4k hesitation at WOT

[davidgt97]

First of all I am a newb so I don't know how to use the site perfectly yet. I have tried researching it but it seems everyone's problem is a little different than mine. I have a 93 Talon Tsi. I just bought it yesterday for $1800 but it is far from perfect. If I drive the car around 1/2 throttle it seems to pull very well and according to the stock boost guage it boosts well through all gears. The problem is at WOT. When I take off in 1st somewhere around 4k the car begins to hesitate horribly. It revs slowly but boost still appears fine. This is the same through 2nd and 3rd. I was on the highway yesterday and up steep hills in 5th I could feed it just a little gas and it pulled very well. Please, any advice would be great. I have plugs and wires ordered but if that doesn't work I'm stumped.

 

[davidgt97]

Well since no one had any ideas I decided to throw some money at it and started replacing little things. plugs, wires, fuel filter, PCV valve(blowing dipstick), blowoff recirculation hose(appeared to be cracking). I also Sea Foamed the main vacuum from the brake booster and it smoked horribly. With all this it did improve considerably but it is still sluggish and maybe a little hesitant, especially in 1st gear. Also while doing the Sea Foam I noticed as it smoked heavily from the tail pipe it did smoke some from under the heat shield. I'm guessing cracked manifold. Again any ideas would be great. I am planning on getting a logger soon, but there's no substitute for experience. Also I do have a good boost guage laying around. Where do I "T" it in?

 

[KazooGS-T]

You can tee the boost gauge from any vacuum source on the intake manifold, or intake. I would say that your hesitation is from a boost leak. A common place is from the couplers on the smic or from the throttle adjustment screw; or the bov. Or, the bov flange mating surface itself. Also, you most likely do have a few cracks in the manifold. You can either weld them, or you can purchase a new manifold, like an evoIII manifold. Good luck

 

[davidgt97]

First of all, thanks to KazooGS-T. I have purchased a stainless manifold of EBAY for $120 shipped. I also rigged my own boost leak test kit out of some 2" pvc, pvc caps, and a thread in air fittinng. I started by trying to fill the lines w/ 15psi. No luck. I could hear the air moving and could build no pressure in the line. I pinpointed the sound to the BOV recirc. hose, removed it, and found my enormous leak. So I guess I need to start w/ buying a new BOV.

 

[KazooGS-T]

Ah, I wish you good luck with the car. As far as the Bov goes, I have another stock 1st gen that I could get to you. PM me if interested.