The damn car sounds like a 2 stroke dirt bike!! I was driving down the highway, stopped, pulled into the the mall ( to turn around) , the car was running great!...stopped at a red light, idled OK, when the light turned green, I hit the gas and the car just crapped out. Got it home, pulled the IDI cover, checked the plugs, two good, two BLACK. Flipped the IDI cover upside down, inserted plugs, grounded the plugs with a wire, cranked over car....LOTS of spark. Tested the injectors with my DMM and are all OK...tested the wiring for the injectors back to the BCM....OK, What the hell am I missing. I have spark, fuel, and air.....what else does this car want???
This somewhat happened before, but with one cyl. not firing. Changed the crank sensor, and solved the problem.....could this be of the same nature???



If at first you don't succeed, destroy all evidence you tried!

Oh...forgot to tell you.............CEL was flashing ( missfire condition )


If at first you don't succeed, destroy all evidence you tried!

Maybe a coil? They're only like $30 @ AutoZone, and worth a try.

Flipped the IDI cover upside down, inserted plugs, grounded the plugs with a wire, cranked over car....LOTS of spark. I think this would mean the coils are good???
Any other suggestions


If at first you don't succeed, destroy all evidence you tried!

Ahhh... yep, you're right. Forgot about that... I don't know man.

Flipped the IDI cover upside down, inserted plugs, grounded the plugs with a wire, cranked over car....LOTS of spark. I think this would mean the coils are good???

not necessarily. when you make them fire this way there is nothing fighting the spark plug as it tries to make the spark. when the plug is in the cylinder the compression fights against the plugs attempt to fire...which is why it requires such a strong voltage to fire it off. what you need to do is go buy a spark tester. it has a recessed center electrode which better simulates the situation in the cylinder. only a few bucks too. i bet if you get one of those the spark looks A LOT different.



I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26

OK I see your point. I switched the coils around to see what happens, and the same two cylinders are not firing. Which would lead to a good coil wouldn't it, as they both fire
the other cylinders when switched around?


If at first you don't succeed, destroy all evidence you tried!

Yes if you switched them around, more than likely the coil is good. But that doesn't say the module isn't faulty. I forget how the ignition is set up, but either way which cylinders are not firing??
Also I don't really see it being the crank sensor again, if you have a spark(even if it ain't great)..the crank sensor is still giving signal as to when to fire for each cylinder

1 and 2 ARE firing, 3 and 4 are NOT firing.....this is a new one for me??? got me baffled! I think I have the very first 1.2L GM engine...HA!! Anyway...any suggestions?


If at first you don't succeed, destroy all evidence you tried!

It's a wierd one because there not sister cylinders 1-4 and 2-3 are sisters..so that knocksout the coils ..plus you swapped position for the coils and the same fault is present. Have you tried changing the spark plugs around, like remove 1&2 and fit them as 3&4 kinda thing..same with the little boots as well. It's gotta be something stupid that we're missing

Yup....switched the plugs, and boots.....same problem. If I start the car, it runs on 2 cylinders ( 1 & 2 ) and the exhaust reaks of fuel....if I unplug the injectors to cyl 3 & 4 the smell of fuel dissapears from the exhaust, and the car keeps running on 1 & 2.
So this tells me I have fuel, previous tests tell me i have Spark, and air.....is there a new way to allow combustion that this engine invented? lol.


If at first you don't succeed, destroy all evidence you tried!

has anyone done a compression check on the cylinders to see if it maybe bent a valve or to or to see if a cam wiped out. anything is possible. do a compression check see what you have there.



2009 Ford Mustang V6

Compression check is good on all cylinders. This is leading me to a PCM problem...what do you guys think?????


If at first you don't succeed, destroy all evidence you tried!

