 2&3 at the same time.
Would the remaining wire be a signal that switches the spark between cylinders 1&4 and 2&3? A fault in this signal could be my problem.

I'm suspecting the connector/wire....
 

·
Registered
Joined
·
1,474 Posts
Check the wires at the connector for the coil pack, it is a very well known problem for the wires to break right at the plug, and will cause the problem you are describing. Any Ford dealer should have that pigtail plug in stock if you do find the wires broke.
 

·
Registered
Joined
·
131 Posts
OP (jmoryl) is very nearly correct.
The coil pack is actually two separate coils with a common battery feeder. One coil fires plugs 1 & 4 in series, while the other coil fires plugs 2 & 3 in series. The two coils have separate trigger leads coming from the PCM - very likely the one to the coil for plugs 2 & 3 is open circuited.
Good luck,
Monoblanco
 

·
Premium Member
Joined
·
21,250 Posts
I think the new part is bad myself, but check the plug, and the wiring harness for damage just in case. I'd return that coil pack in a minute. It's messed up. You should be able to prove that with a tester by testing the secondary resistance. The secondary being the coil output itself, test for resistance between that and the 3 plug wires. On one of those connections you'll get a reading in ohms on your 1 and 4 coil, and on the other one you won't.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #11
Turns out the new coil was fine.

Yup, it was the connector: the right hand wire was broken right off, but since the broken end was recessed into a hole, it wasn't obvious. Noticing that the official pigtail costs over $30 at a dealer (not wanting to waste more money after buying an unneeded coil pack), and the fact that it was Saturday, I kludged a fix.

Since the leftmost two wires look fine and the rightmost was broken off right at the connector, I screwed a #4 x 1/2" long stainless sheet metal screw right into the connector, penetrating the remaining core of the wire. Sandwiched between the screw head and connector, I placed an eyelet with a connector. Smeared the whole thing with some silicone seal and connected the rightmost wire. Seems to be working fine so far - we will see how long it will hold up! It can't be much less durable than the original.
 

·
Registered
Joined
·
47 Posts
Similar issue so continuing on this thread for continuity

Issue is Number 2 not sparking. 1,3,4 are. I checked at the coil.

Can the ignition coil fail for only one lead (No. 2) ???
 

·
Premium Member
Joined
·
44,595 Posts
Pete - As mentioned above, 1&4 fire together, as do 2&3.

It's called a "Wasted Spark" system, as only one of the sparks is actually needed at the time....

Pretty much standard for a four cylinder engine...

AND, you can't have just one fail as a GENERAL rule, though durn near ANYTHING is "possible"...

Internal fault in the coil, testable by checking resistance between the 2&3 terminals would be the only way just one would fire...
 

·
Registered
Joined
·
47 Posts
Pete - As mentioned above, 1&4 fire together, as do 2&3.

It's called a "Wasted Spark" system, as only one of the sparks is actually needed at the time....

Pretty much standard for a four cylinder engine...

AND, you can't have just one fail as a GENERAL rule, though durn near ANYTHING is "possible"...

Internal fault in the coil, testable by checking resistance between the 2&3 terminals would be the only way just one would fire...
Yeah -- just the No. 2 is not firing off the coil. I will test and/or replace the coil I guess and re-post results. makes me wonder how long the previous owner was running on 3 cylinders. If a long time the o2 sensors, piston rings in 2 and Cat might possibly be hurt as well...
 

·
Registered
Joined
·
301 Posts
So it could be compression, or fuel, and not spark. There's no reason why the computer would cut off 2 cylinders of fuel or spark. There's not really a good reason why you'd have perfect compression on 1 and 4, but not on 2 and 3. If you have a timing belt problem it would affect all 4 cylinders.

Someone more expert in SVTs will surely come to answer this thread. I'm going to change the thread title so that SVT peeps will look into it.
What about a bad head gasket between 2 and 3? Compression test should eliminate that possibility.
 

·
Registered
Joined
·
47 Posts
WOW! What an improvement.

No wonder the CO was high and I couldn't pass the State Emissions Test -- I put a new coil on it and all four cylinders are now firing. As far as I witnessed only ONE terminal was not working on the old coil (No. 2). [???:)]

For the first time I will say that this little Zetec is a great little engine, I wonder how long it's been running on 3 plugs or if the problem was intermittent. It spit out some white exhaust for 3-4 minutes but that went away. I will monitor that closely when I start up tomorrow. Running smooth now with great rev engine response. It even sounds good.

When I received the vehicle it was limping along and was smashed from a highway accident. So far:
New right fender and hood, new ignition coil, new thermostat, platinum plugs, wires, air filter, oil filter, oil change, coolant, fuel filter, replaced ruptured PCV hose, cleaned the MAF sensor (had codes P0113 and P0102). Still to go(as funds permit) : front suspension issues from accident (mandatory) - maybe wheel bearings based on the shudder?, alignment?, brakes?, two new tires, timing belt, maybe tranny fluid replace. This Focus is starting to get in shape.

This ignition coil R&R answered a lot about this engines performance.[thumb]

I'm taking the car back to the State Emissions Test tomorrow to see if it passes.

Wish me luck! [cheers]
 

·
Registered
Joined
·
47 Posts
What about a bad head gasket between 2 and 3? Compression test should eliminate that possibility.
Going to do that too! esp. with the initial exhaust vapors I saw.
 

·
Registered
Joined
·
47 Posts
[offtopic]I drove the ZX3 around yesterday and today -- great little engine. Next of me is front brakes which are currently shot.
 

·
Registered
Joined
·
301 Posts
[offtopic]I drove the ZX3 around yesterday and today -- great little engine. Next of me is front brakes which are currently shot.
Good to hear that you got it running well. And, if you're going to make it 'go' it would make sense to make it 'whoa', otherwise you have a 2,500 lb killing machine. [:)]
 

·
Registered
Joined
·
17 Posts
Hi,

i'v the same problem, no spark on cylinder 1 & 4, changed the coilpack and nothing.

the pigtail connector seems fine :( any ideias? where does the coilpack connect to? directly to the ECU? where is the ECU located?

thanks
I've a 1.6 petrol mk1
 
1 - 20 of 30 Posts
Top