intermittant 2 cylinder misfire,91 Tsi

[Nathan Craft]

mine's pooched,no spark for cyl. 2&3. if anyone's parting out or has a spare that'd be great.
thanks,
Nate

[Jordan Kruger]

Sounds more like your power transistor. those are the 2 cylinders effected if the transistor fails.  try that first.

[John Hartman]

I agree, try that.

The transistor packs can fail but the coil packs are pretty robust.

Also it could be the ECU as well.

Oh and just to be technically correct, make sure you test your wires and plugs.  IE, run the 1and 4 wires off terminals 2 and 3 and see if they spark.  And try the plugs in the same way.

Also look at the plug in connectors for the coil pack and power transitor too as if they are green and corroded theres your problem.

[Nathan Craft]

I agree, try that.

The transistor packs can fail but the coil packs are pretty robust.

Also it could be the ECU as well.

Oh and just to be technically correct, make sure you test your wires and plugs.  IE, run the 1and 4 wires off terminals 2 and 3 and see if they spark.  And try the plugs in the same way.

Also look at the plug in connectors for the coil pack and power transitor too as if they are green and corroded theres your problem.

any idea if you guys have a pic of that?

[John Hartman]

a pic of what?  My quoted text deals with a number of items. 

if you are referring to the corrosion in a connector, it will be really obvious.  Unplug the device and look at the terminal pins inside the connector both on the part and the wiring harness end.  If the pins are clean and shiny, they are fine.  If they are rusty, dirty, corroded, green etc, they need to be cleaned up individually and then the terminal blown out with air and then some anti-rust spray squirted in the terminal.  WD40 works.

[Nathan Craft]

lol Sorry was in a bit of a rush  Should have been more detailed. The transistor pack, just to see what unit that is. I dont have my shop manual downloaded to my work comp. yet, so I really cant say. but i'll go swap out the wires for 1-4 & 2-3.
The weird this is that it will run normally for a minute or two, then crap out on me. so I'm kinda hoping that is is just a bad connection.

thanks again guys

[Jordan Kruger]

Its a 2 bolt black connector that has 5-7 pins and its located close to the coil packs.     google 1g dsm power transistor.   tons of pics and write ups.

[Nathan Craft]

Checked the transistor pack, everything seems good there. But while I was rootin in there I noticed a small plug with three wires just above the transistor, and one of the wires is hangin on with a single strand. When I disconnect said plug, the engine just dies. But fiddling with it and trying to get a decent connection seems to shortly fix the issue. I'm going in on my day off tomorrow to fix the wire regardless, but I have to pull the fuel rail to do so properly, could this connection be my issue? And what plug is that for? Again it is just above the transistor, and runs under the fuel ral somewhere.

Thanks

[Jordan Kruger]

Ide be willing to go out on a limb and say that is your problem. If the wire has anything to do with power to coils or transistor it will definitely effect the way it runs.  If the voltage is pulsating through a weak connection than it will effect your spark greatly. 

[Nathan Craft]

Well I guess I'll find out tomorrow. I've been trying to figure this out for almost a month of and on. if it turns out that it's just a single wire, I'm gunna be pissed. Happy it's an easy fix, but pissed.

Also mods, can this thread be moved to the garage? Don't want to be a bother, but it would make more use over there

[John Hartman]

that 3 wire plug is for the coil pack, so yea, that will be the culprit.

[Brett Haviland]

yeah... three wires on the coil pack... theres one ground... and the other two controll each coil pack.  One fires 1&4 and another fires 2&3.. if one of those wire is barely holding on and making a intermitant connection it will definalty cause problems.

The connector will be a triangle shape for a 91-94 and on a 1990 (which u dont have) it will be a 4 wire square plug.

[Nathan Craft]

So I have the coil pack pulled off. only have one thing to say.. CAN THEY MAKE IT ANY HARDER TO GET TOO?!? lol but really it's dumb. the wire is now disconnected due to pulling on it, and just waiting on the wreckers to call me back and tell me if they can get another harness plug down to me here. if not i'll just make my own harness.
i'll be adding pics when i get home.

[John Hartman]

you can probably cut a harness off another car and solder/shrink wrap those connections, just make em good and strong.

[Nathan Craft]

well, fixed the harness up, but still no spark, ordered new plug wires. see if that helps.. if not, i guess next step would be the coil pack... getting kinda stumped here..