I can't see how the pcm can control this, there are 2 wires coming from the pcm to the ignition module. these 2 wires are each running 2 cylinder, only thing is there each running sister cylinders..remember its a wasted spark system. So 1 wire sends feed for 1&4 and the other 2&3. If one of the wires goes bad or even corroded terminals at the pcm wtv the case..you would have 2 sister cylinders not function
In your case you have both sister cylinders not working.
I could be wrong..but i remember looking at a wiring diagram for the ld9, and thats pretty much what i could figure out
But with wasted spark in mind, your getting spark to on all cyl..but you could be seeing the wasted spark on 3-4 and thinking it's working, but it's not. If the crank sensor doesn't signal 3-4 to fire at its correct time..volla 3-4 don't fire until it gets the wasted spark from 1-2. Sorry if this doesn't make any sense, hehe ..becasue i'm hung over

Well I give up!! Not enough time to fart around with this and too many beer to drink!! My buddy owns a tow truck, so yes, it's parked at the shop waiting for the mechanics to come in on Tuesday. ( Damn long weekends! ) Thanks for your help anyway. I do know what you mean about wasted spark, and as for your hangover, can't help you there!! lol.
You know what they say " no pitty for self inflicted pain" ha ha!!


If at first you don't succeed, destroy all evidence you tried!

Anyone think that it could be in the valve train???? Is there lifters in there???? I hope it's not a broken cam shaft!!! maby a bent valve???


If at first you don't succeed, destroy all evidence you tried!

Guess you could call them lifters, there like little buckets on top of the valve stem. The lobes push on the buckets and then buckets force down on the springs.
Bent valve can cause this, but if you have compression within spec then i don't see it being a issue.
If you had something broken like a camshaft, i think you'd be worried more about the noise it would be causing, instead of why it missfires.
If you have a wiring diagram, there's one in the haynes manual..even the chillton.
Follow through the wiring, check for corrosion and any breaks in the wire..even a pinched wire/harness can cause this. That means from pcm, the cam and crank sensors, to ignition module..anything related to running the motor, make sure all wiring is intact and well.
If you have compression within spec and no abnormal noises(besides missfire), then your looking for some sort of electrical problem. ..but not a pcm problem, for it to be a pcm fault you would have to have 1&4 or 2&3 not firing

I guess if it was mechanical, there would be a hell of a lot of noise. It's quiet, except for the missfires..You are prolly right,,,wiring.....I'll let you know..


If at first you don't succeed, destroy all evidence you tried!

IF I look at the ignition module....the white wire fires 1 & 3 and the purple/white wire fires 2 & 4. They both seem to have the same voltage when the car is running. With the car off, they both have the same resistance from the ign. mod. connector to the PCM. Connector.


If at first you don't succeed, destroy all evidence you tried!

Ok right now I'm looking at a diagram out of the haynes manual(not the greatest but for now). It shows a orange wire from pcm to ign ctrl module for 2-3, then a wht wire from the pcm to the ign ctrl module for 1-4. The wht/purple wire on my diagram is a ref signal

The haynes diagram doesn't state a year, so don't bust your self if what i'm saying doesn't match up....just shows 2.4L, plus haynes have been incorrect

EdgeZ24 wrote:Ok right now I'm looking at a diagram out of the haynes manual(not the greatest but for now). It shows a orange wire from pcm to ign ctrl module for 2-3, then a wht wire from the pcm to the ign ctrl module for 1-4. The wht/purple wire on my diagram is a ref signal

loudsound wrote:
IF I look at the ignition module....the white wire fires 1 & 3 and the purple/white wire fires 2 & 4. They both seem to have the same voltage when the car is running. With the car off, they both have the same resistance from the ign. mod. connector to the PCM. Connector.

Was this a slip, Loudsound, or is that what really happens?



So, 1-4 and 2-3 is the correct firing order?

If it really is firing 1 -3 and 2-4 surely that's the problem

I would like to know what it was?


Alont

It can't be 1-3 and 2-4 becasue the firing order is like most 4cyl engines: 1-3-4-2. If 1-3 were sisters then the coil wouldn't have enough time to charge up correctly. Tthat being said it would have to be 1-4 and 2-3 for the two wires

oh yes...your right...it is a "slip"....1-4 white and 2-3 purple/white.....I got my numbers mixed up.....NOT 1-3, 2-4.....the orange is battery power, and the pink is ignition power, black/white is ground, not sure about the rest.....at least they are on my car.


If at first you don't succeed, destroy all evidence you tried!

ok...just got off the phone with the shop......double checked compression...195 across the board.....changed the spark plugs ( DUH!! ) and solved the 3 & 4 problem, but now it's got a missfire on 2....they think it is injector related....this car must be posessed!!!


If at first you don't succeed, destroy all evidence you tried!