Problem: Full throttle, high rpm engine cut

[Catbox_95]

The car - 1998 Eagle Talon Tsi awd, all stock engine, auto transmission, boost gauge installed, air filter, 3" exhaust, no cat. The rest is completely stock.

I've been chasing this problem for months now and I'm running out of ideas. Here's what's going on:

When I hit full throttle, as soon as the engine reaches full boost it cuts out, and sounds much like a stutter box with loud popping. First gear does it the worst. Second gear does it too, slightly not as bad. Third gear as well, but again, less prominent. But overall it's bad, loud and definitely not right.

I was chasing a small problem which led to this. There had always been an unsmoothness about the car, and I was trying to figure that out. One of the things I ended up replacing was the coil packs. Immediately after replacing them, with a brand new pair, is when the above mentioned bad problem began. One might think that the brand new coils were bad, and I guess that's a possibility, but I want to exhaust all other possibilities first.

Here's a list of things I've done so far:

Boost / Vacuum leak test
Plugs, plugs and more plugs (NGK BPR6ES gapped to .030, .028 and .026)
Replaced fuel filter
Replaced fuel injector seals (they had a slight leak)
Replaced coils (which is when the problem began)

Plug wires are in the mail and should be here tomorrow, so I can try that. If I replace them and it still does it, I might try and put the old coils back on. Does anyone else have any other ideas? Thanks in advance.

 

[JwpRider]

"Immediately after replacing them, with a brand new pair, is when the above mentioned bad problem began".

I would swap the other (old) coil packs back in and see what happens. If your 'small problem' returns and fixes the larger, stuttering issue then you may be onto something. Is it possible you have the coil wires crossed? Or as you suggest, maybe just a bad, new coil pack. Just an idea to try...

 

[laserspeeddemon]

Just cause you bought it new doesn't mean it will work fine. It could be a manufactures defect. Did you got OEM or aftermarket?

 

[Catbox_95]

Well, I received the new plug wires and installed them, and still had the problem. So I took the new coils off, and put the old ones on, and....... Yyyyyup - That was it. Brand new (aftermarket, O'Reilly) coils, no good. I've been chasing this rabbit for over a month now so yes, I was excited. And O'Reilly took the coils back so I got my $220 back.

The good news is, in the process of chasing down the larger problem, I have apparently fixed the smaller nagging problem that began this journey in the first place. My guess is somewhere between the small leak in the injector seals, and the old worn out plug wires. Either way, all is good now, so I can begin the long-awaited plans I've had for it.