ok so i have a 03 evo 8 with tbe, lower ic pipe, mbc, fuel pump, evo9 turbo with megan 02 housing running 24-25 pounds of boost and a tune. i recently started getting this problem where when i would pull hard from any gear but usually 1st to 2ed it will pull strong all the through till 7 k then after i shift the car bogs for a split second as if i had just let off the gas but then starts going again. Im at a loss here ive ruled out boost cuts and clutch because one the engine doesnt rev up when this happens it feels more like a lack of fuel type thing. and i dont think its boost cuts because it pulls perfect all the way through peak boost it only happens right after a hard shift

 

When is the last time you checked your spark plugs?

 

Sounds like an accel enrichment issue. If you have the means you should pull a log to make sure the tps signal is normal during that period and also wideband afr to see if it's going lean right when you get back in the gas.

 

i just pulled and gapped all of them they were put in about 10k ago and i was having other bogging issues besides that but gapping them fixed that problem. i have some logs and i had a pull where it happened to me 1st 2ed and 3rd but no knock and smooth timing all the way through. i dont have my wideband hooked to my ecu or the connector so i couldnt log afrs

 

i just ran a 1st to 3rd pull and the afrs lean out to --- when it happens.

 

^^^ This. Add fuel to tip in or accel enrichment or whatever its called on an evo ecu lol.

 

Bumping this thread. Having this same issue. Anyone think the turbosmart dual port bov i am running could cause this? Car pulls really hard then if i shift fast into 3rd it falls on its face for a half second then kicks back in.

 

Knock sensor detecting noise.
Could be phantom knock.
Every 3 counts of knock 1 degree of timing is pulled.

 

Is your evo on maf or SD? Bov recirculated or vent to atmosphere?

 

maf. It's a turbosmart dual port set to 50/50

 

You figure this out? Im having the same issue.
When I drive normally, the first couple seconds the car loses power, goes lean to like 18afr then kicks back in around 2500rpm