Running on 3 cylinder??

alright guys, this is just to make sure i am on the right track.
First, today while i was driving and on boost, almost like boost cut, i lost power. But was still running rough(driveable).
I thought piping came off at first. Second, not sure if something is seriously wrong, but my vacuum hose to FPR have intermitten vac pressure.
I noticed this by my Fuel Pressure gauge not moving. Staying at the same pressure with both vac connected and disconnected.
but it would come back.
Finally, thinking it was a boost leak(not probable because recent dyno showed strong boost and it held)but it wasnt.
So, I just did my usual test by disconnecting each plug wires while car is running rough, and found that the #3 cylinder had no spark!
but my #1 had spark. only on #3. So after reading up on the diagram of the iginition system. I dont think its the transistor or ecu.
The problem would be #3 spark coil. I drove the car all the way home just fine. just not that powerful or smooth idle.
does this sound right or am I missing something?

 

[turbowop]

If the FPR solenoid is still connected, during the first few minutes of running it won't allow vacuum to the FPR. This could be your "intermittent" issue with that.

 

thanks, I dont know where my solenoid is located?
Is the vacuum off of my AEM FPR somehow connected to the soleniod?
I know the vac comes from the intake manifold.

 

[turbowop]

If the vacuum line off the FPR goes directly to the intake manifold or tees into another vacuum line that goes directly to teh intake, then you don't have the FPR solenoid anymore. If the vacuum line goes from the FPR to a solenoid which is normally located on the firewall, then you still have it.

 

thanks!
But I'm still curious on if my problem is the #3 cylinder coil?
I'm hoping new coil will fix the problem.
I dont feel like replacing something thats not broken.
I do not believe its the ecu or transistor for the fact that only #3 doesnt have spark.

 

[turbowop]

Have you pulled the spark plug to see what it looks like first?

 

yes, of course.
it looked wet! but thats after couple hours of cool down.
at idle, parked at the church, you can smell the fuel much more. Its gotta be from #3 cylinder not igniting.
could it be the plug wire?
If the problem remains after coil swap, I will swap plug wires and see how that reacts.
I hope its something simple as coil.
I heard nightmares about ignition problem on dsm..
I am also going to keep extra parts for the future.

 

[turbowop]

Compression test it. Best way to find out if you have big problems or little problems.

 

Well, that's a little strange, because (unless you have COP) the same coil that drives #3 also drives cylinder #2. What happens if you swap them?

 

I dont see a reason for a compression test.
I know for fact, #3 doesnt get spark. I pulled the plug from left to right. first wire pulled, got spark. I heard it arc and engine runs really rough. did it to next one and no change in engine idle or smoothness. check for spark. nothing! did it to remaining two plug wires and spark was present with rougher engine idle from spark loss when disconnected.

If(I dont know this for sure?) the coil that is mated with other cylinder can go bad seperately, (4123) 4&1 and 2&3 for each coil, so #2 side of the coil is still good but not #3, problem should be solved by replacing the coil.

Keydiver, I wasnt just going to swap the 2 and 3. I will just swap the #1 cylinder plug wire with the #3 to make sure its not the plug wire issue.
keeping the ignition timing the same of course.
I have removed the coil and try to find the way to test it. no luck. I will replace the coil on 2&3 side and crank the bad boy back up.
although the engine runs rough, I didnt have any problem starting the gvr4. I drove all the way 20miles without an issue. just no boost.
Again, I thought I may have pop the intercooler pipe at first. because i was boostin when it occur. So I can understand how someone can think that its engine related. I am pretty sure if I have spark on #3. car will run fine. it was still boostin on 3 cylinder driving home. not that I was trying.

 

Our cars use a "wasted spark" system, which means that it is actually firing cylinder 2 and 3 both at the same time. That's why I suggested swapping them at the coil, to see if you then see any spark at cylinder #3. The 2 plug wires actually come off opposite ends of the same transformer winding, if I recall, so I suppose it would be possible for there to be an internal short that would keep #3 from firing but #2 would still be OK.

 

Thanks. I am only having one spark missing. So I am hoping that its the coil on #3 side that went bad.
unless there is something else that controls this seperately?
From the diagram, signal/pulse from the ecu is sent for two cylinders. So if I am getting spark at other cylinder, that tells me that the wiring is still good. More to come after I go pick up a coil.

 

problem fixed with a new(used part)coil pack.
I guess the coil pack can go back on only one side of the coil plug..